A socket connector is revealed. The socket connector is electrically connected with a chip module onto a circuit board. The chip module includes a carrier board, at least one chip electrically connected to one side of the carrier board and a heat spreader arranged on another side of chip and placed opposite to the side of chip connected with the carrier board. The carrier board disposed with a plurality of contact members includes a base arranged with a plurality of receiving slots and part of the contact members being in the receiving slot, a plurality of conductive terminals arranged in the receiving slots and contact with the contact members, and a cover that has one side connected with the base and the opposite side connected with the chip module while the cover is disposed with a plurality of receiving holes corresponding to the receiving slots for being inserted by the contact members. At least one projecting seat is arranged on the cover, against the chip module for supporting the chip. The receiving holes penetrate the projecting seat. The socket connector not only has better thermal performance of the chip but also favors distribution of circuit board wiring.

The present invention relates to a socket connector, especially to a socket connector that favors distribution of circuit board wiring.
Due to progress of the society and increasing requirements of live standard, electronics have become essentials of people's lives. Now due to highly competitiveness of electronic industry, more and more manufacturers are dedicated to invent electronics with compact volume, light weight and excellent performance so as to increase market share. Here raise a problem—there is a dilemma that the electronics need to satisfy both requirements-compact volume and good cooling effect.
Refer to FIG. 1, a common socket connector 1 used in industries is revealed. The common socket connector 1 is electrically connected with a chip module 2 on a circuit board (not shown in figure). The common socket connector 1 includes a base 10, a plurality of conductive terminals (not shown in figure) in the base 10 and a cover 11 that is arranged over the base 10. The chip module 2 disposed on the cover 11 consists of a carrier board 20 set over the cover 11, a chip 21 arranged on the carrier board 20 and a heat spreader 22 disposed on the chip 21. The chip 21 is covered over the carrier board 20 while the chip module 2 also includes a plurality of conductive pins (not shown in figure) arranged on surface of the carrier board 20.
Although a surface 110 on one side of the cover 11 that connects with the carrier board 20 is a flat surface with the same height, while assembling the chip module 2 on the surface 110 of the cover 11, the carrier board 20 may still contact with the surface 110 of the cover 11 on multiple points, not surface contact due to wrong position of the chip module 2 or concave/convex areas on the surface of the carrier board 20. Thus the loading points of the carrier board 20 are uncertain and are not close together. Therefore, the chip 21 is not always keeping good contact with the heat spreader 22 and the heat conduction between the chip 21 and the heat spreader 22 is not good. This has negative effects on heat transfer of the chip 21 and may lead to damages thereof after being used for a long time.
As shown in FIG. 2, an improved socket connector 3 used broadly in industries is disclosed. The socket connector 3 is electrically connected with a chip module 4 onto a circuit board (not shown in figure). The socket connector 3 is formed by a base 30, a plurality of conductive terminals (not shown in figure) in the base 30 and a cover 31 that is arranged over the base 30. The chip module 4 disposed on the cover 31 includes a carrier board 40 disposed over the cover 31, a chip 41 arranged on the carrier board 40 and a heat spreader 42 set on the chip 41. The chip 41 is covered over the carrier board 40 while the chip module 4 also includes a plurality of conductive pins (not shown in figure) arranged on surface of the carrier board 40.
In order to improve thermal performance of the chip 41, a plurality of supportive projecting points 311 are disposed on a surface 310 of the chip module 4 connected with the cover 31 for supporting the carrier board 40 so as to make the loading points on the carrier board 40 get close to one another and the contact between the chip 41 and the heat spreader 42 become more closer. However, after being used for quite a long time, the carrier board 40 deforms due to loading points concentrated on the supportive projecting points 311 and thus the chip 41 and the heat spreader 42 are disconnected with each other. This also leads to poor conduction between the chip 41 and the heat spreader 42. Thus the thermal performance of the chip 41 is affected negatively. Therefore, the device is out of order after long term use.
Refer to FIG. 3, a socket connector (not shown in figure) formed by improving of the above socket connector 3 used widely in industries is revealed. The socket connector is electrically connected with a chip module (not shown in figure) onto a circuit board (not shown in figure). The socket connector (not shown in figure) includes a base (not shown in figure), a plurality of conductive terminals (not shown in figure) in the base and a cover 50 that is arranged over the base (not shown in figure). The chip module (not shown in figure) disposed on the cover 50 includes a carrier board (not shown in figure) disposed over the cover 50, a chip (not shown in figure) arranged on the carrier board (not shown in figure) and a thermal spreader (not shown in figure) set on the chip (not shown in figure). The chip (not shown in figure) is covered over the carrier board (not shown in figure).
In order to make the chip (not shown in figure) have better cooling effect, a plurality of supportive projecting points 501 is disposed on a surface 500 of the cover 50 connected with the chip module (not shown in figure) for supporting the carrier board (not shown in figure). At the same time, a projecting seat 502 is arranged for supporting the carrier board (not shown in figure). Insertion holes 503 on the cover are arranged surrounding the projecting seat 502 for receiving conductive pins (not shown in figure) of the chip module (not shown in figure).
Under the condition that the number of conductive pins of the chip module in this device, the number of the conductive pins (not shown in figure) of the chip module 2 of the socket connector 1, and the number of the conductive pins (not shown in figure) of the chip module 4 of the socket connector 3 are all the same, the cover 50 should be with larger area than the area of the cover 11 and the area of the cover 31 for disposition of the insertion holes 503 with the same number of the conductive pins (not shown in figure) due to the projecting seat 502. Thus this has negative effects on distribution of circuit board wiring.
Thus there is a need to develop a new socket connector that overcomes above shortcomings.


A cordless communication system includes a mobile terminal of a public mobile communication system and a base station. The base station is connectable to a public fixed network and compatible at an air interface with the mobile communication system which has at least one authentication function. A read and write unit of the base station reads and writes from and to, respectively, at least one identification module. Sections of data of the identification module used in the base station are identical to sections of data stored on a chip card of an access-authorized mobile terminal. The read data from the identification module is processed through software implemented in the base station. The mobile terminal is authenticated with regard to the base station through the processed data, wherein the base station fulfills the same functions and tasks as a home location register and, respectively, an authentication center of the mobile communication system. The mobile terminal is operated through the public fixed network if the authentication has been successful.

In today's mobile communication systems, a clear distinction exists between public mobile wireless systems, such as the GSM System and private cordless communication systems that operate according to, e.g., the in DECT standard [Digital European Cordless Telecomunication]. This has led to different system devices that can be used either for mobile wireless operation or for cordless operation.
Attempts have been made before to design terminals, in particular, mobile terminals, that can be used in two different mobile communication systems. However, due to the incompatibility of the different standards, relatively user-unfriendly and expensive solutions have resulted.
Another point of departure lies in arranging the base station of a cordless communication system in such a way as to make it compatible with a public mobile communication system, i.e., so that it can communicate with conventional mobile terminals. However, there is a lack of suitable suggestions for solving the problem of compliance with the required security functions. Herein the problem is that the base station of the cordless communication system is connected to a wire-bound fixed network, which makes it impossible to influence the base station via the mobile communication system.

Public mobile communication system compatible wireless communication system

Detemobil Deutsche Telekom Mobilnet GmbH


Chalcogenide nanowires and other micro-and nano scale structures are grown on a preselected portion of on a substrate. They are amorphous and of uniform composition and can be grown by a sublimation-condensation process onto the surface of an amorphous substrate. Among other uses, these structures can be used as coatings on optical fibers, as coatings on implants, as wispering galleries, in electrochemical devices, and in nanolasers.

The chalcogen elements (S, Se, and Te) are glass-formers. These elemental glasses are essentially chains that polymerize to varying lengths. Chalcogenide glasses are formed by combining chalcogen elements with Group III, IV or V elements, which are more electropositive than the chalcogens and lead to crosslinking. While some studies reveal large-scale medium-range ordering with correlation lengths up to about 50 Å, chalcogenide glasses are considered amorphous materials. Many chalcogenide glasses, for example arsenic based chalcogenide glasses such as As—S, As—Se, As—S—Se, As—Te, As—Se—Te, are semiconducting materials that transmit infrared (IR) light, rendering them useful in a variety of applications, such as IR sensors, waveguides, photonic crystals, amplifiers, lenses and as photolithography template materials. Rare earth doped chalcogenide glasses are also being investigated for highly efficient optical amplifiers and lasers.
Certain chalcogenides also have therapeutic properties and are being considered for a variety of treatments. For example, selenium, an essential trace mineral for normal metabolism, plays a protective role against cancer and can be used as an indicator of body status in cancer patients, for example in the form of a selenide, selenite (SeO32−) or selenate (SeO42−). In addition, at low concentrations, arsenic trioxide is an effective antileukaemic agent and shows promise for use against tumors that have become resistant to other anticancer drugs.
Despite the interest in chalcogenides, the ability to fabricate them on the micro and nanoscale has been limited. Accordingly, there is a need for novel systems and techniques for the nanofabrication of chalcogenides. The present invention addresses this need.


Container-type refrigeration systems. A container includes an upper beam assembly, a lower beam assembly, a first end wall assembly, and a second end wall assembly, the upper beam assembly is spaced from the lower beam assembly to form a first accommodation space between the upper beam assembly and the lower beam assembly, the upper beam assembly and the lower beam assembly each has one end connected to the first end wall assembly and the other end connected to the second end wall assembly to form a second accommodation space above the upper beam assembly and between the first end wall assembly and the second end wall assembly, the first accommodation space is isolated from the second accommodation space through the upper beam assembly, the second accommodation space has a water chilling unit.

