A method and system for physiological gating is disclosed. A method and system for detecting and predictably estimating regular cycles of physiological activity or movements is disclosed. Another disclosed aspect of the invention is directed to predictive actuation of gating system components. Yet another disclosed aspect of the invention is directed to physiological gating of radiation treatment based upon the phase of the physiological activity. Gating can be performed, either prospectively or retrospectively, to any type of procedure, including radiation therapy or imaging, or other types of medical devices and procedures such as PET, MRI, SPECT, and CT scans.

The present invention relates to medical methods and systems. More particularly, the invention relates to a method and system for physiological gating.
Many types of medical procedures involve devices and machines that act upon a particular portion of a patient body. For example, radiation therapy involves medical procedures that selectively expose certain areas of a human body, such as cancerous tumors, to high doses of radiation. The intent of the radiation therapy is to irradiate the targeted biological tissue such that the harmful tissue is destroyed. In certain types of radiotherapy, the irradiation volume can be restricted to the size and shape of the tumor or targeted tissue region to avoid inflicting unnecessary radiation damage to healthy tissue. Conformal therapy is a radiotherapy technique that is often employed to optimize dose distribution by conforming the treatment volume more closely to the targeted tumor.
Other medical procedure are also directed to specific portions of a patient body. For example, radiation imaging typically directs radiation only to the portion of a patient body to be imaged. 3-dimensional imaging applications such as computed topography (CT), positron emission tomography (PET), and magnetic resonance imaging (MRI) scans also are directed to specific portions of a patient body.
Normal physiological movement represents a limitation in the clinical planning and delivery of medical procedures to a patient body. Normal physiological movement, such as respiration or heart movement, can cause a positional movement of the body portion undergoing treatment, measurement, or imaging. With respect to radiation therapy, if the radiation beam has been shaped to conform the treatment volume to the exact dimensions of a tumor, then movement of that tumor during treatment could result in the radiation beam not being sufficiently sized or shaped to fully cover the targeted tumoral tissue. For imaging applications, normal physiological movement could result in blurred images or image artifacts.
One approach to this problem involves physiological gating of the medical procedure, such as gating of a radiation beam during treatment, with the gating signal synchronized to the movement of the patient's body. In this approach, instruments are utilized to measure the physiological state and/or movement of the patient. Respiration has been shown to cause movements in the position of a lung tumor in a patient's body; if radiotherapy is being applied to the lung tumor, then a temperature sensor, strain gauge, preumotactrograph, or optical imaging system can be utilized to measure the patient during a respiration cycle. These instruments can produce a signal indicative of the movement of the patient during the respiratory cycle. The radiation beam can be gated based upon certain threshold amplitude levels of the measured respiratory signal, such that the radiation beam is disengaged or stopped during particular time points in the respiration signal that correspond to excessive movement of the lung tumor.
Many approaches to physiological gating are reactive, that is, these approaches utilize gating methods that slavishly react to measured levels of physiological movements. One drawback to reactive gating systems is that the measured physiological movement may involve motion that that is relatively fast when compared to reaction time of the imaging or therapy device that is being gated. Thus, a purely reactive gating system may not be able to react fast enough to effectively gate the applied radiation. For example, the gating system may include a switch or trigger for gating radiation which requires a given time period Δt to fully activate. If the delay period Δt is relatively long compared to the measured physiological motion cycle, then a system employing such a trigger in a reactive manner may not be able to effectively gate the radiation at appropriate time points to minimize the effect of motion.
Therefore, there is a need for a system and method to address these and other problems of the related art. There is a need for a method and system for physiological gating which is not purely reactive to measure physiological movement signals.
The present invention provides an improved method and system for physiological gating. According to one embodiment, gating is performed based upon visual detection of patient motion relating to physiological activity. In an embodiment, an optical-based system is employed to measure and record physiological patient movement, in which a camera tracks and views the movement of a marker block or marker(s). A method and system is also disclosed for detecting and predictably estimating regular cycles of physiological activity or movements. Another aspect of an embodiment of the invention is directed to predictive actuation of gating system components. Yet another aspect of the invention is directed to physiological gating based upon the phase or non-periodicity of the physiological activity. The present invention can also be used to gate, either prospectively or retrospectively, any type of procedure, including radiation therapy or imaging, other types of medical devices and procedures such as MRI, PET, SPECT, and CT scans.
An embodiment of the invention also provides a system and method for position and motion monitoring including prompting the patient to hold breath and monitoring of the breath-hold state of the patient. In one embodiment, a patient positioning system comprises at least one camera, a marker block, and a computing device to compute the location and orientation of the marker block. The marker block preferably comprises a plurality of landmarks, e.g., retro-reflective markers. According to an embodiment, a method for identifying the position of a patient comprises the steps of first co-locating the marker block with a patient, viewing the marker block with at least one camera, producing image coordinates for the identified landmarks viewed by the camera, comparing the image coordinates with reference coordinates for the landmarks, and thereafter determining the position and orientation of the patient.
Consistent patient positioning, either within the same device for different sessions, or between multiple devices, is facilitated using an optical-based positioning system, according to one embodiment of the present invention. Within the same device, the positioning system provides absolute position information for the patient that can be re-created during each treatment session. Between multiple devices, the optical-based positioning system establishes relative positioning information for the patient. The relative positioning information can be used to correctly conform the position of the patient between multiple devices. In one embodiment, a patient undergoes treatment planning at a first device during which an optical positioning system identifies a first relative position for the patient. Thereafter, the patient is controllably positioned to a therapy device, e.g., using a movable treatment table or in which the patient remains stationary but either the treatment planning or therapy device are moved in relation to the patient, e.g., on rails. The relative position of the patient to the therapy device is established and manipulated to conform to the desired treatment strategy.
The present invention also provides a novel method and mechanism for implementing a physiological monitor, such as a respiration monitor. In one embodiment, a physiological monitor is implemented using an optical-based system in which a video camera records body movement relating to the physiological activity being monitored. The image data relating to the body movement is processed and displayed to represent the physiological movement. The movement data can be analyzed and viewed to monitor the physiological activity.
User interface inventions are disclosed for controlling and displaying motion, positioning, and gating information. In one embodiment, a circular interface is provides to control gating or treatment intervals based upon phase of physiological movement. Interface embodiments of the invention provide display and control for enabling/disabling gating and establishing gating thresholds. Additional interface embodiments display breath hold parameters and physiological motion range information.
One embodiment of the invention provides a method and mechanism for video and/or audio prompting of patients to maintain desired physiological movement patterns. A disclosed embodiment employs a slider image that simultaneously displays visual feedback of the physiological movement as well as a desired range of the movement. For respiration activity, the slider comprises a movable slider bar that moves in response to a patient's inhale-exhale movements. This provides visual prompting and feedback regarding the respiration activity. In an embodiment, verbal prompting are employed to assist in controlling, maintaining, or manipulating the physiological activity of interest. For respiration activity, such verbal promptings could be computer-activated prompting to instruct a patient to breath in and breath out.
These and other aspects, objects, and advantages of the invention are described below in the detailed description, drawings, and claims.

Method and system for predictive physiological gating


In an elevator rope, a plurality of steel outer layer strands are twisted together on an outer circumference of an inner layer rope. The inner layer rope has: a fiber core; a plurality of steel inner layer strands that are twisted together directly onto an outer circumference of the fiber core; and a resin inner layer rope coating body that is coated onto the outer circumference. A diameter of the inner layer strands is smaller than a diameter of the outer layer strands. The inner layer strands are greater in number than the outer layer strands.

In conventional elevator ropes, a core rope is disposed centrally. The core rope is configured by twisting three core rope strands together with each other. Each of the core rope strands is constituted by a number of yarns that are formed by bundling fibers. An outer circumference of the core rope is coated by a resin core rope coating body. A plurality of steel strands are twisted together on an outer circumference of the core rope coating body. Each of the steel strands is formed by twisting together a plurality of steel wires (see Patent Literature 1, for example).


Disclosed are a membrane-electrode assembly for fuel cells having improved durability and a manufacturing method thereof. Hydrogen peroxide, from which a hydroxyl radical is generated, may be removed using an antioxidant having the structure A1-aA′aBO3-δ and including strontium or samarium, thereby improving the durability of an electrolyte membrane and an electrode.

