An apparatus and method are present which use X-ray fluorescence techniques to determine the roughness of a target surface. The apparatus includes an X-ray source and an X-ray detector. The X-ray source produces primary X-ray photons formed into a primary X-ray beam, and the primary X-ray beam is directed to and incident upon the target surface. The X-ray detector is positioned to receive primary X-ray photons scattered by the target surface. A fraction of the primary X-ray photons scattered by the target surface is directly proportional to the roughness of the target surface. The roughness of the target surface is determined from the number of primary X-ray photons scattered by the target surface and received by the X-ray detector within a predetermined exposure time. The X-ray detector produces an output signal proportional to the energy levels of received X-ray photons. An energy range of interest is divided into segments. A computer system receives the X-ray detector output signals and increments corresponding counts associated with segments of the energy range of interest. Following exposure, the computer system produces a graph of the counts associated with each segment. The computer system also reviews the counts associated with a peak in the graph corresponding to the energy levels of the scattered primary X-ray photons, determines selected characteristics of the peak (e.g., a maximum count associated with the peak, the area under the peak, etc.), and uses calibration data to compute a surface roughness value.

1. Field of the Invention
This invention relates to integrated circuit manufacturing and more particularly to determining the roughness of a surface of a target material.
2. Description of the Relevant Art
High quality gate oxides are essential to the manufacture of MOS transistors with stable and reliable operating characteristics. A layer of an electrical insulating material separates a gate electrode of a metal oxide semiconductor (MOS) transistor from an underlying substrate channel region between a source region and a drain region. This insulating layer is commonly made of silicon dioxide (oxide), and the oxide insulating layer is called a gate oxide. A voltage applied to the gate electrode in excess of a minimum "threshold" level attracts enough electrical charges into the channel region to form a conducting path between the source and drain regions.
In order to increase the current sourcing and sinking abilities (i.e., current drives) of MOS transistors, gate oxides are typically made as thin as possible. As the strength of the electric field developed between the gate electrode and the underlying substrate channel region and within the gate oxide is inversely proportional to the thickness of the gate oxide, thinner gate oxides must withstand higher electric field strengths. The maximum electric field strength a gate oxide can withstand before destructively breaking down depends upon the thickness of the gate oxide and the quality of the gate oxide. Thus thinner gate oxides must be of higher quality.
Electrical "oxide rupture" or "rupture voltage" measurements are often performed upon test structures (i.e., MOS capacitor structures) fabricated upon wafers in order to determine gate oxide quality. An oxide layer to be analyzed is formed on an upper surface of a semiconductor substrate, and an electrode is formed on an upper surface of the oxide layer. During rupture voltage testing, a voltage applied to the electrode is continually increased until the oxide is physically destroyed (i.e., "ruptures") and current flows freely from the electrode to the underlying substrate. The maximum applied voltage (i.e., electric field strength) that the oxide can withstand before breakdown is a function of the oxide thickness and quality.
"Pinhole" defects in oxides can cause unacceptably low oxide breakdown voltage levels (i.e., electric field strengths). FIG. 1 is a partial cross-sectional view of an MOS capacitor structure 10. MOS capacitor structure 10 includes an oxide layer 12 formed upon an upper surface of a semiconductor substrate 14, and an electrode 16 formed upon an upper surface of oxide layer 12. Oxide layer 12 is shown to include a pinhole defect 18 in the upper surface of oxide layer 12. Pinhole defect 18 is filled with the conductive material of electrode 16 when electrode 16 is formed. The thickness of oxide layer 12 is reduced in region 20 surrounding pinhole defect 18. During rupture voltage testing, the strength of the electric field between electrode 16 and substrate 14 within oxide layer 12 is greatest in region 20, and oxide layer 12 is more likely to fail first in region 20. The presence of pinhole defect 18 is thus likely to result in a measured breakdown voltage that is lower than expected.
Pinhole defects may be identified in very small "sample" regions of an upper surface of an oxide layer using microscopy. One such method is atomic force microscopy (AFM). AFM allows an area about 10 microns square to be viewed for the presence of pinhole defects. The equipment needed to perform AFM is, however, large and expensive, and studying a sufficient portion of an upper surface of an oxide layer in order to determine the number of pinhole defects present per unit of surface area would be time consuming. Thus AFM cannot be used efficiently in a manufacturing environment subject to volume production.