A container is a large cargo container that has certain strength, rigidity, and specification and is specially designed for turnaround. To meet the requirements of refrigeration integration, fast delivery, and fast installation and operation, a corollary refrigeration system is installed on the container.
An existing container type refrigeration system can be put into use as long as water and electricity are connected after the system is deployed in an outdoor location. The refrigeration system generally adopts a container in a single-layer structure, or adopts more than 2 containers and other corollary devices. All refrigeration units of the refrigeration system are placed side by side.
In the process of implementing the present invention, the inventor finds at least the following problems in the prior art: with only one container, the refrigeration capacity is low; and with more than 2 containers and other corollary devices, the integration extent is low; the installation is complicated, which affects costs and construction duration; and the refrigeration units placed side by side make maintenance inconvenient.


A manufacturing method of a semiconductor device includes: a semiconductor substrate including a drain, a drift making contact with a front face of the drain, a body contacting with a front face of the drift, a source provided in part of a front face of the body, and a floating surrounded by the drift; and a gate including an insulator formed on an inner wall of a trench and a electrode disposed inside the insulator and which has a bottom portion contacting with the floating, the manufacturing method includes: forming the trench in a semiconductor wafer so as to have a bottom portion in which an end portion in a short direction perpendicular to a longitudinal direction thereof is deeper than a central portion; injecting an impurity ions into the bottom portion of the trench; and forming the central portion of the trench in the short direction to be deepened.

1. Field of the Invention
The present invention relates to a manufacturing method of a semiconductor device.
2. Description of Related Art
Japanese Patent Application Publication No. 2002-359378 (JP 2002-359378 A) describes a method for manufacturing a MOSFET including a floating p-layer around a bottom portion of a trench, by use of a semiconductor substrate made from silicon carbide. In a case where the semiconductor substrate made from silicon carbide is used, impurity is hard to diffuse in the semiconductor substrate, in comparison with a case where a semiconductor substrate made from silicon is used. Particularly, in a case where impurity is hard to diffuse in a direction perpendicular to an injection direction of impurity ions in a semiconductor substrate and the impurity ions are injected into a bottom portion of a trench to form a floating layer, the impurity ions thus injected are hard to diffuse in a plane direction of the semiconductor substrate. As a result, when a width of the floating layer in a short direction of a trench gate (a direction perpendicular to a longitudinal direction of the trench gate) is insufficient, a withstand voltage of a semiconductor device decreases. In the manufacturing method of JP 2002-359378 A, in a step of forming the floating p-layer, boron ions that are relatively easy to diffuse are injected in a deeper position of the semiconductor substrate, and aluminum ions that are relatively hard to diffuse are injected in a shallower position. Hereby, the width of the floating p-layer in a horizontal direction is widened in a deep position of the semiconductor substrate, but is narrowed in a shallow position.

Manufacturing method of semiconductor device


Disclosed is a velocity estimator using a level crossing rate. The velocity estimator comprises a power calculator for calculating power values of a signal received from a mobile terminal; a mean power calculator for calculating mean power values for M power values according to a predetermined down-sampling factor M; an interpolator for interpolating the mean power values according to a predetermined interpolation ratio L; a root mean square calculator for calculating a root mean square value using an output of the interpolator; a level crossing counter for counting a level crossing frequency representing how many times the output of the interpolator crosses a level crossing threshold determined according to the root mean square value, for a predetermined time period; and a velocity calculator for calculating a velocity estimation value of the mobile terminal using the level crossing frequency.

1. Field of the Invention
The present invention relates generally to wireless communication technology, and in particular, to an apparatus and method for estimating velocity of a moving object such as a mobile terminal.
2. Description of the Related Art
A 4th generation (4G) mobile communication system aims at supporting a dual mode functionality in which a mobile service by International Mobile Telecommunications 2000 (IMT2000) is unified with a fixed service by Wireless Location Access Network (WLAN). The 4th generation system adaptively assigns the mobile service and the fixed service to a user in such a way that it supports a high-capacity service in a fixed mode when the user's operation environment is excellent, whereas it supports a service in a mobile mode when the user's operation environment is poor.
Efficient management of a service mode must be continuously performed not only during initial access, but also during communication. To this end, an algorithm for efficiently performing initial mode selection, handoff and link adaptation of the mobile service and the fixed service is required. In particular, an adaptive modulation and coding scheme (AMCS), one of typical technologies for link adaptation, selects a modulation/coding scheme by determining parameters capable of indicating a user's operation environment and then estimating the values: The parameters indicating a user's operation environment are used as information for handoff between different modes and resource assignment of the adaptive modulation/coding scheme. For dynamic assignment of resources, accurate estimation for a user's operation environment is necessary.
In a wireless communication system, velocity information of a mobile terminal is an important parameter indicating a user's operation environment, and can improve system performance when it is actually applied. When applied to adaptive transmission/reception technology, velocity information of the mobile terminal enables a receiver to perform more efficient channel estimation and a transmitter to adjust a modulation/coding or interleaving scheme according to a channel condition. In addition, based on the velocity information of thea mobile terminal, the system can accurately determine whether to perform handoff or not, and a handoff time, and can efficiently manage system resources.
Such a velocity estimation scheme used in various application fields is classified into a level crossing rate (LCR) estimation scheme and a covariance (COV) estimation scheme. The level crossing rate estimation scheme estimates velocity using how many times an envelope, i.e., power, of a received signal crosses a predetermined reference level during a predetermined time period, i.e., the number of level crossings. The covariance estimation scheme estimates velocity of the mobile terminal, using a covariance value between received samples having a predetermined time difference.
Of the velocity estimation schemes, the covariance estimation scheme has a sensitive performance difference according to variation in channel environment parameters such as a Rician factor and an incidence angle of Line of Sight (LOS). In a micro-cell environment, it is difficult to stably use the covariance estimation scheme when Rician fading is considered. Compared with the covariance estimation scheme, the level crossing rate estimation scheme uses a level crossing rate which is a secondary statistical characteristic of an envelope fading and, for 2-dimensional isotropic scattering, velocity of a mobile can be calculated irrespective of a Rician fading characteristic.
However, since the conventional level crossing rate estimation scheme uses only a channel characteristic without considering an influence of noises, accuracy of velocity estimation is lowered undesirably in a noisy environment where a signal-to-noise ratio (SNR) is decreased. Thus, there is a need for a method of improving accuracy of velocity estimation when a level crossing rate is used in a low-SNR environment.

Velocity estimation apparatus and method using level crossing rate


Semiconductor integrated circuits (110) or assemblies are disposed at least partially in cavities between two interposers (120). Conductive vias (204M) pass through at least one of the interposers or at least through the interposer's substrate, and reach a semiconductor integrated circuit or an assembly. Other conductive vias (204M.1) pass at least partially through multiple interposers and are connected to conductive vias that reach, or are capacitively coupled to, a semiconductor IC or an assembly. Other features are also provided.

This document relates to semiconductor integrated circuits (ICs), and more particularly to assemblies with semiconductor integrated circuits.
Multiple ICs can be combined in a high-density assembly to provide needed functionality. High density is desired for small assembly size and also to shorten electrical paths as needed for high speed and low power consumption. However, a small IC is a fragile device with tiny, densely packed contact pads which must be connected to possibly larger contact pads of other integrated or non-integrated (discrete) circuits. To enable such connections, an intermediate IC (interposer) can be provided. Interposers may also increase the mechanical strength of the assembly, absorb stresses generated due to differences in coefficients of thermal expansion (CTE), and improve the ability to dissipate heat that can be generated during operation or manufacture. However, interposers increase the assembly size and complexity, and they should be as thin as possible to shorten the electrical connections through the interposers.
FIG. 1 illustrates an exemplary assembly 102 with interposers as described in U.S. pre-grant patent publication 2007/0235850 by Gerber et al., published Oct. 11, 2007, incorporated herein by reference. The assembly is connected to external devices 104.2, 104.1 by large solder balls 108. The assembly includes ICs 110.1, 110.2 attached from the bottom to respective larger ICs (interposers) 120.1, 120.2. A typical IC is fabricated in a wafer, and an IC can occupy a whole wafer, but an IC can also be part ("chip" or "die") of a wafer. In FIG. 1, ICs 110 (i.e. 110.1, 110.2) are dies attached to the interposers by connections 140 which are smaller, and denser packed, than solder connections 108. Interposers 120 are thicker and wider than dies 110.
In regions not occupied by die 110.2, interposer 120.2 is connected to interposer 120.1 by studs 154. In regions not occupied by die 110.1, interposer 120.1 is connected to an underlying insulator-based substrate 160 by other studs 154.
Each interposer 120 includes interconnects 158 each of which goes through the interposer and interconnects the interposer's circuits (not shown) coupled to connections 108, 140, 154. Insulator-based substrate 160 includes similar interconnects 164.
In manufacturing, ICs 110 and 120 and substrate 160 are separately manufactured and then attached to each other. Then the portion of assembly 102 above the substrate 160 is covered by an encapsulant (e.g. molding compound) 180 to mechanically strengthen the assembly. The assembly is then attached to external devices 104.
As noted above, it is desirable to reduce CTE mismatches, and thus the ICs 110 and 120 and the encapsulant 180 should preferably be made of materials with similar CTEs. However, a typical encapsulant (epoxy) has a much higher CTE than many ICs based on semiconductor materials such as silicon, so there is a need to reduce the encapsulant amount while still obtaining a robust assembly. Also, it is desirable to improve the mechanical strength and heat dissipation of intermediate structures obtained during manufacturing as well as the final structure.