Polymer electrolyte membrane fuel cells are devices that generate electricity using an electrochemical reaction between hydrogen and oxygen in the air, and are well-known as environmentally friendly next-generation energy sources that have high electricity-generation efficiency and emit almost no exhaust materials except for water. In addition, polymer electrolyte membrane fuel cells generally operate at a temperature of about 95° C. or less, and have high power density.
The reaction for electricity production by fuel cells occurs in a membrane-electrode assembly (MEA), which includes a perfluorinated sulfonic acid ionomer-based membrane and a pair of electrodes (e.g., an anode and a cathode). Hydrogen supplied to an anode, which is an oxidation electrode for fuel cells, is split into a proton and an electron. The proton is moved through the membrane to a reduction electrode, i.e. a cathode, and the electron is moved to the cathode via an exterior circuit. At the cathode, an oxygen molecule, the proton, and the electron react together to produce electricity and heat, and at the same time, water (H2O) as a by-product.
In general, hydrogen and oxygen in the air, which are reaction gases for fuel cells, cross over through the electrolyte membrane to facilitate the production of hydrogen peroxide (HOOH). The hydrogen peroxide produces oxygen-containing radicals such as a hydroxyl radical (.OH) and a hydroperoxyl radical (.OOH). These radicals attack the perfluorinated sulfonic acid-based electrolyte membrane, inducing the chemical degradation of the membrane, which ultimately has the negative consequence of reducing the durability of fuel cells.
In the related arts, a representative catalyst for dissolving hydrogen peroxide through the following reaction, e.g. manganese dioxide (MnO2), has been used. Manganese dioxide may have substantial antioxidation activity but still may be insufficient to prevent the chemical degradation of the perfluorinated sulfonic acid-based electrolyte membrane.MnO2+H2O2+2H+→Mn2++2H2O+O2 Mn2++2H2O2H↔Mn(OH)2+2H+Mn(OH)2+H2O2→MnO2+2H2O(Total reaction: 2H2O2→2H2O+O2)
Further, in the related arts, a primary antioxidant for removing a hydroxyl radical, such as ceria (CeO2, cerium oxide), zirconia (ZrO2, zirconium oxide), or ceria-zirconia, has been used to prevent the chemical degradation of the electrolyte membrane. Since hydrogen peroxide is an elementary material, however, the function of an antioxidant for removing only a hydroxyl radical may be limited.
The above information disclosed in this Background section is provided only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

Membrane-electrode assembly for fuel cells having improved durability and manufacturing method thereof


A solid-state image pickup element comprises: a semiconductor substrate; an imaging section comprising a photoelectric converting portion, formed on the semiconductor substrate; an intralayer lens formed in an upper layer of the imaging section; and a peripheral circuit section that processes an output of the imaging section, formed on the semiconductor substrate, wherein at least part of the intralayer lens is formed in a lower layer of a wiring portion in the peripheral circuit section.

1. Field of the Invention
The present invention relates to a solid-state image pickup element and a method of producing it, and more particularly to formation of an intralayer lens.
2. Description of the Related Art
Recently, in solid-state image pickup elements, increase of the number of imaging pixels is advanced to the level of gigapixels or more, and miniaturization of an element is going on progressing. Under such circumstances, the sensitivity is requested to be improved. However, an on-chip lens which is formed on a color filter and in the uppermost layer is not sufficient for improving the sensitivity. A technique has been proposed in which a lens (intralayer lens) is further formed between an on-chip lens and a sensor portion, thereby enhancing the light converging function. As an example of such an intralayer lens, there is a convex superior portion which is formed on a face planarized by filling a step caused by a transfer electrode or the like, and in which the surface side is formed as a convex face.
As an example of a method of producing such a convex superior portion, there is a method in which a stacked layer of a film of a lens material for the convex superior portion and a resist is dry etched. In the method, a film of the lens material is deposited, the resist on the film is patterned into a shape of the lens, and the lens shape of the resist is transferred to the lens material film by dry etching.
Another method of enhancing the sensitivity by adjusting the focal length of a lens to a desired length in a wide range has been proposed (JP-A-2000-164837).
In this method, a resist mask having a shape of a lens is formed on a layer of a material for an intralayer lens, the lens shape of the resist mask is transferred to the layer of the intralayer lens material by the etch back method, thereby forming an intralayer lens, and the focal length is adjusted by the etch back amount.
When an intralayer lens is disposed below an on-chip lens formed by a microlens as described above, incident light is converged in two steps to enable a larger amount of light to enter a light receiving portion. The sensitivity of a solid-state image pickup element can be enhanced as compared with the case where only an on-chip lens is formed.
In this way, the height of an intralayer lens of a solid-state image pickup element can adjust the focal length by means of controlling the etch back amount. The intralayer lens is formed by a method which is performed after formation of metal wiring, and in which the lens material is used also as a wiring protective film (passivation film). In a step of forming the lens, when the lens thickness is reduced in the process of etching back the lens material, also the passivation film for a wiring portion is thinned, and the wiring portion may be exposed. Therefore, the film thickness has limitations, and reduction of the height of the intralayer lens is restricted. Also when the lens material is not used also as the wiring protective film, the irregularity of the surface of the wiring portion may cause the accuracy of a step of patterning the lens or the like to be reduced.

Solid-state image pickup element and method of producing the same


There is provided an axial piston device that includes a housing, a rotary shaft, a cylinder block, and a piston. The housing includes a housing body opened at a first end thereof and a plate disposed at the first end of the housing body. The rotary shaft is rotatably supported about an axis by the housing body and the plate. The cylinder block is rotated together with the rotary shaft and is accommodated inside the housing. The piston is accommodated in the cylinder block in slidable a manner in an axial direction. Furthermore, the plate is provided with a pair of first oil passages having first ends communicating with a discharge port and a suction port of the cylinder block and second ends opened to the surface of the plate, and a drain oil passage for allowing at least one of the first oil passages to communicate with an oil sump. The drain oil passage is provided with a rotary valve which can selectively switch a shutoff position at which the drain oil passage is shut off and a communication position at which the drain oil passage is communicated.

1. Field of the Invention
The present invention relates to an axial piston device such as a pump unit or a motor unit.
2. Related Art
An axial piston device comprising a cylinder block rotated about an axis and a piston accommodated in a slidable manner in an axial direction with respect to the cylinder block while being rotated about the axis together with the cylinder block has been widely utilized as a pump unit to be used as a hydraulic source with respect to hydraulic equipment such as a hydraulic motor or as a motor unit to be hydraulically driven by a hydraulic source such as a hydraulic pump.
Hereinafter, description will be given of a conventional axial piston device by way of a pump unit.
A conventional pump unit comprises, for example, a housing which has a housing body opened at a first end thereof and a plate attached to the first end of the housing body, a pump shaft which is supported by the housing and is driven by a drive source, and a pump body which is accommodated inside the housing and is rotatably driven by the pump shaft, wherein each of a discharge port and a suction port of the pump body is hydraulically connected in circulation to a corresponding hydraulic device such as a hydraulic motor.
That is to say, a pair of oil passages communicating with the discharge port and the suction port of the pump body, respectively, is formed at the plate. Thus, pressurized oil is supplied from the pump body to the hydraulic device via one of the oil passages, and further, return oil is returned to the pump body from the hydraulic device via the other one of the oil passages.
In the pump unit after assembly, air is mixed inside the pair of oil passages; therefore, the pair of oil passages is required to be deaerated.
In other words, the pump unit and the hydraulic device are connected via the pair of oil passages, thereby forming a circulation circuit, wherein the circulation circuit is required to be sufficiently deaerated upon filling oil into the circulation circuit.
In regard to this point, in the conventional pump unit, a drain oil passage for allowing the pair of oil passages to communicate with an oil sump is formed at the plate, and further, a shutoff valve is disposed inside the drain oil passage in such a manner as to be positionally adjusted in an axial direction (see U.S. Pat. No. 6,332,393).
In particular, a valve seat is provided at the drain oil passage. The position of the shutoff valve in the axial direction can be adjusted in such a manner that the shutoff valve can take a shutoff position at which the shutoff valve is in contact with the valve seat so as to have the drain oil passage shut off and a communication position at which the shutoff valve is apart from the valve seat in the axial direction so as to have the drain oil passage communicated.
In this conventional pump unit, the pair of oil passages can communicate with or can be cut out of the oil sump by operating the shutoff valve, with an attendant problem of impossibility of speedy switching between the communication and shutoff.
Namely, in the conventional pump unit, the position of the shutoff valve in the axial direction can be adjusted with respect to the plate owing to screw connection. Consequently, in order to move the shutoff valve from the shutoff position to the communication position at which a sufficient opening width is secured, the shutoff valve must be rotated on an axis many times.
The present invention has been accomplished in view of the above prior art. Therefore, a primary object of the present invention is to provide an axial piston device in which an oil passage can be securely and speedily deaerated.


A method of processing food elements of plant tissue having a cellular structure with substantial starch content comprising arranging the food elements in an aqueous liquid and applying acoustic energy with a selected frequency energy and time profile to modify the cellular structure of a surface portion of the food elements by removing components from the cellular structure and establishing a pectin based surface portion surrounding a core portion and adapted to act as a barrier in a high temperature subsequent cooking process, the modified cellular structure providing for a relatively low moisture surface portion to be established and maintained and moisture to be substantially retained in the core portion after subsequent cooking processes.