Microelectronic assemblies with integrated circuits and interposers with cavities, and methods of manufacture


A process for removing impurities from 3-(2xe2x80x2-acetoxyethyl)dihydro-2(3H)furanone (I), where the 3-(2xe2x80x2-acetoxyethyl)dihydro-2(3H)furanone containing the undesirable impurities is initially prepared in a manner known per se by acetylation of 3-(2xe2x80x2-hydroxyethyl)dihydro-2(3H)furanone and the resulting product is subsequently subjected to a distillation or rectification, includes carrying out the distillation or rectification in a plurality of steps, where high-boiling impurities are removed in a first step, the product which is drawn off via the top is subsequently subjected to at least one further step in which low-boilers and intermediate boilers are drawn off via the top and the desired pure I is obtained as bottom product.

The present invention relates to a process for removing undesirable impurities from 3-(2xe2x80x2-acetoxyethyl)dihydro-2(3H) furanone of the formula I
3-(2xe2x80x2-Acetoxyethyl)dihydro-2(3H)furanone is a starting material for preparing methyl tetrahydropyran-4-carboxylate which for its part is an intermediate in the preparation of crop protection agents.
3-(2xe2x80x2-Acetoxyethyl)dihydro-2(3H)furanone is prepared, for example, by processes known per se and described, for example, in U.S. Pat. No. 5,350,863, starting from methyl acetoacetate and ethylene oxide. Another process variant from which 3-(2xe2x80x2-acetoxyethyl)dihydro-2(3H)furanone is obtainable is described in Dokl. Akad. Nauk SSSR 27, 956-959 (1940) and U.S. Pat. No. 5,283,326.
In both variants, the desired 3-(2xe2x80x2-acetoxyethyl)dihydro-2(3H)furanone is formed as a mixture with a number of undesirable byproducts, in particular the isomeric dihydro-3-(2-methyl-1,3-dioxolan-2-yl)-2(3H)-furanone II
If I which is contaminated in this manner is reacted in a continuous gas phase reaction with methanol in the presence of acidic catalysts to give methyl tetrahydropyran-4-carboxylate, the yields are significantly lower and the operating life of the catalyst is significantly shorter than when a product of high purity without byproducts is employed. This is probably due to the fact that most byproducts contain labile acetal groups which decompose on the surface of the catalyst to give oligomeric and polymeric products.
It is not possible to remove the undesirable byproducts, in particular the isomeric dihydro-3-(2-methyl-1,3-dioxolan-2-yl)-2(3H)furanone II adequately by simple batchwise distillation or rectification. In addition, during the batchwise distillation or rectification of 3-(2xe2x80x2-acetoxyethyl)dihydro-2(3H)furanone I containing the undesirable impurities, other low-boilers and intermediate boilers which are difficult to remove are formed, which recontaminate the purified I obtained in the distillate.
It is an object of the present invention to provide a process for removing undesirable byproducts, in particular II, and also newly formed low-boilers and intermediate boilers from mixtures with I.
We have found that this object is achieved by a process for removing impurities from 3-(2xe2x80x2-acetoxyethyl)dihydro-2(3H)furanone (I), where the 3-(2xe2x80x2-acetoxyethyl)dihydro-2(3H)furanone containing the undesirable impurities is initially prepared in a manner known per se by acetylation of 3-(2xe2x80x2-hydroxyethyl)dihydro-2(3H)furanone and the resulting product is subsequently subjected to a distillation or rectification, which comprises carrying out the distillation or rectification in a plurality of steps, where high-boiling impurities are separated off in a first step, the product which is drawn off via the top is subsequently subjected to a further step in which low-boilers and intermediate boilers are drawn off via the top and the desired pure I is obtained as bottom product.
Surprisingly, the process according to the invention affords a significantly higher degree of purity of the desired 3-(2xe2x80x2-acetoxyethyl)dihydro-2(3H)furanone (I) than in the customary sequence in the distillation or rectification where low-boilers and intermediate boilers are removed before the high-boilers and the product of value is drawn off at the top of the column. The reason for this is that, during the removal of the high-boilers, low-boilers and intermediate boilers are formed which can then not be removed in the customary sequence of the steps and which reduce the purity of the top product.
Preferred embodiments of the process according to the invention are shown in the subclaims and the description below.
The process according to the invention starts with the mixture of 3-(2xe2x80x2-acetoxyethyl)dihydro-2(3H)furanone (hereinbelow referred to as I) and undesirable impurities which is obtainable by known processes described in the introduction.
This mixture is generally prepared by acetylation of 3-(2xe2x80x2-hydroxyethyl)dihydro-2(3H)furanone. The preferred acetylating agent is acetic anhydride or acetic acid; however, in principle, all acetylating agents which are known to the person skilled in the art for corresponding acetylations are suitable. In general, the acetylation is carried out at temperatures in the range from 40xc2x0 C. to 200xc2x0 C., preferably from 60 to 140xc2x0 C., over a period of from 0.5 to 10 h, preferably from 0.8 to 5 h and in particular from 1 to 3 h.
To ensure complete acetylation, the acetylating agent is generally employed in a molar excess of from 5 to 50%, preferably from 5 to 20%, based on the 3-(2xe2x80x2-hydroxyethyl)dihydro-2(3H)furanone present in the mixture.
In a first preferred embodiment of the process according to the invention, the acetic acid formed as coproduct during the acetylation is firstly distilled off. By adding a suitable organic solvent and water, a phase separation is then carried out and the organic phase is subsequently extracted. Suitable organic solvents are in particular aromatic hydrocarbons and particularly alkylated benzene derivatives such as xylene or toluene. The organic extracts are combined and the solvent is then removed by a preliminary distillation or rectification step in at least one column, before the multistep distillation of claim 1 is carried out.
In another preferred embodiment of the process according to the invention, the product formed during the acetylation is treated with strong mineral acids before it is subjected to the rectification or distillation. Preferred mineral acids are hydrochloric acid and particularly preferably sulfuric acid. The latter is preferably employed in a strength of at least 80% and especially in the form of concentrated sulfuric acid.
The amount of acid used here can be varied within a wide range; in some cases, it has been found advantageous for the molar ratio of strong mineral acid, based on the amount of acetylating agent employed in the previous step, to be in the range of from 1:20 to 1:3, in particular from 1:15 to 1:7 and especially from 1:8 to 1:12.
During the treatment with the mineral acid, the temperature is generally in a range from 10 to 80xc2x0 C., preferably from 20 to 60xc2x0 C. and in particular from 30 to 50xc2x0 C. The duration of the treatment is generally in the range from 0.3 to 10 h, in particular from 1 to 5 h, but can, in principle, be varied within wide limits.
After the treatment with strong mineral acids, the decomposition products of the undesirable impurities, in particular of dihydro-3-(2-methyl-1,3-dioxolan-2-yl)-2(3H)-furanone II, can be removed in a simple manner. Particularly preferably, after the treatment with the mineral acid, the mineral acid is initially neutralized by addition of a base and the acetic acid formed as coproduct during the acetylation is subsequently, if appropriate, removed as described in the first preferred embodiment. This is then followed by the multistep distillation or rectification of claim 1.
The purity of I after the process according to the invention is generally at least 98% by weight, preferably at least 98.5% by weight and particularly preferably at least 99% by weight.
The I obtainable by the process according to the invention can be reacted in a known manner in high yield and with good catalyst operating life to give methyl tetrahydropyran-4-carboxylate. This is an important intermediate in the preparation of crop protection agents.

Removal of impurities from 3-(2xe2x80x2-acetoxyethyl)-dihydro-2(3H)furanone


Portable personal respiratory protection devices include a self-contained head gear member with a chin collar that has a front segment that defines a mouth portion and attaches to a back segment that resides over ears of a user and extends about a lower back segment of a head of the user. The head gear includes a visually transmissive face mask extending upwardly from the front segment of the chin collar that, in position, sealably engages a face of the user. The head gear has an open upper portion residing between an outer upper perimeter of the face mask and the back segment of the chin collar that, when worn, is adapted to expose a top and upper rear portion of a head of the user to environmental conditions.

The poultry industry has grown significantly over the past decade. There are emerging medical studies that show the health risks and effects of confined poultry work environments on workers. Farmers and other workers with prolonged exposure, e.g., five years or more of almost daily contact, are at a greater risk for respiratory complications and disease. In addition, agricultural workers can be exposed to other occupational hazards, such as heat-related deaths. Comfort and heat issues can be significant factors that determine whether workers wear suitable protective gear or not.
There remains a need for light-weight respirators that are suitable for agricultural use and that are configured to facilitate long term, chronic use of those respirators to inhibit occupational exposure to airborne particulates.

Portable respirators suitable for agricultural workers


A projection lens for a EUV microlithographic projection exposure apparatus comprises a diaphragm (BL) which is arranged at a distance (D) in front of a mirror (S2) of the lens. The diaphragm (BL) has a non-round aperture with an edge contour that may be configured such two rays of a light bundle disposed symmetrically with respect to a chief ray are treated equally, i.e. either both rays pass through the diaphragm aperture or both are blocked by the diaphragm.

1. Field of the Invention
The invention relates to a projection lens for a microlithographic projection exposure apparatus, and in particular for a projection exposure apparatus designed for projection light in the short-wave UV and EUV range.
2. Description of Related Art
In microlithography projection lenses with mirrors as imaging components are used for projection light in the short-wave UV and EUV ranges. For example, EP 1 178 356 A2 discloses a projection lens for microlithography which has six coaxial mirrors. This known projection lens has a diaphragm which is arranged on the second of the six mirrors of the lens.
Because the diaphragm is combined with one of the mirrors it is possible to change the diaphragm aperture only with great difficulty. The whole mirror supporting the diaphragm must be removed and replaced by an optically equivalent mirror supporting another diaphragm. This means that the lens must be readjusted, and care must be taken to close the lens again in a vacuum-tight manner and to re-evacuate the lens.