Partially processed or fully processed food products are derived from various raw foodstuffs and customers, including domestic consumers and restaurants, welcome the provision of such processed food in a form which can be quickly readied for presentation to the ultimate consumer, often with a brief heating or food processing step. For example, outlets wishing to serve french-fries can have the convenience of purchasing bulk packs of frozen vegetable which can be brought to a predictable and attractive form by a brief period of cooking either with a deep frying technique or an oven technique.
Thus, there is a major demand in the market of many countries for products such as french-fried potato chips produced by cutting the potatoes into elongate square cross-sectional chips which are deep fried to produce chips to produce an appetising hot product. The product desirably has an attractive coloured exterior with a crunchy shell and a soft mealy interior. Thus, there is a major market for frozen, partially pre-fried potato chips (known as par-fried potatoes), and this approach simplifies storage and inventory control to outlets while assuring uniform quality between batches. Time and delay at an outlet and avoiding what would otherwise be considerable labour costs in processing french-fries from raw potatoes is achieved.
A typical process for producing a 10 mm frozen french-fry is as follows:                (a) Potatoes are firstly washed and then sometimes graded for quality and size for different product runs.        (b) The potatoes are peeled typically by a steam process with steam at high pressure and high temperature of around 200° C. for around 14 seconds.        (c) The potatoes are cut into elongate strips e.g. square cross-section of around 10 mm sides, conveniently in a water knife cutting or similar process.        (d) The potato strips are further processed to remove the defective strips and eyes, and then washed.        (e) Potato strips are blanched in a hot water process with this step reducing excess free sugars from the surface of the strips and to transform enzymes so as to be inactive. Sometimes the blanch is in two stages, namely a high temperature strep of around 83° C. for a few minutes followed a low temperature step typically around 73° C. for often a longer period.        (f) A drying process is effected to reduce the water content of the blanched strips. A weight loss of around 12% typically occurs where the drying process is around 60° C.        (g) Par-frying of the potato chips is effected in hot oil at around 190° C. for a suitable time of around 50 seconds.        (h) Lastly freezing is effected to freeze the potato chips down to a temperature of around −18° C. ready for packing, and for storage and distribution.
Frozen potato chips produced as described above typically will be suitable to be finish fried at a serving location in suitable oil at about 180° C. for around 3 minutes. It is recognised that such hot chips need to be produced at an outlet in batches, but the holding time post-frying is short and therefore smaller, more frequent batches of chips need to be prepared and in many instances chips are discarded because they have texturally decayed. Such hot chips are liable to become gradually limp when holding due to migration of moisture from the product interior to the surface.
Apart from a long-standing desirability where possible to provide for economic processing and possibly improving consumer appeal and satisfaction for final product, it is has also been long recognised there is significant absorption of cooking oils into starch products such as french-fries which are cooked by frying. Adverse health implications are well understood to exist with foods with relative high fat levels and, at least for french-fries, the well established processes have an inevitable high fat content in the final product.
Despite the characteristics of present food processing, the processing of starch foods such as potatoes into products such as french-fries has essentially remained an industry with little change over an extended period.
Broadly, the present invention is concerned with devising different processes for starch-based foods which offer the potential for distinct and useful changes to methods, apparatus and/or products in the food industry.


A device and method for reducing wear and stress in the string of a stringed instrument, such as a guitar. Certain stringed instruments are strung by advancing strings through string apertures in the body of the instrument. The device includes tubular sleeves that are placed into the string apertures. As the instrument is strung, the strings of the instrument are tightened. When tightened, the strings abut against and bend around the tubular sleeve. The tubular sleeve has a curved surface against which the strings bend. This lowers stress concentrations in the strings at the points of the bend. Furthermore, the tubular sleeves are made from a material that is softer than the material of the instrument's strings. Accordingly, as the instrument's strings wear against the sleeves, the sleeves experience the wear more so than the strings.

1. Field of the Invention
In general, the present invention relates to instrument strings of the type that are most commonly used on modern electric guitars. More particularly, the present invention relates to guides that are used in conjunction with guitar strings to help the guitar strings resist breakage during use.
2. Description of the Prior Art
Hand strummed stringed instruments have been in existence for many centuries. During that period of time, such stringed instruments have evolved into many different forms. One of those forms came is the acoustical guitar. Acoustical guitars have a hollow body and a neck that extends from the body. A plurality of strings are strung from the neck across an opening in the body. As the strings are strummed, the vibration of the string resonates in the hollow body of the guitar, thus amplifying the sound of the string.
In an acoustic guitar, the strings are attached to the top of the neck with tuning pegs or geared tuning mechanisms. These devices are used to adjust the tension in the guitar strings. At the opposite end of the guitar strings, the strings attach to a saddle block that firmly anchors the guitar strings in place.
In the middle of the twentieth century, the design of guitars again evolved, thereby introducing the electric guitar. Originally, electric guitars where merely acoustical guitars with an acoustical transducer placed within the hollow body of the guitar. The acoustical transducer was connected to an electrical amplifier and a speaker that reproduced the sound of the guitar.
As electrical guitar designs matured, the entire design of the guitar was designed around its electrical components. In modern electrical guitar designs, the body of the guitar is no longer hollow. Rather the body of the guitar is solid. Positioned below the stings is now an electrical pick-up. The electrical pick-up directly converts the vibrations of the guitar strings into corresponding electrical signals that can be amplified, altered and broadcast by other electronic devices.
Along with the advent of the solid guitar body came a new way to mount guitar strings to the guitar body. Many modern electrical guitars have apertures formed through the solid body. The apertures have a diameter just wide enough to enable the passage of a guitar string through the aperture. Specialized guitar strings are produced for use with such electric guitars. The specialized strings terminate at one end with enlarged end caps. Such strings are shown in U.S. Pat. No. 5,913,257 to Schaller, entitled Method Of Manufacturing Guitar Strings And Guitar Strings Resulting From Such Method. The strings can pass through the apertures in the guitar, but the end caps cannot. As such, by threading such a specialized guitar string through an aperture in the guitar body, the guitar string becomes firmly anchored in place.
Electric guitar strings are passed from the rear of the guitar body toward the front of the guitar body. As the strings pass through the guitar body, the guitar strings fold over a bridge assembly before extending across the guitar body and up to the neck of the guitar. The bridge assembly in an electric guitar typically contains metal saddles. The guitar strings abut and bend against the saddles as the guitar strings turn toward the neck of the guitar.
As the guitar is played, the strings vibrate. Some of this vibration is experienced at the interface between the guitar strings and the saddles in the bridge assembly. As the guitar strings vibrate, the strings wear against the saddle. Furthermore, the point of contact against the saddle is a stress concentration point for the guitar strings. Eventually, the guitar strings wear to a point where the stress on the string causes them to break. The break on the string is typically right at the point where the string contacts the saddle.
In the prior art, there have been different techniques used that are intended to help a guitar string resist breakage. One technique is to reinforce the guitar string at the point where the guitar string contacts the saddle in the bridge assembly. Such prior art techniques are exemplified by U.S. Pat. No. 4,581,976 to Ball, entitled Reinforced Musical Instrument String. This technique works, however, the reinforcements add significantly to the cost of the guitar strings.
Another technique used to reduce guitar string breakage, is to increase the curvature of the saddle at the point where the string abuts the saddle. Such prior art techniques are exemplified by U.S. Pat. No. 4,960,027 to Dunwoodle, entitled Bridge For A Stringed Instrument. Such devices do reduce the number of guitar string breakages. However, the guitar string still does wear against a metal saddle and does eventually wear to a point of breakage.
Recognizing that wear is caused by the contact of the metal guitar string against the metal saddle, pads have been developed that are intended to be placed between the string and the saddle. Such prior art pads are exemplified by U.S. Pat. No. 5,465,643, entitled Guitar String Support. The problem associated with such pads is that they are very difficult to correctly position between the guitar string and the saddle. Furthermore, the pad conforms to the shape of the saddle, thus the guitar string still wears against a salient point. This often causes the pad to prematurely wear away. This effects the protection provided to the guitar strings by the pads and the tuning of the guitar strings.
A need therefore exists for a device that can prevent wear between a guitar string and a saddle of a bridge assembly, yet is easy to install and is inexpensive. This need is provided by the present invention as described and claimed below.

Protective sleeve for an instrument string and its method of application to an instrument


The present invention discloses a flexible connecting structure of a prefabricated component and a building main body. The flexible connecting structure comprises multiple layers of cast-in-situ building main bodies spaced up and down, a prefabricated component is connected between two adjacent cast-in-situ building main bodies, a tenon is provided at the lower end of the prefabricated component, a mortise matching the tenon is provided on the top surface of the cast-in-situ building main body, and the prefabricated component is socketed to the lower layer of cast-in-situ building main body by tenon-and-mortise cooperation; and a first flexible layer for reducing the connection rigidity between the prefabricated component and the upper layer of cast-in-situ building main body is provided at the junction between the prefabricated component and the upper layer of cast-in-situ building main body. The present invention realizes a flexible connection between a prefabricated component and a building main body, and avoids the influence of the prefabricated component on the rigidity of the building main body.

Assembly-type components have the characteristics of standardized design, factory production, assembly-type construction, energy saving and consumption reduction, environmental protection, short construction period, improved quality and the like, and can promote deep integration of informatization and industrialization. Therefore, assembly-type buildings have been vigorously developed and applied. Prefabricated toilets or prefabricated kitchens can achieve standardized design, factory production and assembly-type construction, have the advantages of integrity, good quality and the like, and assembly-type prefabricated toilets or prefabricated kitchens are used as integral prefabricated units in assembly-type buildings.
At present, there are two types of connection methods for assembly-type nodes: wet connection and dry connection. The wet connection includes grout anchor connection, ordinary post-cast integral connection, ordinary cast-in-situ connection, grout assembly, reinforced sleeve grouting connection, etc. The dry connection includes mechanical sleeve connection, pre-stressed crimp connection, corbel connection, welding connection, bolt connection, etc. The wet connection is good in integrity but inconvenient in construction, for example, there has no effective method for inspecting the quality of reinforced sleeve grouting connection at present. Compared with the wet connection, the existing dry connection has the characteristic of convenient construction, but is still relatively complicated, and requires corresponding operations such as tightening, tensioning and welding. Because the prefabricated toilet or prefabricated kitchen is connected between the upper and lower layers of building main bodies, and the overall rigidity of the prefabricated toilet or prefabricated kitchen is high, if no effective measures are taken to avoid the influence of the prefabricated toilet or prefabricated kitchen on the rigidity of the building main body, the rigidity of the original building design will be increased in the vertical and horizontal areas of prefabricated components, which produces an adverse effect on the earthquake resistance of the building.

Flexible connecting structure of prefabricated component and building main body

HUNAN CONSTRUCTION ENGINEERING GROUP CO., LTD.

HUNAN CONSTRUCTION TECHNOLOGY RESEARCH INSTITUTE


A semiconductor device comprises a vertical MIS-SIT which has a smaller source-to-drain distance for operation at ultra-high speed. The semiconductor device has a substrate crystal for epitaxial growth thereon, least two semiconductor regions of different conductivity types deposited by way of epitaxial growth on the substrate crystal according to either metal organic chemical vapor deposition (MO-CVD) or molecular layer epitaxy (MLE), thereby providing a source-drain structure, a gate side formed by etching the semiconductor regions of the source-drain structure, the gate side comprising either a (111)A face or a (111)B face, and a semiconductor region deposited as a gate by way of epitaxial growth on the gate side according to either MO-CVD or MLE.

1. Field of the Invention
The present invention relates to a semiconductor device comprising a high-speed static induction transistor, and a method of manufacturing such a semiconductor device.
2. Description of the Prior Art
Known field-effect transistors include junction and MIS (Metal Insulator Semiconductor) field-effect transistors. The junction and MIS field-effect transistors exhibit saturated current vs. voltage characteristics in which the drain current is gradually saturated as the drain voltage increases.
Static induction field-effect transistors (hereinafter also referred to as "SIT") whose drain current continues to increase as the drain voltage increases are disclosed in Japanese patent publication No. 52-6076 entitled "Field-effect transistor" and Japanese patent publication No. 52-17720 entitled "Field-effect transistor."
The SITs are better than field-effect transistors (hereinafter also referred to as "FET") as they are characterized by a large power-handling capability, a high dielectric strength, a large current-handling capacity, a low distortion, a low noise level, low power consumption, and high-speed operation. The SITs are also much better than conventional bipolar transistors and FETs with respect to temperature characteristics.
Since the SITs have proven highly satisfactory as discrete elements and IC components, they are finding growing use in various new applications.
In the case where a logic gate is to be constructed of SITs, normally-off SITs which do not pass a current when no bias is applied to their gates are suitable for use as such logic gate elements. Normally-off SITs with pn-junction gates undergo the injection of minority carriers as the gates are successively biased. Accumulation of such minority carriers makes the normally-off SITs difficult to operate at high speed.

Method of manufacturing a static induction field-effect transistor


A bending machine for closing channels which simultaneously bends both side walls of a "U" shaped metal channel, comprising: a support frame; a lower male member slide mounted on the support frame, having a normally closed two-halves male member, each half having a notch in lateral wall thereof, and is associated with driving means for opening the halves of the male member when receiving a channel and for releasing the channel once its side walls thereof have been bent inside each notch, allowing to remove it therefrom; and two lateral bending inserts each slide mounted on the support frame, and associated with driving means, for bending both side walls of the channel into the notches. If desired an upper member, mounted on lowering and lifting means, is provided, having a blank holder to retain a channel on the lower male member when it is closed and/or a die member for simultaneously bend a plate forming a channel, and then close both side walls thereof forming a closed channel.

A. Field of the Invention
The present invention relates to bending machines and more particularly to a channel bending machine which simultaneously bends both side walls of a "U" shaped metal channel.
B. Description of the Related Art
There is a number of well known bending machines for metal pieces such as wires, plates, etc., of the type wherein the metal piece is firstly bent by pressing such piece by means of a pressing member against a support member having a predetermined pattern.
With this type of machines a great variety of metal pieces can be manufactured, including channel shaped pieces of the type wherein a large metal plate is bent by its longitudinal edges usually at about 90.degree., which are used for multiple purposes such as in the automotive industry for the manufacturing of truck chassis or automotive chassis.
Sometimes, for some specific applications, the channel shaped piece have to be additionally bent by one or both side walls of the channel in order to give them for example a special "closed" channel shape, which is very difficult to carry out with the actual machines, because of the fact that the piece is already formed as a channel and is very difficult to adapt it at the actual components of the machines, firstly by one side and then by the other side.
One bending machine for forming "U" pieces such as rounded bars, channels, sections and the like, is disclosed in US. Pat. Nos. 4,798,073 and 4,890,469 both of Dischler, which comprises two opposed spaced bending devices, each including at least two bending components and drive means to move at least one of the bending components essentially transversely to the length of the piece to be bend.
To produce a rounded "U" shaped piece, the piece to be bent is placed between the bending components of each of the bending devices and then, a bending moment is applied by the bending components of two of the bending devices, acting transversely to the longitudinal axis of the piece. Due to the application of such bending torque the piece is bent in a rounded "U" shape piece.
Such machine, cannot produce pieces with side walls at 90.degree. and it is not possible to close the sides of the rounded "U" shaped piece or a channel in the same machine.
In the known art, although highly desirable, there is no machine which simultaneously could bend the plate as a "U" shaped channel, and then close the side walls thereof, mainly because there were no components to close the sides of the "U" shaped channel and there was no possibility to remove the closed channel from the support parts of the machine.
In other words, there is no machine available which be capable of simultaneously bend a metal plate as a "U" shaped channel, and then close one or both side walls thereof in a single machine in a single operation, mainly because there was no possibility to remove a closed channel from a support piece of the machine.
Considering the above referred problems, applicants developed a bending machine which simultaneously can bend both side walls of a "U" shaped channel to close one or the two side walls thereof, comprising: a support frame; a lower male member slide mounted on the support frame, having a two-halves male member, each half having a notch in lateral wall thereof, and is associated with driving means for opening the normally closed two halves of the male member when receiving a channel and releasing the channel once its side walls thereof have been closed inside each notch, allowing to remove it therefrom; and two lateral bending inserts each slide mounted on the support frame, and associated with driving means, for bending both side walls the channel into the notches. If desired an upper member, mounted on lowering and lifting means, is provided, having a blank holder to retain a channel on the lower male member when it is closed and/or a die member for simultaneously bend a plate forming a channel, and then close both side walls thereof forming a closed channel.
The bending machine of the present invention also can be combined with a channel forming machine in order to form a channel and then bending the sides of the channel.


Crosslinked membranes for anion exchange applications, and methods of making and using the same, are described.

Most known anion exchange membranes involve custom polymer synthesis in very small batches (such as less than 10 g or 1 g), where scale-up of syntheses can take years to reach kilogram scale. This is slow and costly. Known anion exchange membranes also commonly suffer from limited processability, the use of potentially hazardous organic solvents, mechanically weak or poor durability, and the addition of custom cations with variable stability. Cations of many types have been proposed for AEMs. Many include effective and stable, but rare, materials such as ruthenium, while others are difficult to synthesize or attached to polymers (e.g., sulfonium or phosphonium).
A number of random and diblock copolymer have been synthesized and converted into anion exchange membranes, and different cations and crosslinking methods have been used on anion exchange membranes. Some problems with these have included the shortcomings of solvent casting, such as limited solubility for copolymers—usually organic and sometimes hazardous—and a limited understanding of the solution properties (e.g., viscosity-concentration relationship to cast film thickness). For example, xylene may be used as a solvent to produce thin and mechanically robust films, but produces films having only modest conductivity.
There is a need for new anion exchange membranes.