Projection lens for a microlithographic projection exposure apparatus


Provided is a wireless power transmitting unit capable of auto-tuning according to impedance change. The wireless power transmitting unit according to an embodiment can stabilize the operation of the amplifier by changing the resonance frequency of the resonator without measuring the phase information about the resonator.

In Alliance for Wireless Power (A4WP), which is a wireless charging standard using a frequency of 6.78 MHz, the impedance of a load is reflected in a wireless power transmitting unit (PTU), and therefore the operation point and output power of an amplifier constituting the PTU are determined by the impedance of the load. Accordingly, an auto-tuning circuit for tuning a resonator according to the impedance of the reflected load to ensure a stable operation point and smoothly transmit the output power is required.
There is a technique for detecting a voltage/current of the resonator to determine the phase and operate the resonator such that the resonator has a similar resonance point according to change in impedance of the load. However, with the technique of A4WP, it is not easy to realize a circuit capable of accurately detecting the phase because the resonance frequency of the resonator is as high as 6.78 MHz and the voltage of the resonator can reach several hundreds of volts.

Wireless power transmitter capable of automatic adjustment according to impedance change


An internal combustion engine with rotatable bodies each received in a respective internal cavity. The engine includes at least one inlet port for each internal cavity in fluid communication with the combustion chamber(s) thereof at least during their intake phase and a beginning of their compression phase. The bodies are angularly offset with the beginning of the compression phase of the combustion chamber(s) defined by each body being simultaneous with at least a beginning of the intake phase of the combustion chamber(s) defined by a different one of the bodies. A respective conduit provides a fluid communication between an inlet port for each body and an inlet port for the different one of the bodies, with each conduit being in fluid communication with a plenum for receiving pressurized air. A method of feeding air to an internal combustion engine is also provided.

Internal combustion engines operating under the principle of the Miller cycle usually have an open inlet port during the beginning of the compression phase of the combustion chamber(s). In a reciprocating engine, the Miller cycle may be obtained through timing of the opening of the inlet valve. In a rotary engine such as a Wankel engine, the Miller cycle may be obtained through proper positioning of the inlet port. The Miller cycle engine usually has a volumetric compression ratio lower than its volumetric expansion ratio.
Typically, the Miller cycle engine is used with a turbocharger to prevent loss of air during the beginning of the compression phase and to increase the pressure compression ratio. However, during the beginning of the compression phase when the inlet port is open, compression must be typically performed against the pressure of the turbocharger, which usually creates pressure losses.

Internal combustion engine with port communication


A rack that adjustably attaches to an inboard wall panel of a boat for securing water sport equipment in the cockpit of the boat. The device is configured so that the rack adjustably attaches to the inboard wall panel and rests flush against the floor of a boat. The device is designed to secure a variety of water sport equipment so as to protect the water sport equipment, the boat and the passengers.

1. Field of the Invention
A water sport equipment rack for safe and secure transport in a boat is provided. More specifically, a rack is disclosed that is designed to hold various water sport equipment and to attach to the inside wall panel of a boat by an adjustable apparatus to improve the method of supporting and stabilizing the water sport equipment and to protect the water sport equipment, the boat, and the passengers.
2. Description of the Background Art
Water sports have become, with increasing participation, a popular sport for competition and recreation. With a variety of water sport equipment now available to be used in connection with a boat, an adequate holding device to accommodate the variety of water sport equipment is necessary to provide storage, support and stability to the equipment and to provide protection and safety to the equipment, the boat, and the passengers.
Many new models of boats now have provisions for the storage of the current variety of water sport equipment. However, older models and some new models of boats do not have provisions for storage; consequently, the water sport equipment is loosely placed in the boat, often on the floor, posing a harm to the equipment, the boat, or the passengers.
Several racks for storage of water sport equipment have been devised in the past for securement of the equipment on a boat during transport. However, none has been devised to attach to the inboard wall panel, and none is devised to accommodate the current variety of water sport equipment now available.
U.S. Pat. No. 3,811,143 introduces a water ski holder that mounts to an engine of an inboard motor boat. The disclosed rack is devised to store water skis on the rack above the engine. A resilient member straps over the water skis to secure them in place. The rack also includes a hook for attachment of a tow rope.
Disclosed in U.S. Pat. No. 3,925,836 is a ski rack that mounts on the exterior transom of a boat. This invention is a rack that extends upward over the outboard engine and secures water skis outside of the cockpit of a boat.
U.S. Pat. No. 4,056,220 presents a portable device for storage of water skis and tow ropes. The portable device mounts on the transom of a boat, extending out of the cockpit of the boat.
A ski rack is introduced in U.S. Pat. No. 4,234,112 having tubular posts that mount, by means of suction cups, to the horizontal top and vertical side external surfaces of a boat, thus exterior to the cockpit. The rack is devised to hold up to two pairs of water skis that would stack on top of the other.
Disclosed in U.S. Pat. No. 4,330,065 is a portable water ski rack. The disclosed portable rack is intended to be mounted over the boat engine with securement of the rack to either the engine or the boat frame. The disclosed rack is also designed only for securement of water skis, and not other current water sport equipment.
Related in U.S. Pat. No. 4,582,015 is a rack for supporting water skis exterior to the cockpit of a boat. The rack has a pair of support members that attach to the gunwale of the boat with the support members extending outside the side of the boat.
A water ski storage rack is disclosed in U.S. Pat. No. 4,858,802. The disclosed rack is devised as a V-shaped support for water skis and the like that resiliently connects to a lower support element. The rack is intended to be mounted on a boat, outside of the cockpit. The rack supports water skis and the like by stacking a set of skis on top of the other.
U.S. Pat. No. 4,863,082 discloses a lockable water ski rack having a lower support base hinged to an upper support frame that closes and locks the water skis in place. This rack mounts to the gunwale or transom of a boat, outside of the cockpit. The rack is intended to hold water skis and the tow rope.
U.S. Pat. No. 5,105,754 discloses a water ski rack fashioned with support legs that position over and attach to the boat engine cover. The disclosed rack is devised to be utilized as an apparatus to secure water skis and to be utilized as a tow hook for use in towing a skier. The disclosed rack is devised only to secure water skis and not other current water sport equipment.
The foregoing patents reflect the state of the art of which the applicant is aware and are tendered with the view toward discharging applicant's acknowledged duty of candor in disclosing information which may be pertinent in the examination of this application. It is respectfully submitted, however, that none of these patents teaches or renders obvious, singly or when considered in combination, applicant's claimed invention.


A combination switch and circuit breaker is operative as both a switch and circuit breaker when connecting a load to an auxiliary power supply, but is only operative as a switch when connecting the load to a main power supply. The combination switch and circuit breaker has a switch component for selectively connecting a load center branch circuit to either a main power supply or an auxiliary power supply. During main power interruption, for example, the switch component of the combination switch and circuit breaker may electrically connect a branch circuit of the load center to an auxiliary power supply, with a circuit breaking component providing current overload protection. However, during normal main power operation, the switch component electrically connects the load center branch circuit to main power, with a branch breaker and a main breaker providing current overload protection for the branch circuit.

The present invention relates generally to transfer switches and, more particularly, to a combination transfer switch and circuit breaker.
Transfer switches are designed to selectively electrically connect a load to one of two power supplies. Representatively, a transfer switch may be used to connect an electrical load, to either a main power supply, such as a utility power supply, or an auxiliary power supply, such as an electric generator. In most conventional applications, the transfer switch will have a single-pole, double-throw switch for each branch circuit of a load center or main panel that is to be powered by the auxiliary power supply during interruption of the main power supply. Each switch is operable in either a LINE position, which is its normal operating position when the main power supply is supplying power to the branch circuit, or a GEN or AUX position in which the auxiliary power supply is used to supply power to the branch circuit. Conventional transfer switches have been designed to have separate branch circuit switches and circuit breakers for each branch circuit to be fed when connected to receive power from the auxiliary power supply.
Combination switch and circuit breakers have been designed to overcome some of the drawbacks associated with separate switch and circuit breaker arrangements. Specifically, single-pole, single-throw combination switch and circuit breakers have been developed to provide switching and circuit breaking functionality in a single device. While reasonably effective, these combination switch and circuit breakers are constructed to have only an ON position or an OFF position. That is, current flow is only permitted between a single power supply and a load (branch circuit) when the combination switch and circuit breaker is in the ON position. When in the OFF position, current is prevented from flowing from the power supply to the load. Because the combined device provides some overcurrent protection, it may automatically move to the OFF position if an excessive current condition is detected while in the ON position. While such combination devices have reduced the size and complexity of transfer switches, these combination devices only permit connection to a single power supply, typically the auxiliary power supply. Therefore, to connect the branch circuit to the main power supply, a switch device must be used that is separate from the switch device used to connect the branch circuit to the auxiliary power supply.


A canceling method and apparatus can achieve a fast communication by improving an S/N value by adaptively canceling a noise with respect to a frequency or band having a large noise by selecting noise canceling band in accordance with a condition of noise being generated. A reception signal contains a specific signal having a specified time position, amplitude and phase. A noise distribution of the specific signal is recognized so as to predict a noise by extracting a frequency band having a larger noise component from a pair of frequencies generated by the insertion of the specific signal. An original transmission signal is reproduced by canceling the predicted noise from the reception signal.