Crosslinked membrane for anion exchange applications


According to one embodiment, in a semiconductor device, a semiconductor substrate has a first surface and a second surface which is opposed to the first surface. An insulating layer is provided on the first surface of the semiconductor substrate. A metal wiring is provided within the insulating layer. A support substrate is bonded to the insulating layer. A poly silicon electrode is connected to the metal wiring through a contact. A pad is provided on the second surface of the semiconductor substrate and is connected to the poly silicon electrode through a metal film deposited in a via-hole to penetrate the semiconductor substrate and extend to the poly silicon electrode.

As a semiconductor device containing a solid-state image sensing device, there is a back illumination complementary metal oxide semiconductor (CMOS) image sensor. In the back illumination CMOS image sensor, light enters from a back side of a substrate on which an electrode layer, a wiring layer, etc. are not disposed, the light is converted into an electric signal by a photo-diode, the electric signal is outputted to the outside of the substrate.
In the case of outputting the electric signal to the back side of the substrate, an electrode is provided on the back side of the substrate and is connected to a metal wiring layer through a via which penetrates the substrate.
Therefore, after the support substrate is bonded to the front side of the substrate on which the metal wiring layer is formed so that the substrate is reinforced, the substrate is ground from the back side so as to thin the substrate, and a via-hole is made by dry etching from the back side of the substrate. The dry etching is generally performed using a gas of fluorine system.
Accordingly, when the via-hole extends to the metal wiring layer during the dry etching, it is a problem that the metal wiring layer to which the via-hole extends is corroded by the gas of fluorine system.

Semiconductor device and method of manufacturing the same


The suspendable locker has a plurality of side walls and a top wall interconnected to define an interior space. The suspendable locker has an open bottom leaving the interior space exposed from below. A door is hingedly connected to a side wall to provide an access opening into the interior space along a side at the bottom so a cart can be rolled into and from the interior space. An attachment structure for suspending the locker from a storage cabinet is connected to a side wall. The attachment structure includes a pair of L-shaped flanges connected to an exterior surface of a side wall. The L-shaped flanges engage a lip on a tool storage cabinet, enabling the suspendable locker to be cantilevered from the storage cabinet.

The subject matter of this application relates to storage devices. More particularly, this application relates to a suspendable locker adapted to be coupled to a wall of a storage cabinet.
Large rolling tool cabinets are often used to secure tools which are kept at a job site. These tool cabinets may be placed at a central location in order to be easily accessible to those who use the tools. These tool cabinets are often heavily laden with tools, or other work articles, so it is often impractical to roll them to a particular work site. Consequently, small rolling carts are often employed to transport articles to the work site and back. At the end of the workday, the articles are removed from the rolling cart and placed back into the tool cabinet and secured.
Often it is desirable for mechanics and workmen to leave work pieces, equipment, or tools on a rolling cart undisturbed at the end of a work period, so that they may more easily continue their work where they left off the next period. Also, loading and unloading tools and other articles onto and off of the rolling cart can be quite time consuming, and sometimes objects will not readily fit into a tool cabinet. As a result, equipment and tools are often left on rolling carts unsecured.
Tool cabinets also usually cannot adequately store and secure computers, and are often too dirty an environment to keep paperwork. It is sometimes beneficial to have a computer and paperwork near a tool cabinet. Workmen and mechanics sometimes utilize computers to assist them at their jobs, and they almost always have paperwork to fill out and store. Since tool cabinets are not particularly adapted to store them, computers and paperwork are commonly stored elsewhere, sometimes making them less accessible.


A plant and a process are disclosed for producing components made of an aluminum alloy for vehicles and white goods, through the steps of: providing thixotropic billets made of an aluminum alloy; sizing the billets depending on a ratio between weight and size of the component to be produced, thereby obtaining crop ends of material; heating the crop ends in a range of temperatures during which both a solid phase and a liquid phase coexist with a prevalence in the solid phase (more than 50%) in heating means (5); loading, through loading means (9), the crop ends in an injecting vessel made of non-magnetic steel for further workings; removing, through scalping devices, an external part of the crop ends that has become cooled when passing from the heating means (5) to the loading means (9); firstly injecting the crop ends through a press; secondly injecting the crop ends through the press in 18 milliseconds by using a closed-loop control system and increasing the injection unit power with respect to a closing unit of the press; thirdly injecting the crop ends by coining the finished part in order to remove all porosities; extracting the molding through extracting means (13); depositing the molding onto a conveyor belt (15); and controlling a quality of the obtained molding, the molding being then sent to downstream mechanical workings and/or an heat treatment.

1) Field of the Invention
The present invention refers to a process and a plant for producing components made of an aluminium alloy for vehicles and white goods, and to the components obtained through the above-stated process and plant.
2) Background Art
In the field of parts made of an aluminium alloy for vehicles, a process and a plant of this type have been disclosed in WO-A-02081125 and WO-A-2007004241, of which the present invention is an improvement. In fact, the process and plant disclosed in WO-A-02081125 and WO-A-2007004241 are useful only for preparing small-sized parts for vehicles and, using a cast of thixotropic aluminium, do not obtain completely satisfactory parts. Moreover, these processes use a liquid detaching agent, whose disposal has negative impacts at environmental level.

Process and plant for producing components made of an aluminium alloy for vehicles and white goods, and components obtained thereby


A cell bias control circuit maximizes the performance of devices in the read/write path of memory cells (magnetic tunnel junction device+transistor) without exceeding leakage current or reliability limits by automatically adjusting multiple control inputs of the read/write path at the memory array according to predefined profiles over supply voltage, temperature, and process corner variations by applying any specific reference parameter profiles to the memory array.

Magnetoelectronic devices, spin electronic devices, and spintronic devices are synonymous terms for devices that make use of effects predominantly caused by electron spin. Magnetoelectronics are used in numerous information devices to provide non-volatile, reliable, radiation resistant, and high-density data storage and retrieval. The numerous magnetoelectronics information devices include, but are not limited to, Magnetoresistive Random Access Memory (MRAM), magnetic sensors, and read/write heads for disk drives.
Typically an MRAM includes an array of magnetoresistive memory elements. Each magnetoresistive memory element typically has a structure that includes multiple magnetic layers separated by various non-magnetic layers, such as a magnetic tunnel junction (MTJ), and exhibits an electrical resistance that depends on the magnetic state of the device. Information is stored as directions of magnetization vectors in the magnetic layers. Magnetization vectors in one magnetic layer are magnetically fixed or pinned, while the magnetization direction of another magnetic layer may be free to switch between the same and opposite directions that are called "parallel" and "antiparallel" states, respectively. Corresponding to the parallel and antiparallel magnetic states, the magnetic memory element has low (logic "0" state) and high (logic "1" state) electrical resistance states, respectively. Accordingly, a detection of the resistance allows a magnetoresistive memory element, such as an MTJ device, to provide information stored in the magnetic memory element. A high magnetoresistance (MR) value, which is the ratio of the resistance difference of the two states to the low resistance state, is desirable for increasing sensing signal and fast read operation.
There are two completely different methods used to program the free layer: field switching and spin-torque switching. In field-switched MRAM, current carrying lines adjacent to the MTJ bit are used to generate magnetic fields that act on the free layer. In spin-torque MRAM, switching is accomplished with a current pulse through the MTJ itself. The angular momentum carried by the spin-polarized tunneling current causes reversal of the free layer, with the final state (parallel or antiparallel) determined by the polarity of the current pulse. A reset current pulse will cause the final state to be parallel or logic "0". A set current pulse, in the opposite polarity of the reset current pulse, will cause the final state to be antiparallel or logic "1". Spin-torque transfer is known to occur in MTJ devices and giant magnetoresistance devices that are patterned or otherwise arranged so that the current flows substantially perpendicular to the interfaces, and in simple wire-like structures when the current flows substantially perpendicular to a domain wall. Any such structure that exhibits magnetoresistance has the potential to be a spin-torque magnetoresistive memory element.
Spin-torque MRAM (ST-MRAM), also known as spin-transfer torque RAM (STT-RAM), is an emerging memory technology with the potential for non-volatility with unlimited endurance and fast write speeds at much higher density than field-switched MRAM. Since ST-MRAM switching current requirements reduce with decreasing MTJ dimensions, ST-MRAM has the potential to scale nicely at even the most advanced technology nodes. However, the resistance of the MTJ is a small fraction of the voltage divider (for example, a word line select transistor, two column multiplexer transistors, and the bit and source lines) of the read/write path. The read operation requires precise control of the MTJ voltage drop, and the write operation requires optimum control of transistor devices for maximum write voltage, over PVT (process, voltage, and temperature), all the while meeting device reliability and leakage currents requirements.
Accordingly, circuitry and a method are disclosed for controlling the voltages or currents biasing the ST-MRAM cell. Furthermore, other desirable features and characteristics of the exemplary embodiments will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

Circuit and method for controlling MRAM cell bias voltages


A method for providing energy-efficient temperature and humidity control with uniform ventilation air distribution in a constant-volume zoned heating and cooling systems. The method utilizes an air-to-air heat exchanger that regulates the temperature of the supply air to a space, using the temperature differential between supply air and return (room) air and regulating the flow of return air through the heat exchanger.

Heating, ventilating and air conditioning (HVAC) systems serving multiple zones are classified according to the methods used to control the temperature and humidity in each zone. An early HVAC system commonly known as terminal reheat zone control was known to have superior space temperature and humidity control capability, but it was also known for consuming large amounts of energy in the cooling mode caused by the reheating process.
Another development in zone control came in the form of variable air volume (VAV) systems that regulate the supply air volume to a space in response to temperature requirement. These VAV systems, although good at controlling temperature, cannot ensure that the proper mixture of ventilation air reaches a room or zone because the total air volume varies with temperature needs. It is therefore not uncommon for the supply air volume to be low at a time of high occupancy, when a greater need for ventilation exists.
FIG. 2 is a prior art airflow diagram of a system such as described generally, for example, in U.S. Pat. No. 6,789,618 B2 of Pearson with a face damper to regulate the volume of air passing through each heat exchanger in the system for maintaining zone temperature and a bypass damper to route excess return air to the return duct. Return air to heat exchanger is either free-flow or directly connected. Return air leaving heat exchanger and face damper is directly connected to return air duct.

Constant air volume / variable air temperature zone temperature and humidity control system


A multicast processing method, apparatus and system. A Virtual eXtensible Local Area Network (VXLAN) tunnel end point (VTEP) receives configuration information sent by a management layer; and receives a multicast packet sent by a VM managed by the VTEP; when performing VXLAN encapsulation on the multicast packet after determining that the virtual machine (VM) matches the VM tenant identifier, the VTEP encapsulates a destination address of the multicast packet into the multicast address on a layer 3 network according to a mapping relationship between a VM multicast address and a multicast address on the layer 3 network, and encapsulates a VXLAN source address of the multicast packet into a layer 3 network multicast source address according to a mapping relationship between a VM multicast source address and a layer 3 network multicast source address; and sends an encapsulated multicast packet to the layer 3 network.

A VXLAN is a hotspot in network virtualization research and can establish a logical network (or an extended Virtual Local Area Network (VLAN)) on a physical network, and support implementation of long-distance virtual machine (VM) migration between geographically dispersed data centers. The VXLAN can finally provide long-distance segmentation support required by a multi-tenant cloud network. The VXLAN mainly solves a problem of tenants isolation in the data centers. In an existing isolation method, VLANs are generally used for isolation, but there are only 4096 VLANs, which cannot satisfy a requirement of isolating multiple tenants in the data centers. A VXLAN standard uses a 24-bit identifier named VXLAN network identifier (VNI). A maximum of 16 million VNIs can be defined in each management domain, and it is ensured that client data is isolated, because only VMs running with a same VNI can perform communication.
FIG. 1 shows a schematic networking diagram of a VXLAN according to the prior art, where multiple virtual VMs are made on servers in FIG. 1. The servers support a VXLAN tunnel end point (VTEP) function, where VNI22 is a network identifier of the VXLAN and allocated to a tenant, VMs of the tenant are distributed on SERVER1, SERVER3, SERVER4, and SERVER5, and there is no VM of the tenant on SERVER2 and SERVER6. When VM1-1 needs to communicate with VM5-1, the VM1-1 sends an Address Resolution Protocol (ARP) request packet, where the ARP request packet is first sent to VTEP1. When the VTEP1 does not learn an address of the VM5-1, the VTEP1 encapsulates the ARP request packet into a VXLAN broadcast packet, and broadcasts the VXLAN broadcast packet on a layer 3 network, where a used broadcast address is a layer 3 multicast address corresponding to the VNI22. If a server on which a VTEP is located does not have the tenant with the VNI22, this VTEP does not receive this broadcast packet, while a VTEP on a server that has a tenant with the VNI22 receives this broadcast packet. For example, VTEP5 on the SERVER5 receives this broadcast packet, and then, the VTEP5 removes a VXLAN header from the broadcast packet to obtain the ARP packet, and broadcasts the ARP packet to all VMs on the SERVER5. Because a target of the ARP packet is the VM5-1, only the VM5-1 responds to the ARP request packet, and no VM on another VTEP responds to the ARP request packet. An ARP response packet sent by the VM5-1 is also encapsulated into a VXLAN packet on the VTEP5. The VTEP5 sends an encapsulated VXLAN packet to the VTEP1, the VTEP1 removes a VXLAN header to obtain the ARP response packet and sends the ARP response packet to the VM1-1. In addition, the VETP1 performs ARP learning, and generates a corresponding ARP entry, so as to ensure subsequent communication between the VM1-1 and the VM5-1.
A management layer of the VXLAN allocates a fixed IP address and a fixed layer 3 multicast address to each VTEP, and the fixed IP address or layer 3 multicast address is used when a VXLAN unicast packet or multicast packet is encapsulated. However, such allocation is inapplicable to some application scenarios of VM multicast, and has the following deficiency:
The existing VXLAN does not support a multicast source selection function of the Internet Group Management Protocol version 3 (IGMPv3). A significant feature of the IGMPv3 is the multicast source selection function, that is, a client can select a multicast source according to requirements of the client. However, in the existing VXLAN technology, only one IP address and one or more multicast addresses are allocated to a VTEP. When processing multicast packets, the VTEP encapsulates all the multicast packets into VXLAN packets using a same multicast address, and a unicast address of the VTEP is used as a source address of a VXLAN packet. When multiple multicast sources are on a same SERVER, and the multicast sources and a client that sends a multicast request are not on a same SERVER, a VTEP of the SERVER on which the multicast sources are located cannot differentiate, according to the received VXLAN packet, which multicast source on the SERVER is requested by the client. As a result, the multicast client cannot receive a multicast packet sent by a selected multicast source.

Multicast processing method, apparatus and system


A semiconductor device comprises a first insulating film formed over a semiconductor substrate, a second insulating film formed on the first insulating film, a contact plug made of a conductive material vertically penetrating the first and second insulating films and extending on the second insulating film, and a conductor film in contact with the upper surface of the contact plug and part of the second insulating film. This construction makes it possible to form minute via-holes in a mass-production line without increasing parasitic capacity, increasing the number of manufacturing steps, and generating defects.