1. Field of the Invention
The present invention generally relates to noise canceling methods and apparatuses and, more particularly, to a noise canceling method and apparatus for accurately extracting signals buried in noises in communications under a large noise circumstance.
Such a noise canceling method and apparatus is preferably applicable to apparatuses over various fields as mentioned below.                a modem for power-line carrier communication for achieving fast data transmission using an electric line such as a power line having many noises;        a CATV modem, an ADSL modem, a VDSL modem, a radio LAN of 2.4 GHz band, other radio transmission fields and an optical transmission field;        a magnetic disk drive units or optical disk drive unit for achieving achieve high-density recording by enabling an extraction of signals which tend to be buried in noise under a high-speed operation;        a semiconductor device using a fast multi-value transmission technology; and        a demodulation device of a voice recognition apparatus, an image compression apparatus and a barcode scanner under a noisy circumstance.
2. Description of the Related Art
Although a description will be given of an example in which the present invention is applied to a modem for power-line carrier communication as an apparatus used under a high-noise circumference, the present invention is also applicable to an apparatus of various fields.
As shown in FIG. 1, a power of a power supply transformer station 24-1 is supplied to a pole transformer 24-3 via a high-voltage line 24-2 of 6.6 kV, and further supplied to a house 24-6 via a low-voltage line 24-4 of 100 V/200 V and a branch line 24-5.
When a power-line carrier communication is performed in the above-mentioned power line system, an optical fiber (not shown in the figure) is provided between an access node 24-11 of the power supply transformer station 24-1 and the modem provided to the pole transformer 24-2 in parallel to the high-voltage line 24-2 so as to transmit the communication signals via the optical fiber. The communication signals are transmitted between the pole transformer 24-3 and the house 24-6 via the 100 V/200 V low-voltage line 24-4 between a modem, which is plugged into a receptacle connected to interior wiring 24-7 within the house 24-6 and a modem of the pole transformer 24-3.
The above-mentioned power line system is considered The low-voltage line 24-4 is considered to be an inductor of 1 μH/m as shown in FIG. 2B with respect to a spectrum of a transmission signal TX from the modem of the pole transformer 24-3. If the length of the low-voltage line is 150 m, it is considered to be an inductor of 150 μH/m. Additionally, the branch line 14-5 connected to the low-voltage line 24-4 is considered as a capacitor of 75 pF/m. If 50-m branch lines corresponding to 30 houses are connected to the interior wiring 24-7, the branch lines are considered as a capacitor of 0.1125 μF. In addition, each of various electrical appliances connected to the interior wiring 24-7 is provided with a radio interference suppression capacitor between the AC 100 V lines, which provides a large capacitive load.
As a result, when viewing the low-voltage line from the pole transformer 24-3, the low-voltage line is considered as a low-pass filter (LPF) of a low-pass type as shown in FIG. 2B, and a high-frequency component of the reception signal RX greatly attenuates as shown in FIG. 2C. Accordingly, in worst case, the high-frequency component may be buried in noises N when the high-frequency component reaches a communication terminal in the house.
On the other hand, although the low-frequency band component does not attenuate as much as the high-frequency band component, the low-frequency band component is also buried in a large noise N as shown in FIG. 2C since an extremely large amount of random noise (white noise) is emitted from electric appliances using a switching power supply or an inverter device. Accordingly, a fast data communication using a power-line carrier has not been put into practical use, and there has been a demand for finding a solution for a long time.
As a solution of such an issue, various modulation method such as an FM modulation method, an FSK modulation methods or a PSk modulation method, which are said to be resistant to a noise, has been used as a modulation method of a modem for the power-line carrier communication. However, a limited application has been made in practice, such as an application related to a low data transmission speed of less than 1200 bps since the power line has an extremely large noise level.
Additionally, although an attempt has been made to put the power-line carrier communication using a spread spectrum method in practical use, a transmission capacity sharply decreases when an S/N value is a minus value as shown in FIG. 2C under a white noise circumstance. The transmission rate is 100 kbps at maximum, and it becomes incapable of carrying out communication in worst case. Further, an orthogonal frequency division multiplexing (OFDM) method using a multi-carrier modulation method has been introduced so as to attempt an application of a technology to carry out communication while avoiding a carrier band having a lot of noises.
However, the number of switching power source and inverter devices in home electric appliances, which are main source of noises, tends to increase, and it has become further difficult to avoid an attenuation of high-band signals due to the capacitive load. Accordingly, the power-line carrier communication can be put in a practical in a low-speed communication, but it is impossible to achieve the power-line carrier communication at a high rate as high as a few Mbps.
In the future, the number of switching power source and inverter devices in home electric appliances will be increased, and it will become further difficult to avoid an attenuation of high-band signals due to the capacitive load. Under such circumstances, the communication being carried out while avoiding noises in the prior art is not sufficient. Rather, it is effective to positively take measures for noise so as to achieve a fast communication by canceling or removing the noise.
The applicants discloses, in Japanese Patent Application No. 2000-359949 titled "noise canceling method and apparatus", the invention to achieve a fast communication by reproducing reception signals buried in noises, if the S/N value is minus as shown in FIG. 2C, by canceling a low-band noise component having a small signal attenuation. The invention of the prior application extracts reception signals buried in noises by turning the S/N value to a plus value by removing a noise component in a dominant band with respect to a colored noise in a macroscopic view. The band of noise to be canceled is fixed within a predetermined range, and it is effective to a case in which the noise component is particularly concentrated into a low band.
However, there is a case in which a noise having a comb-like spectrum distributed in a wide band is generated due to a noise of use of an inverter provided equipped in home electric appliances or a frequent band noise generated by radio interference by AM broadcasting carrier. In such as case, if only a noise within a predetermined range is cancelled, the S/N value deteriorates which generates frequent reception errors since noises in ranges other than the noise canceling band remain uncanceled.


The present invention discloses a source electrode driving module for providing a data signal to an LCD unit, comprising: a Gamma correction chip and a source electrode driving chip, wherein, the Gamma correction chip comprises a P-GAMMA driving chip with three to eight output channels; the P-GAMMA driving chip is used for generating multiple control voltages providing to the source electrode driving chip; the source electrode driving chip comprises a first resistor string and a second resistor string; the multiple control voltages generated by the P-GAMMA driving chip connect into the first resistor string and the second resistor string according to turning points of a Gamma curve of the LCD unit, wherein, n is an integer, and 6≦n≦10. The present also disclose an LCD panel including the source electrode driving module described above.

1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device technology field, and more particularly to a source driving module of an LCD panel and an LCD panel comprises the source driving module in an LCD device.
2. Description of Related Art
The liquid crystal display (LCD) device is a flat and ultra-thin display device. It consists of a number of color or monochrome pixels, placed in front of the light source or reflect surface. The power consumption of the LCD device is very low, and it has a high-quality, small size, light weight, so that people are favored to become the mainstream display device. The current LCD device is mainly based on the thin film transistor (TFT). The LCD panel is the main component of the LCD device. The liquid crystal panel generally includes a color filter substrate and a TFT array substrate disposed oppositely and a liquid crystal layer sandwiched between the two substrates.
The driving of the LCD panel is by the gate electrode driving module and the source electrode driving module to respectively provide a scan signal and a data signal to the LCD unit. The voltage difference between different voltage of the data signal and a common electrode voltage cause the liquid crystal molecular to rotate a different angle in order to form the brightness difference. That is, the LCD panel displays with different grayscales. In the LCD panel, the relation curve between the data signal voltages and grayscales is called a Gamma curve. Using 8bit LCD panel as an example, it can display 28=256 grayscales, and they are corresponding to 256 different Gamma voltages. The Gamma voltages divide the change process from white color to black color into 2N equal parts.
In order to improve the display quality of the LCD panel, the Gamma correction has been widely used. In practical application, it usually selects the crucial turning points in the Gamma curve, and through adjusting the voltages of turning points to achieve adjustment of the Gamma curve. Using LCD panel with 256 grayscales as an example, in order to protect the LCD unit better, for the same display unit, it usually utilizes mutual driving method of a positive polarity voltage and a negative polarity voltage. In the Gamma curve as shown in FIG. 1, VD1˜VD20 have 20 turning points (00H, 01H, 02H, 1FH, 3FH, 7FH, BFH, DFH, FEH and FFH, that is the 0, 1st, 2nd, 31rd, 63rd, 127rd, 191rd, 223rd, 254rd and 255rd grayscales) to be selected for adjusting, which is that we usually refer to 20 regulated voltages with binding. The source driving IC further generates 256 Gamma voltages according to the 20 regulated voltages to realize the display of 256 grayscales as the schematic diagram shown in FIG. 2.
In the prior art, there are two methods to generate VD1˜VD20: one method is using a resistor string to divide a voltage to obtain 20 regulated voltages, and then utilizing buffer amplifier chip to amplify the driving capacity. However, the Gamma voltages generated by this method are difficult to adjust; the other method is using P-Gamma (programmable gamma correction) to implement programmable regulated voltages. The Gamma voltages generated by this method is easy to be adjusted, but using P-Gamma IC to generate 20 regulated voltages, the number of the output channels is more, and the cost is higher.

Source electrode driving module with Gamma correction and LCD panel

Shenzhen China Star Optoelectronics Technology Co., Ltd


A dartboard cover for covering a dartboard in an aesthetically pleasing manner wherein the dartboard cover includes a frame having a central aperture and a graphic panel removably mountable in the central aperture. A rib extends from a rear surface of the frame and is removably engagable with an upper edge of the dartboard to removably mount the dartboard cover to the dartboard.

Present invention relates generally to a cover for a dartboard and, more particularly, to a dartboard cover that is adaptable for displaying various graphics to create a desired ornamental appearance as opposed to an exposed dartboard on a wall. Dartboard cabinets are commercially available and relatively well known by those skilled in the art of darts and dart supplies. A typical dartboard cabinet is rectangular, constructed of wood and fixed to a wall at a predetermined dartboard playing height. The dartboard cabinet typically includes a pair of hinged front doors that alternately cover and expose a dartboard that is mounted within the cabinet. The hinged doors may include a scoreboard on an inner surface and an outer surface of the doors may include a carved or painted image that is permanently adhered to the doors and is not adaptable to modification.
It would be desirable to develop a dartboard cover that is not fixed to the wall, thereby requiring holes in the wall, is generally lightweight and includes a high quality or other graphic that is adaptable to user preferences.