1. Field of the Invention
The present invention relates to a semiconductor device and a manufacturing method thereof, in particular, characterized by a stack structure of insulating layers which permits formation of minute via-holes without defects through a low-temperature process in a semiconductor highly-integrated circuit device such as a hybrid system LSI including a DRAM (Dynamic Random Access Memory).
2. Description of the Related Art
In recent progress of integration of semiconductor integrated circuit devices, SAC (Self-Align Contact) method, MDC (Modified Contact) method, PSC (Poly Shrink Contact) method, etc., are known for forming a minute via-hole in the manner that an opening portion is formed in an insulating layer interposed between interconnection layers. These methods of forming via-holes will be described below with reference to FIGS. 1A through 1C to FIGS. 4A through 4C.
First, a conventional SAC process will be described with reference to FIGS. 1A through 1C.
Referring first to FIG. 1A, interconnection lines 52 for, e.g., bit lines, are formed on an insulating underlayer 51 made of, e.g., SiO2, according to a design rule of 0.16 μm/0.24 μm for line/space. A SiN film is then formed by deposition, and anisotropically etched to form spacers 54.
In this case, for surely forming a certain space between the interconnection lines 52, the thickness of the SiN film must be 0.12 μm or less.
Note that, on the upper surface of each interconnection line 52, another SiN film 53 has been formed prior to the formation of the above-described SiN film. Besides, an electrode plug (not shown) has been provided at the portion in the insulating underlayer 51 corresponding to the space between the interconnection lines 52.
A thick insulating interlayer 55 made of, e.g., BPSG, is then formed on the entire surface by deposition. The surface of the insulating interlayer 55 is flattened through a CMP (Chemical Mechanical Polishing) or etch-back process. A resist pattern (not shown) for 0.24 μm-wide via-holes is formed using a photolithographic technique. Anisotropic etching is carried out using the SiN films 53 and the spacers 54 as etching stoppers, to form a via-hole 56.
Referring next to FIG. 1B, a thick amorphous Si layer 57 doped with, e.g., P (phosphorus), is formed on the entire surface by deposition.
Referring next to FIG. 1C, polishing by CMP method is carried out until the surface of the insulating interlayer 55 is exposed. The part of the doped amorphous Si layer 57 formed on the insulating interlayer 55 is thereby removed to form a Si plug 58 filling in the via-hole 56.
Next, a conventional MDC process will be described with reference to FIGS. 2A through 2D.
Referring first to FIG. 2A, interconnection lines 52 for, e.g., bit lines, are formed on an insulating underlayer 51 made of, e.g., SiO2, according to a design rule of 0.16 μm/0.24 μm for line/space. A thick insulating interlayer 55 made of, e.g., BPSG, is then formed on the entire surface by deposition. The surface of the insulating interlayer 55 is flattened through a CMP or etch-back process. A resist pattern (not shown) for 0.24 μm-wide via-holes is formed using a photolithographic technique. Anisotropic etching is carried out using the interconnection lines 52 as etching stoppers, to form a via-hole 56.
An electrode plug (not shown) has been provided at the portion in the insulating underlayer 51 corresponding to the space between the interconnection lines 52.
Referring next to FIG. 2B, an insulating film 59 made of, e.g., SiN, having an etching selectivity to the BPSG film, is formed by deposition.
In this case, for surely forming a certain space between the interconnection lines 52 in the subsequent anisotropic etching process, the thickness of the insulating film 59 must be 0.12 μm or less, in particular, 0.1 μm or less.
Referring next to FIG. 2C, anisotropic etching is carried out to form spacers 60, which newly define a via-hole 61 between them.
Referring next to FIG. 2D, a thick amorphous Si layer doped with, e.g., P (phosphorus), is formed on the entire surface by deposition. Polishing by CMP method is then carried out until the surface of the insulating interlayer 55 is exposed. The part of the doped amorphous Si layer formed on the insulating interlayer 55 is thereby removed to form a Si plug 62 filling in the via-hole 61.
Next, a conventional PSC process will be described with reference to FIGS. 3A through 3C and 4A through 4C.
Referring first to FIG. 3A, interconnection lines 52 for, e.g., bit lines, are formed on an insulating underlayer 51 made of, e.g., SiO2, according to a design rule of 0.16 μm/0.24 μm for line/space. A thick insulating interlayer 55 made of, e.g., BPSG, is then formed on the entire surface by deposition. The surface of the insulating interlayer 55 is flattened through a CMP or etch-back process. An amorphous Si layer 63 having an etching selectivity to the insulating interlayer 55 is then formed on the entire surface by deposition, into a thickness of, e.g., 0.3 μm.
An electrode plug (not shown) has been provided at the portion in the insulating underlayer 51 corresponding to the space between the interconnection lines 52.
Referring next to FIG. 3B, a resist pattern (not shown) for 0.24 μm-wide via-holes is formed using a photolithographic technique. Anisotropic etching is then carried out using the insulating interlayer 55 as an etching stopper, to form an opening portion 64 in the amorphous Si layer 63.
Referring next to FIG. 3C, another amorphous Si layer is formed on the entire surface by deposition, into a thickness of, e.g., 0.12 μm or less. Anisotropic etching is then carried out to form Si spacers 65, which newly define an opening portion 66 between them.
Referring next to FIG. 4A, anisotropic etching is carried out using the amorphous Si layer 63 and the Si spacers 65 as etching masks, to form a via-hole 67.
Referring next to FIG. 4B, a thick amorphous Si layer 68 doped with, e.g., P (phosphorus), is formed on the entire surface by deposition.
Referring next to FIG. 4C, polishing by CMP method is carried out until the surface of the insulating interlayer 55 is exposed. The part of the doped amorphous Si layer 68 formed on the insulating interlayer 55 is thereby removed to form a Si plug 69 filling in the via-hole 67.
Next, a manufacturing method of a conventional hybrid system LSI including a DRAM will be described with reference to FIGS. 5A and 5B to FIGS. 14A and 14B, in which a via-hole for a storage node is formed through a PSC process among techniques for forming such a via-hole in a self aligning manner.
FIGS. 5A, 7A, 9A, 11A and 13A are sectional views of a memory cell portion. FIGS. 5B, 7B, 9B, 11B and 13B are sectional views of an alignment mark portion at the same stages as those of FIGS. 5A, 7A, 9A, 11A and 13A, respectively. FIGS. 6A, 8A, 10A, 12A and 14A are sectional views perpendicular to those of FIGS. 5A, 7A, 9A, 11A and 13A, respectively. FIGS. 6B, 8B, 10B, 12B and 14B are sectional views of a logic transistor portion.
Referring first to FIGS. 5A to 6B, electrically insulating regions 72 for element isolation are formed in a p-type silicon substrate 71 through an STI (Shallow Trench Isolation) process.
The p-type silicon substrate 71 may be substituted by a p-type well formed in an n- or p-type silicon substrate. Besides, channel stop regions or doped channel regions may be formed therein through an ion implantation process, at need.
Next, a gate oxide film 73 is formed by thermal oxidation using wet O2 gas. An amorphous Si film is then formed by deposition into a thickness of, e.g., 100 nm. The amorphous Si film is doped with As or P by ion implantation. A conductive Si gate electrode layer 74 is obtained thereby.
Next, a 100 nm-thick WSi2 film 75 is formed by deposition, for example. Subsequently, a 100 nm-thick P—SiN film 76 is formed through a plasma CVD process, for example. After this, in the DRAM portion, patterning by etching are carried out using a photolithographic technique, according to a design rule of, e.g., 0.20 μm/0.20 μm for line/space, to form gate electrodes and word lines successive from the gate electrodes.
The length of the gate electrode in the logic transistor portion of FIG. 6B is, e.g., 0.18 μm.
Next, for n-channel FET portions, ion implantation with P is carried out. In the DRAM portion, n-type drain and source regions 77 and 78 are formed thereby. At the same time, in the logic transistor portion, n-type LDD (Lightly Doped Drain) regions 79 are formed.
Next, a SiN film 80 of a thickness of, e.g., 60 nm, is formed on the entire surface through a CVD process. After this, while masking the DRAM portion with a resist, anisotropic etching is carried out to form a spacer 81 on either side wall of the gate electrode in the logic transistor portion. Ion implantation with As is then carried out using the spacers 81 as masks, to form n+-type drain and source regions 82 and 83. After this, defects attendant upon ion implantation are repaired through an RTA (Rapid Thermal Anneal) process, e.g., heat treatment at 1000° C. for 10 seconds.
Next, a Co film is formed on the entire surface by deposition, into a thickness of, e.g., 50 nm. Heat treatment at 500° C. for 30 seconds is then carried out to form silicide electrodes 84 of CoSi2 only on the surfaces of the n+-type drain and source regions 82 and 83. Subsequently, etching is carried out with a mixture solution of hydrogen peroxide and ammonia or a mixture solution of sulfuric acid and hydrogen peroxide to remove unreacted Co.
Next, a SiN film 85 of a thickness of, e.g., 20 nm, is formed on the entire surface through a CVD process.
In this case, by forming the SiN film 85 in a growth device with a load lock system, oxidation of the silicide electrodes 84 by oxygen engulfed during the growth of the SiN film 85 can be successfully prevented.
Next, a BPSG film 86 is formed on the entire surface by deposition. In the DRAM portion, bit and storage contacts are then formed through an SAC process.
In this case, after a resist pattern (not shown) for 0.24 μm-wide via-holes is formed using a photolithographic technique, the BPSG film 86 is etched by double-channel RIE (Reactive Ion Etching) using C4F8+CO+Ar+O2 gas. Subsequently, the SiN film 85 is etched to expose the n-type drain and source regions 77 and 78.
In this etching process, sidewalls 87 are formed on the opposed side surfaces of the gate electrodes. These sidewalls 87 prevent short circuits between the gate electrodes and Si plugs 88 and 89 which will be described later.
As the capacitance on each gate electrode, i.e., word line, the capacitance between it and the p-type silicon substrate 71 across the gate oxide film 73 is dominant. Therefore, an increase in capacitance due to use of SAC method matters little.
Next, a thick amorphous Si layer doped with, e.g., P, is formed by deposition. Polishing is then carried out until the surface of the BPSG film 86 is exposed. The part of the doped amorphous Si layer formed on the BPSG film 86 is thereby removed to form Si plugs 88 and 89 filling in via-holes.
Next, a P—SiO2 film 90 of a thickness of, e.g., 100 nm, is formed on the entire surface through a plasma CVD process. A via-hole is then formed for the Si plug 88 which is to serve as a bit contact. After this, a Ti film of a thickness of, e.g., 20 nm, a TiN film of a thickness of, e.g., 50 nm, and a W film of a thickness of, e.g., 100 nm, are formed in order on the entire surface by deposition. These films are then patterned into a predetermined shape to form bit lines 91 of the Ti/TiN/W structure.