The present invention relates to a cache memory management system suitable for use with snapshot applications. The system includes a cache directory including a hash table, hash table elements, cache line descriptors, and cache line functional pointers, and a cache manager running a hashing function that converts a request for data from an application to an index to a first hash table pointer in the hash table. The first hash table pointer in turn points to a first hash table element in a linked list of hash table elements where one of the hash table elements of the linked list of hash table elements points to a first cache line descriptor in the cache directory and a cache memory including a plurality of cache lines, wherein the first cache line descriptor has a one-to-one association with a first cache line. The present invention also provides for a method converting a request for data to an input to a hashing function, addressing a hash table based on a first index output from the hashing function, searching the hash table elements pointed to by the first index for the requested data, determining the requested data is not in cache memory, and allocating a first hash table element and a first cache line descriptor that associates with a first cache line in the cache memory.

The present invention relates to cache memory management and snapshot operations in a data storage system.
This application also incorporates by reference herein as follows:
U.S. application Ser. No. 10/264,603, Systems and Methods of Multiple Access Paths to Single Ported Storage Devices, filed on Oct. 3, 2002, now abandoned;
U.S. application Ser. No. 10/354,797, Methods and Systems of Host Caching, filed on Jan. 29, 2003, now U.S. Pat. No. 6,965,979 B2;
U.S. application Ser. No. 10/397,610, Methods and Systems for Management of System Metadata, filed on Mar. 26, 2003, now U.S. Pat. No, 7,216,253 B2;
U.S. application Ser. No. 10/600,417, Systems and Methods of Data Migration in Snapshot Operations, filed on Jun. 19, 2003, now U.S. Pat. No. 7,136,974 B2;
U.S. application Ser. No. 10/616,128, Snapshots of File Systems in Data Storage Systems, filed on Jul. 8, 2003, now U.S. Pat. No. 6,959,313 B2;
U.S. application Ser. No. 10/677,560, Systems and Methods of Multiple Access Paths to Single Ported Storage Devices, filed on Oct. 1, 2003, now abandoned;
U.S. application Ser. No. 10/696,327, Data Replication in Data Storage Systems, filed on Oct. 28, 2003, now U.S. Pat. No. 7,143,122 B2;
U.S. application Ser. No. 10/837,322, Guided Configuration of Data Storage Systems, filed on Apr. 30, 2004, now U.S. Pat. No. 7,216,192 B2;
U.S. application Ser. No. 10/975,290, Staggered Writing for Data Storage Systems, filed on Oct. 27, 2004;
U.S. application Ser. No. 10/976,430, Management of I/O Operations in Data Storage Systems, filed on Oct. 29, 2004, now U.S. Pat. No. 7,222,223 B2;
U.S. application Ser. No. 11/122,495, Quality of Service for Data Storage Volumes, filed on May 4, 2005;
U.S. application Ser. No. 11/245,718, A Multiple Quality of Service File System, filed on Oct. 8, 2005; and
U.S. application Ser. No. 11/407,491 Management of File System Snapshots, filed Apr. 19, 2006.
A data storage system may use snapshots for backup, data mining, or testing of software programs in development. A snapshot is a usable image of the data at an instant in time. The snapshot results in two data images: (1) the original data that can be read and written by applications as soon as the snapshot is created, and (2) the snapshot that can be backed up or mined. Some techniques allow a snapshot to be modified while others create read-only images. One technique of snapshot is copy-on-write. In copy-on-write, upon getting a request to store modified data, the data storage system first copies the original data to a target storage space before permitting the modification to be written to its source storage space. The need for high data availability in data storage systems may require making frequent snapshots of data. However, frequent snapshots consume system resources such as cache memory, the internal memory bandwidth, storage device capacity and the storage device bandwidth.

Methods and systems of cache memory management and snapshot operations


A base station assigns a most appropriate carrier from wide frequency bands in response to a re-request for channel establishment received from a mobile station, even if a same slot as a slot last assigned is assigned. Furthermore, a frequency management table is managed in which carriers that form a radio channel and are grouped by a specific number thereof so as to be distributed over wide frequency bands. Priorities used to search groups are individually provided for base stations that form a system. This allows neighboring base stations to distribute carriers over the wide frequency bands.

A conventional radio channel assignment method is explained below.
The conventional radio channel assignment method includes, for example, an autonomous distributed dynamic channel assignment scheme in which each of two or more radio base stations perform channel selection/assignment autonomously without exchanging control information between other radio base stations (see Patent Literature 1).
When there is a call, the conventional autonomous distributed dynamic channel assignment scheme allows a base station or a mobile station to select all of radio channels which are used by a system. Each of base stations cyclically measures received levels of interference at radio channels, channel-by-channel, and enters radio channels, at which the received level of the interference is an allowable value or less in the system, in an idle channel table on a memory of the system in order of detection of the radio channels and by the fixed number thereof.
Furthermore, upon switching of radio channels or upon finishing of communication, each of the base stations sets the order of received-level measurement of interference at a radio channel to the highest order, the radio channel at which no interference is affected during communication and which is released thereafter. Each of the base stations also sets the order of received-level measurement of interference at a radio channel to the lowest order, the radio channel at which interference is affected during communication and which is released thereafter.
When there is a call, the base station refers to the memory of the system and determines whether the communication link quality satisfies the allowable value of the system in the order from the radio channel that is entered in the idle channel table as the highest order. The base station then selects the radio channel initially determined that the quality is satisfied, and uses it for communication.
Patent Literature 1: Japanese Patent No. 3244153, Channel assignment method.
However, in a radio communication system in which the channel assignment method described in the above patent literature is used, the base station refers to the received levels of interference cyclically measured. Therefore, this system does not recognize the received level of interference at the transmission timing. Because of this, if a re-request of radio channel assignment or a radio channel switching request is received from a mobile station, and if switching is instructed by a base station, instead of assigning a carrier that is appropriate at the transmission timing, a carrier near a carrier that is last assigned is generally assigned.
Furthermore, in the radio communication system in which the conventional channel assignment method is used, in neighboring base stations, for example, there is a case where carriers, at which a received level measured value of interference satisfies an allowable value or less in the system, may overlap, and a timing of assigning a radio channel may be close to another timing. In this case, the assigned carriers overlap, which increases the interference between base stations.
The present invention has been achieved to solve at least the conventional problems. It is an object of the present invention to provide a radio channel assignment method capable of assigning an appropriate carrier at a transmission timing, as a radio channel, (capable of reducing probability of assigning a carrier near a carrier that is last assigned), if a re-request of radio channel assignment or a switching request thereof is received from a mobile station or if switching is instructed by a base station.
It is another object of the present invention to provide a radio channel assignment method capable of reducing interference between base stations through distribution of carriers, which can be assigned, over wide frequency bands by a neighboring base station.


The disclosure provides methods for the treatment and prevention of periodontal disease. In preferred embodiments, the invention provides for local treatment of periodontal tissues with a pharmaceutical composition including an immune response modifier (IRM) selected from the group of immune response modifiers comprising imidazoquinoline amines, imidazopyridine amines, 6,7-fused cycloalkylimidazopyridine amines, imidazonaphtyridine amines, oxazoloquinoline amines, thiazoloquinoline amines and 1,2-bridged imidazopyridine amines.

Periodontal disease or periodontitis is an inflammatory disease that results in the destruction of both the hard and soft tissues supporting the teeth and has recently been hypothesized as a risk factor for cardiovascular disease. Beck et al. "Dental Infections and atherosclerosis," American Heart Journal 13:S528–533 (1999). It is estimated that over 10 million people in the United States are currently being treated for the more serious forms of this disease, with approximately 8 billion dollars spent for treatment each year.
Clinically, periodontitis is an inflammation of the periodontium and results in inflammation of the gingiva and may result in resorption of alveolar bone and recession of the gingiva Recession of the gingiva can lead to exposure of the periodontal ligament allowing microorganisms to invade and destroy the ligament.
Infection by a few essential species of bacteria is important in initiating the host inflammatory response that is responsible for the tissue destruction and ultimate loss of teeth. Zambon, J. J., "Periodontal Disease, Microbial Factors," Ann. Periodontol., 1:879–825 (1996). The major pathogens associated with the disease have been identified and include Porphyromonas gingivalis, Bacteroides forsythus and Actitiobacillus actinomycetemcomitans. Although essential to the pathogenesis, bacteria alone are insufficient to cause the disease. Host factors such as hereditary predisposition and environmental factors such as smoking are believed to equally effect disease occurrence and severity of outcome.
Forms of periodontitis include early onset periodontitis (EOP), chronic adult periodontitis (AP), and refractory periodontitis (RP). Localized juvenile periodontitis is a form of EOP which occurs in otherwise seemingly healthy adolescents and is associated with infection by A. actinomycetemcomitans. "Chronic adult periodontitis" is commonly associated with the presence of B. forsythus, P. gingivalis, many gram-negative asaccharolytic rods, and oral spirochetes. It typically occurs in patients over 35 years of age. Clinically, it resembles acute necrotizing ulcerative gingivitis imposed on rapidly progressive periodontitis. Patients may lose 9 to 12 mm of gingival attachment in as little as six months.
Current treatment for periodontal disease is almost exclusively mechanical and surgical in nature most frequently including scaling and root planing to remove calculus deposits. However, the mechanical treatments do not affect the underlying cause of disease. Antibiotics have also been used as an adjunct therapy, Loesche et al, "Treatment paradigms in periodontal disease", Compend. Contin. Educ Dental, 18(3):221–6, 228–30 (1997). Unfortunately, results have been disappointing because the antibiotic may not eliminate the bacteria responsible for the inflammatory component, and patients are subject to re-infection.
Accordingly, there is a continuing need for new and effective treatment and preventive measures for periodontal disease. The present invention is directed to this need.