In this case, the bit lines 91 are formed according to a design rule of 0.16 μm/0.24 μm for line/space, for example.
At this time, in the alignment mark portion, alignment marks 92 of the Ti/TiN/W structure are formed, as shown in FIG. 5B.
Next, a SiO2 film 93 of a thickness of, e.g., 700 nm, is formed through an HDP (High Density Plasma)-CVD process. Subsequently, the SiO2 film 93 is polished by about 200 nm through a CMP process to flatten the surface of the SiO2 film 93.
Referring next to FIGS. 7A to 8B, an amorphous Si layer 94 of a thickness of, e.g., 300 nm, is formed on the entire surface by deposition. The part of the amorphous Si layer 94 above the alignment marks 92 is then removed by rough patterning to form a window portion 95.
This is because the amorphous Si layer 94 is opaque in relation to visible light. That is, when such a thick amorphous Si layer 94 having its thickness of 300 nm is present above the alignment marks 92, detection of the alignment marks 92 may become impossible.
Referring next to FIGS. 9A to 10B, a resist pattern (not shown) for via-holes of a width of 0.24 μm(=240 nm) is formed using a photolithographic technique. Subsequently, anisotropic etching is carried out to form an opening portion at the position in the amorphous Si layer 94 corresponding to the Si plug 89 which is to serve as a storage contact. After this, another amorphous silicon layer of a thickness of, e.g., 95 nm, is formed on the entire surface by deposition. Subsequently, anisotropic etching is carried out to form Si spacers 95 whose maximum width is 95 nm. After this, anisotropic etching is carried out using the Si spacers 95 and the amorphous Si layer 94 as masks, to form a via-hole 98 whose minimum width is 0.05 μm(=50 nm=240 nm−2×95 nm).
At this time, the alignment mark portion is covered with a resist 97, thereby preventing the SiO2 film 93 at that portion from being etched off to expose the alignment marks 92.
Referring next to FIGS. 11A to 12B, an amorphous Si layer of a thickness of, e.g., 200 nm, doped with, e.g., P, is formed on the entire surface by deposition. Subsequently, polishing is carried out until the surface of the SiO2 film 93 is exposed through a CMP process. The part of the doped amorphous Si layer formed on the amorphous Si layer 94, the amorphous Si layer 94, and the Si spacers 95 are thereby removed to form a Si plug 99 filling in the via-hole 98.
At this time, a lower part of each Si spacer 95 may remain as a residual Si spacer portion 100.
Referring next to FIGS. 13A to 14B, an LP—SiN film 101 which is to serve as etching stoppers in the subsequent stages, is formed into a thickness of, e.g., 10 nm, through a low-pressure chemical vapor deposition (LPCVD) process. A BPSG film (not shown) of a thickness of, e.g., 1 μm, is then formed on the entire surface by deposition.
Next, the BPSG film and the LP—SiN film 101 are etched in order, to form a wide opening portion which reaches the Si plug 99 formed by PSC method. After this, an amorphous Si layer of a thickness of, e.g., 50 nm, doped with P, is formed on the entire surface by deposition. Subsequently, the part of the doped amorphous Si layer formed on the BPSG film is removed through a CMP process to form a storage node 102 having cylindrical outer and inner surfaces.
Next, the BPSG film is selectively removed with an HF aqueous solution using the LP—SiN film 101 as an etching stopper. Subsequently, a SiN film of a thickness of, e.g., 5 nm, is formed on the surface of the storage node 102 through an LPCVD process at, e.g., 700° C. The SiN film is to serve as a dielectric layer of a capacitor. After this, an amorphous Si film of a thickness of, e.g., 100 nm, doped with P, is formed on the entire surface by deposition to form a cell plate 103 common for storage nodes 102.
In the subsequent process not illustrated, an insulating interlayer is formed on the entire surface. Heat treatment by RTA method at 900° C. for 10 seconds is carried out for re-activation to ensure a certain current of each MOSFET. After this, wiring process and so on are performed. A system LSI in which a DRAM is incorporated is obtained thereby.
In the above RTA process for re-activation, since no thick plasma SiN film exists, peeling or cracking thereof never occurs.
The above-described conventional formation methods of via-holes, however, include various problems. This will be discussed below.
For example, in case of the SAC method as shown in FIGS. 1A to 1C, the device has a COB (Capacitor Over Bit-line) structure in which interconnection lines 52, i.e., bit lines, are under the capacitor. When the via-hole 56 is for a storage node contact, if the via-hole 56 is formed through a usual selective etching process with double-channel RIE using C4F8+CO+Ar+O2 gas, the side surface of each interconnection line 52 must be covered with a SiN film having an etching selectivity in relation to the insulating interlayer 55 made of, e.g., BPSG.
However, such a SiN film has a high relative dielectric constant. Besides, in case of SAC method, the area of the opening of the via-hole 56 over the interconnection lines 52 cannot but be large in comparison with that of MDC or PSC method. This causes the problem that the capacitance between each bit line and the storage node increases.
For example, when the relative dielectric constant of SiN is represented by ε, the dielectric constant of vacuum is represented by ε0, the surface area is represented by S, and the distance between the electrodes is represented by d, the capacity C of the capacitor is expressed by:C=(ε×ε0×S/d)
The relative dielectric constant of SiN is 7.4, which is approximately double that of SiO2.
Such an increase in capacity makes it hard to reduce the number of sense amplifier divisions. This causes an increase in chip area.
Next, problems in use of the MDC method as shown in FIGS. 2A to 2D will be discussed. When each spacer 60 in the via-hole 56 is made of SiN, there arises the problem of increasing the capacity between each bit line and the storage node, like the case of the above-discussed SAC method.
Otherwise, it is thinkable that each spacer 60 in the via-hole 56 is made of SiO2 whose relative dielectric constant is low. In this case, however, the following problems arise. The film for forming such a spacer is required to have a good step coverage ability. On the other hand, as a demand of such a hybrid system LSI including a DRAM, in order to prevent deterioration of performance of a logic circuit because of, e.g., occurrence of short-channel effect due to change in impurity profile of source/drain regions, a low-temperature process is required for the DRAM having a COB structure. For example, a furnace annealing process at 700° C. or less is required.
As a method for forming a SiO2 film with good step coverage ability through such a low-temperature process, known is LP-TEOS method capable of forming a film at 650° C. However, the LP-TEOS film formed by this method can not be densified and reduces in its anti-breakdown property unless it is subjected to a heat treatment at about 800° C. in the atmosphere of N2. Therefore, this method can not be used for such a hybrid system LSI including a DRAM.
No other formation method of a SiO2 film with good step coverage ability through a low-temperature process is present if mass-productivity in a factory is taken into consideration.
Next, problems in use of the PSC method as shown in FIGS. 3A to 3C and FIGS. 4A to 4C will be discussed. If a hard mask and spacers formed on the side surfaces thereof, which are to serve as etching masks, are made of polycrystalline Si, since polycrystalline Si is opaque in relation to visible light, alignment marks cannot be detected upon formation of via-holes, as described in connection with FIG. 7B.
With recent progress of minuteness in semiconductor device, resolution in photolithographic process has also been improved. Since the higher resolution requires the shallower focal depth, the surface of the insulating interlayer 55 must be flattened. If the surface has been flattened, however, unevenness in height caused by the alignment marks for photolithography may disappear, and detection of the alignment marks may become impossible through the opaque film.
For this reason, as described in connection with FIG. 7B, for removing the amorphous Si layer 93 over the alignment marks 92, two steps of resist pattern formation and etching are necessary as extra steps. Furthermore, in order to prevent the alignment marks 92 from being exposed during the formation process of the via-hole 98, a formation process of the resist 97 is necessary. These hinder a reduction of cost and a higher throughput.
Besides, in case of bit lines 91 made of a metal, if the alignment marks 92 are formed at a level of an interconnection layer lower than the bit lines 91, the alignment must be done indirectly and so the positional deviation may become large. For this reason, the alignment marks are usually formed using the bit lines 91. In this case, however, if the formation process of the resist 97 is omitted, the metal alignment marks 92 may be exposed during the formation process of the via-hole 98. This may cause a metallic contamination of the depositing device for the doped amorphous Si layer for forming the Si plug in the subsequent stage. Therefore, the device only for that process must be used. In a usual factory, however, such a limited use of the device is hard.
Consequently, when the bit lines are made of a metal, the three extra steps in total become necessary.
Further, problems in a minute via-hole formation process by the PSC method in which furnace annealing only at 700° C. or less can be carried out because metal interconnection lines exist in a lower layer as represented by a hybrid system LSI including a DRAM, will be discussed with reference to FIG. 15.
Referring to FIG. 15, when a via-hole 67 is formed in a 500 nm-thick insulating interlayer 55, an amorphous Si layer 63 as a hard mask requires its thickness of 300 nm.
This is because the plasma in the etching process for forming the via-hole 67 is apt to concentrate at corner portions, and so etching rapidly progresses in the interface between the amorphous Si layer 63 and each Si spacer 65. This may result in generation of abnormal etching portions 70.
Alternatively, when an LP—SiN film formed through an LPCVD process is used as the hard mask, 270 minutes(=4.5 hours) is required for the LP—SiN film having grown to a thickness of 300 nm at 700° C. or less. This causes a problem on throughput.
Besides, when a plasma CVD process is used for the hard mask and a BPSG film exists in the lower layer, the P—SiN film formed through the process may crack if its thickness is 100 nm or more.
More specifically, When the P—SiN film is put in a formation process of a capacitor dielectric film or a RTA process for re-activation of source/drain regions after formation of the via-hole 67, the stress exerted on the P—SiN film changes from compression to tensile due to heat of 650° C. or more. This may cause peeling off or cracking.

Semiconductor device and manufacturing method thereof