Methods for the treatment of periodontal disease


An IC socket which can be used commonly in IC packages whose outer leads are different from each other. A receiving base having a stepped bottom surface on which an IC package is placed is movably disposed in a first hole of a main body portion of the IC socket. A sliding member having a stepped top surface is brought into abutment with the stepped bottom surface of the receiving base and is movably disposed in a second hole of the main body portion. By sliding the sliding member, the height of the receiving base can be changed in steps in accordance with the stepped bottom surface, making it possible to change the height of the receiving base according to the shape of the outer leads of an IC package placed on the receiving base.

1. Field of the Invention
The present invention relates to an IC socket for use in functional testing and the like of an IC package.
2. Description of the Related Art
FIG. 11 is a perspective view illustrating a conventional IC socket. In this figure, a receiving base 2, which is formed in one piece with a main body portion 10 of an IC socket, is disposed in the center of the main body portion 10 of the IC socket. An IC package (not shown) is placed on the receiving base 2. A plurality of contactors 5 supported on the main body portion 10 are disposed on both sides of the receiving base 2. These contactors 5 have spring properties, and their top ends which extend toward the receiving base 2 make electrical contact with corresponding outer leads (not shown) extending from both sides of the package portion of an IC socket. A pressing lid 14 having a pressing member 3 is designed to hold an IC package against the receiving base 2.
When, for example, an IC package having regular bend leads, e.g., a SOP (Small Outline Package) type, in which outer leads are bent toward the bottom surface thereof, is placed on the receiving base 2, the IC package is positioned by the receiving base 2. Upon closure of the pressing lid 14, the outer leads of the IC package are pressed against the corresponding contactors 5 by the pressing member 3, thus causing the outer leads to make electrical contact with the contactors 5.
In the conventional IC socket described above, the height of the receiving base 2 is constant because the main body portion 10 and the receiving base 2 are formed in one piece. The shapes of the outer leads of IC packages include, in addition to the shape of a regular bend lead type, a flat lead type in which the outer leads extend horizontally from the package portion, and a reverse bend lead type in which the outer leads are bent upwardly. Thus, the height of the top end portion of the outer leads varies. Consequently, there is a problem in that it is not possible to use just one IC socket due to the fact that if the shape of the outer leads of IC packages having the same shape varies, the outer leads cannot make contact with the contactors 5.
If a reverse bend lead type package is turned upside down, the outer leads thereof have the same shape as that of the regular bend lead type. However, since the arrangement of the outer leads varies, the IC socket cannot be used in practice even if contact with the contactors 5 can be obtained.


The present invention discloses a stabilizing apparatus for avoiding auto-resetting of a dry etcher system. The ripples of direct current are eliminated by applying capacitors connects across the testing points of the power supply. Auto-reset caused by the power supply is overcome to support a more stable electric power for the hard disk driver of the dry etcher system.

Wet etching was the standard pattern transfer technique used to fabricate early generations of integrated circuits. Its widespread use arose because the technology of wet etching was well established and understood. Further, liquid etchant is available with very high selectively to both the substrate and the masking layer. However, wet etching processes are typically isotropic, which is unsuitable for many applications.
One alternative pattern transfer method that offers the capability of non-isotropic etching is dry etching. Dry etching also offers the important manufacturing advantage of eliminating the handling, consumption, and disposal of the relatively large quantities of dangerous acids and solvents used in wet etching and resist stripping processes. Dry etching and resist stripping operations use comparatively small amounts of chemicals.
The Rainbow 4520 manufactured by Lam Research Corp. is a machine that performs oxide, polysilicon, and nitride dry etching. The Rainbow 4520 is an older machine that has been in service for a number of years. One issue for the Rainbow 4520 is that through extended use, some elements of the Rainbow 4520 age and degrade. This degradation often manifests itself in the auto-resetting of the Rainbow 4520. As can be appreciated, this event will seriously adversely impact the operations of the Rainbow 4520. The auto-reset sequence causes a significant amount of down-time while the machine re-initializes, waits for temperature stabilization, and reassigns recipe parameters.
If the auto-reset occurs during a dry etch run, the conditions within the dry etch chamber will be uncontrolled, which will degrade the yield of the wafer, and furthermore, a great deal of wafers may be useless. Unfortunately, many spare parts for the Rainbow 4520 are not produced any more, which implies that repairs to those parts are now the user's responsibility. What is needed is an apparatus that prevents the auto-resetting of the Rainbow 4520.

Stabilizing apparatus for a dry etcher system

Vanguard International Semiconductor Corporation


Monitoring network link quality in a telecommunications network which includes a plurality of intermediate network elements connected to network links via which communications sessions are conducted between respective terminating devices. A communications session comprises signaling procedures relating to the control of the session and media transfer procedures for transmitting media content via a media path established using at least part of the procedures. The established media path includes media path legs which are each established between respective media path leg endpoints connected via a network link. One or more endpoints of a media path leg is determined from at least part of the procedures. The determined one or more endpoints includes a media path leg endpoint at an intermediate network element. Reporting data is generated that comprises data identifying the determined one or more endpoints. The reporting data is transmitted to an analysis system for network link quality analysis.

Methods for monitoring network link quality in a telecommunications network, in which voice calls are made, are known where Quality of Service (QoS) information for voice calls is generated in order to allow network link quality of the telecommunications network to be analyzed.
US patent application number 2006/0221942 describes identification of potential routes taken by voice calls between terminating devices in a telecommunications network by using a traceroute program to identify the potential routes. The identified potential routes taken by the voice calls can then be combined with QoS information for the voice calls in order to create a characterization of the network elements and/or call routes in the telecommunications network and allow network link quality analysis to be conducted.
U.S. Pat. No. 7,616,579 describes identification of potential routes taken by voice calls between terminating devices in a telecommunications network by using routing table information gathered from the network elements in the telecommunications network. Again, the identified potential routes taken by the voice calls can then be combined with QoS information for the voice calls in order to create a characterization of the network elements and/or call routes in the telecommunications network and allow network link quality analysis to be conducted.
Information relating to potential routes taken by voice calls between terminating devices may not provide the actual route taken by the voice calls. Therefore network link quality analysis conducted using this information may lead to false identification of problematic portions of the telecommunications network and/or omission of actual problematic portions of the telecommunications network.
It would be desirable to provide an improved system and method for monitoring network link quality in a telecommunications network.

System and method for monitoring network link quality


A microfluidic device for processing a liquid in ludci includes at least one pneumatic substrate with a pneumatic cavity and a fluidic substrate with a fluidic cavity for accommodating the liquid. The fluidic cavity is arranged opposite the pneumatic cavity. In addition, the microfluidic device has a flexible membrane which is arranged between the pneumatic substrate and the fluidic substrate. The flexible membrane is designed to fluidically separate, from one another, a fluidic chamber extending at least in part in the fluidic cavity and a pneumatic chamber extending at least in part in the pneumatic cavity. The microfluidic device further includes a first pneumatic channel for applying a first pneumatic pressure to the pneumatic chamber and a second pneumatic channel for applying a second pneumatic pressure to the pneumatic chamber.

The disclosure proceeds from a microfluidic device or a method for processing a liquid.
When processing a liquid in a microfluidic device, the flow conditions of the liquid to be processed may be of significance. To influence the flow conditions of the liquid in a microfluidic device, the microfluidic device can be shaped to promote the formation of a particular flow condition.
DE U.S. Pat. No. 9,463,460 describes various geometric embodiments of a microchannel of a microfluidic device that can promote the formation of a turbulent flow from initially two laminar flows when processing a liquid.

Microfluidic device for processing a liquid


An improved non-toxic, non-chemical, non-polluting, inexpensive electronic apparatus to control the fly population within an animal or poultry enclosure which kills by destroying the nervous system of the fly with a brief burst of high voltage oscillations that is applied to a pair of closely spaced parallel conductors every 3 to 4 seconds.

U.S. Pat. No. 5,325,624 issued to Richardson et al on Jul. 5, 1994 addressed the problems in the prior art that had limited their use and prevented them from becoming commercially acceptable products. U.S. Pat. No. 5,325,624 disclosed a non-toxic, non-chemical, non-polluting electronic apparatus to control the fly population within an animal or poultry enclosure which does not kill by electrocution or incineration but rather by destroying the nervous system of the fly with a short burst of high voltage oscillations that is applied to a pair of parallel conductors every 1 to 5 seconds. This apparatus has been sold under the name Fly Pop'R since 1992 and is presently distributed by Insect Guard Inc. of Freehold, N.J.

Electronic fly population control apparatus


Methods of treating mental disorders, including anxiety disorders such as obsessive-compulsive disorder, are provided. The methods comprise administering an effective amount of a glutamate modulator to an individual in need thereof. Also provided are methods of enhancing the activity of a serotonin reuptake inhibitor (SRI) comprising co-administering a glutamate modulator and a serotonin reuptake inhibitor. Pharmaceutical composition comprising a serotonin reuptake inhibitor and a glutamate modulator are also provided.

Anxiety disorders are often debilitating chronic conditions, which can be present from an early age or begin suddenly after a triggering event. They are prone to flare up at times of high stress. Anxiety disorders include panic disorder, agoraphobia, social anxiety disorder (also known as social phobia), specific phobia, or simple phobia, generalized anxiety disorder, obsessive-compulsive disorder, and post-traumatic stress disorder.
Many of these disorders can be treated with the aid of counseling and behavioral therapies, such as cognitive therapy. Such treatments may be used with or without adjunctive pharmaceutical therapy. A number of drugs have been used to treat these disorders, including benzodiazepines and antidepressants of all main classes: selective serotonin reuptake inhibitors ("SSRIs"), tricyclic antidepressants ("TCAs"), and monoamine oxidase inhibitors ("MAOIs").
Obsessive Compulsive Disorder ("OCD") is an example of an anxiety disorder. It is a debilitating psychiatric condition with a lifetime prevalence of 2-3%. It is characterized by recurrent, intrusive thoughts (obsessions) and/or repetitive, stereotyped behaviors (compulsions) that last for at least one hour per day and significantly interfere with an individual's normal level of functioning. Although cognitive behavioral therapy and pharmacotherapy with serotonin reuptake inhibitors (SRI) are effective treatments for many patients, a subset experience minimal relief from their symptoms with these standard treatments. When severe, OCD is completely incapacitating with devastating consequences for patients and their families. Augmentation strategies with neuroleptic medications can improve the effectiveness of SRI therapy but do not eliminate OCD symptoms (Saxena et al., J. Clin. Psychiatry, 57:303-6, 1996; McDougle et al., J. Clin. Psychiatry, 56:526-8, 1995) and are associated with adverse effects when used chronically. Consequently, improved pharmacological treatments are needed. The clinical observation that few patients experience a complete response to SRI's or dopamine antagonists suggests that other neurochemical systems are involved in the pathophysiology of OCD.
Thus, there is a need for pharmaceutical therapies that can be used to treat patients with the above disorders, including patients who do not respond to currently available therapies, as well as for pharmaceutical therapies that improve the efficacy of currently available treatment regimens.

This patent is subject to a terminal disclaimer.

Glutamate agents in the treatment of mental disorders


Method of forming a film for a semiconductor device in which a source material comprising a deuterated species is provided during formation of the film.

1. Field of the Invention
The present invention generally relates to the field of semiconductor device fabrication, and more particular, to usage of deuterated materials in semiconductor device processing.
2. Description of the Related Art
Electronic devices, such as metal oxide semiconductor (MOS) transistors, used in VSLI integrated circuits experience a number of wear out mechanisms that limit the degree to which they can be miniaturized (scaled). One of these mechanisms is the so-called hot (energetic) electron effect.
For instance, in thermally oxidized silicon, such as gate oxide formed on a silicon substrate, it is possible for electrons (or holes) generated in the silicon substrate by device action to escape from the silicon and become injected into and be trapped in the adjoining silicon oxide. Depending on the use conditions and the details of the structure of the source and drain diffusions of a MOSFET device, there will be more or fewer electrons of greater or lesser energy generated in the silicon substrate and injected into the gate oxide.
The trend in VSLI device design has been towards increased electric field (both vertical and horizontal), which aggravates hot electron effects. Among other things, the hot electron effects result in a slow, long-term change in the threshold voltage, as well as a reduction in the transconductance of MOSFET devices. Hot electron effects also can give rise to the known phenomenon of deterioration in the low-level current gain of bipolar transistors whose emitter-base junctions have been subjected to avalanche breakdown.
The accepted theory on how the hot electrons cause damage to the silicon/silicon oxide interface is that the hot electrons stimulate desorption of hydrogen from the silicon/silicon oxide interface by breaking some of the Si--H bonds present on the silicon surface, leading to an increase in interface trap density and a degradation in device performance. The hydrogen is present at the interface after being introduced into the device as result of semiconductor processes such as post-metallization anneals of wafers conducted at low temperatures in hydrogen ambient, which improve device function by passivation of crystal defects at the silicon/silicon oxide interface. The term "passivation" means that the hydrogen satisfies dangling bonds at the silicon/silicon oxide interface. However, the Si--H passivation bonds formed at the silicon/silicon oxide interface during such annealing processes are susceptible to dissociation by hot electron excitation.
It has recently been found that the hot electron effect may be mitigated by replacing deuterium (D) for hydrogen used in the passivation of the interface traps at the silicon/silicon dioxide interface. (J. W. Lyding et al., Appl. Phys. Lett. 68 (18), Apr. 29, 1996, pp. 2526-2528; and I. C. Kizilyalli et al., IEEE Electron Device Letters, vol. 18, No. 3, March 1997, pp. 81-83.) The element hydrogen has three known isotopes:
ordinary hydrogen, or protium, .sup.1.sub.1 H; heavy hydrogen, or deuterium, .sup.2.sub.1 H; and tritium, .sup.3.sub.1 H. Lyding et al. and Kizilyalli et al. teach that the deuterium isotope accumulates at the silicon/silicon dioxide interface during post-metal anneal processes, such as is done in a deuterated forming gas (D.sub.2 /N.sub.2) at a temperature of 400.degree. C. The resulting silicon-deuterium (Si--D) bonds formed at the silicon/silicon dioxide interface are found to be more resistant to dissociation from hot electron excitation stresses than a Si--H bond.
The present investigators, however, have determined that deuterium incorporated into a silicon/silicon dioxide interface for passivation by anneal processes tends to drift away from the interface as a result of subsequent thermal cycling incurred in the further processing of the semiconductor device, even where only relatively moderate temperatures, such as about 400.degree. C., are involved. In particular, the present investigators have confirmed with secondary-ion-mass spectroscopy (SIMS) data that deuterium incorporated at the silicon/silicon dioxide interface can and does migrate away from the interface during subsequent processing of the sort which effectively "anneals" the wafer as the intended objective or as an incidental effect of a different process, such as film deposition. Therefore, any potential performance enhancements imparted by the deuterium anneal of the prior art were evanescent in nature based on what the present investigators have determined. For purposes of this application, the term "anneals", and variants thereof, means subjecting a semiconductor wafer to at least one thermal cycle in which it is heated and thereafter cooled.
Therefore, problems remained unresolved in the prior art with respect to semiconductor processing involving hydrogen-containing reactants and ambients which tended to cause silicon/silicon dioxide interface disruption.

Use of deuterated materials in semiconductor processing

International Business Machines Corporation


A non-volatile memory device having a SONOS structure and a manufacturing method thereof, where a conductive layer is formed between a charge trap layer and a blocking insulation layer of the SONOS structure. Therefore, when a voltage is applied to a gate, the conductive layer undergoes voltage distributions. Accordingly, a desired voltage can be applied to the blocking insulation layer, the charge trap layer and the tunnel insulating layer by controlling the effective oxide thickness (EOT) of the blocking insulation layer and the EOT of the charge trap layer and the tunnel insulating layer. It is therefore possible to improve the erase speed of a cell.

The invention relates, in general, to a non-volatile memory device and, more particularly, to a non-volatile memory device having a Polysilicon Oxide Nitride Oxide Semiconductor (SONOS) structure with an improved erase speed, and a manufacturing method thereof.
Nonvolatile Semiconductor Memories (NVSM) are largely classified into floating gate series and Metal Insulator Semiconductor (MIS) series in which two or more kinds of dielectric layers are laminated doubly or triply in terms of the process technology.
The floating gate series implements a memory characteristic by employing a potential well. A representative example of the floating gate series is an EPROM Tunnel Oxide (ETO) structure that has been widely used as flash Electrically Erasable Programmable Read Only Memory (EEPROM). The MIS series performs a memory function by employing traps existing at the dielectric layer bulk, the dielectric layer—the dielectric layer interface, and the dielectric layer—semiconductor interface. A representative example of the MIS series is a Metal/Polysilicon Oxide Nitride Oxide Semiconductor (MONOS/SONOS) that has been widely used as flash EEPROM.
A difference between the SONOS and general flash memory is that in the general flash memory, charges are stored in the floating gate, whereas in the SONOS, charges are stored in the nitride layer in terms of the structure.
Furthermore, in the general flash memory, the floating gate is formed using polysilicon. Thus, if any one defect exists in polysilicon, the retention time of charge is significantly lowered. In contrast, in the SONOS, the nitride layer is used instead of polysilicon as described above. Accordingly, the sensitivity to defect in process is relatively small.
In addition, in the flash memory, tunnel oxide having a thickness of about 70 Å is formed under the floating gate. There is a limit to the implementation of a low-voltage and high-speed operation. However, in the SONOS, direct tunneling oxide is formed under the nitride layer. It is therefore possible to implement a memory device having a lower voltage, lower power and high-speed operation.
A conventional flash memory device having a SONOS structure described below with reference to FIG. 1.
Referring to FIG. 1, a tunnel oxide layer 11, a nitride layer 12, a blocking oxide layer 13, a polysilicon layer 14, and a gate electrode 15 are sequentially formed over a semiconductor substrate 10. Word line patterns are then formed by an etch process.
In the flash memory device having a the SONOS structure, a different electric field (E-field) cannot be applied to an insulating layer because the same E-field cannot be applied to the whole complex layer of the blocking oxide layer 13 (i.e., an insulating layer), the nitride layer 12 (for storing charges) and the tunnel oxide layer 11.
In this case, if a voltage is applied to the gate electrode 15 so as to erase charges stored in the nitride layer 12, the charges stored in the nitride layer 12 are moved to the semiconductor substrate 10 by a Fowler-Nordheim (F-N) tunneling current through the tunnel oxide layer 11 and are then erased. However, since the same E-field is applied to the blocking oxide layer 13 over the nitride layer 12, the charges are moved from the gate electrode 15 to the nitride layer 12 through the blocking oxide layer 13 and are then programmed again, so that the erase speed is slowed.
To prevent the charges from being injected from the gate electrode 15 at the time of the erase operation, a material having a high work function is used in the gate electrode 15. However, this method is limited in terms of its improvement of the erase speed.