Oxide surfaces having few pinhole defects tend to be smooth, and oxide surfaces having a large number of pinhole defects per unit of surface area tend to be rough. Thus a measurement of the roughness of the upper surface of an oxide layer reflects the number of pinhole defects per unit of surface area (i.e., the quality of the oxide layer). It would thus be desirable to have a surface roughness measurement technique which is relatively fast and inexpensive, does not involve physical contact with structures on wafers (i.e., non-contact), and also does not result in the destruction of a specimen (i.e., non-destructive). Such a technique could be used to determine the qualities of oxides formed upon product wafers (i.e., wafers expected to yield operational integrated circuits), and would be well suited for use in a high-volume manufacturing environment.
X-ray fluorescence (XRF) spectroscopy techniques are commonly used to determine the elemental compositions of materials. In semiconductor manufacturing applications, a beam of primary X-ray photons is directed at the surface of a semiconductor wafer, and the energy levels (or corresponding wavelengths) of resultant secondary X-ray photons emitted by atoms of elements on and just under the surface of the wafer are measured. Atoms of elements in target materials emit secondary X-ray photons with uniquely characteristic energy levels (or corresponding wavelengths). Thus the elemental compositions of materials on and just under the surface of the wafer may be determined from the measured energy levels (or wavelengths) of emitted secondary X-ray photons. XRF spectroscopy techniques offer rapid, non-contact, non-destructive determination of elemental composition down to trace quantities over a wide range of elements with no sample preparation, and is thus a highly desirable tool for in-line product wafer examination.
FIG. 2 is a side elevation view of a typical XRF spectroscopy apparatus 22. Apparatus 22 includes a high-power X-ray source 24, a sample stage 26, an X-ray detector 28, and a computer system 30. A planar backside surface of a semiconductor wafer 32 is placed on a flat upper surface of a sample stage 26, allowing a planar frontside surface of semiconductor wafer 32 to be subjected to primary X-ray photons during analysis. X-ray source 24 must be a high-power X-ray source in order to produce a relatively large number of X-ray photons per unit time. X-ray source 24 produces a beam of primary X-ray photons 34. The X-ray photons making up primary X-ray beam 34 strike the frontside surface of semiconductor wafer 32 within an exposed region, and have sufficient energy (i.e., sufficiently short wavelengths) to cause atoms of elements of interest located on and just under the surface of semiconductor wafer 32 to emit secondary X-ray photons. A portion of the X-ray photons making up primary X-ray beam 34 and striking the frontside surface of semiconductor wafer 32 are reflected away from the surface, forming a reflected primary X-ray beam 36.
Atoms of elements on and just under the exposed region of the frontside surface of semiconductor wafer 32 absorb a fraction of the incident primary X-ray photons and emit characteristic secondary X-ray photons. FIGS. 3, 4a, and 4b will be used to describe this phenomenon. FIG. 3 is a side elevation view of a primary X-ray photon 40 incident upon a target material 42, resulting in the emission of a secondary X-ray photon 44 by target material 42. X-ray photon absorption and emission occur at the atomic level. XRF spectrometry permits examination of target material 42 from the surface of the target material down to a maximum escape depth 46 of secondary X-ray photons.
FIG. 4a is a representation of an atom 48 of target material 42. In the simple atomic model shown, atom 48 has a nucleus 50 surrounded by electrons 52 at different discrete distances from nucleus 50 called electron shells. A given electron shell has a binding energy level equal to the amount of energy required to remove an electron from the electron shell. The binding energy level of an electron shell is inversely proportional to the distance of the electron shell from the nucleus. The innermost electron shell of an atom is called the K shell, and has the highest binding energy level associated with it. In FIG. 4a, K-shell electron 54 is located in K shell 56.
FIG. 4a also shows primary X-ray photon 40 impacting atom 48 within target material 42. If the energy level of primary X-ray photon 40 (E) is greater than the binding energy level of a K shell 56 (.phi..sub.K), the entire energy of primary X-ray photon 40 is absorbed by atom 48, and one of the electrons in K shell 56 is ejected from atom 48. As depicted in FIG. 4a, K-shell electron 54 is ejected from atom 48 after primary X-ray photon 40 is absorbed by atom 48. K-shell electron 54 is ejected with a kinetic energy of (E-.phi..sub.K).
With a vacancy in K shell 56, atom 48 is energetic and unstable. The most probable stabilization mechanism is the filling of the vacancy in K shell 56 by an electron located in an electron shell with a lower binding energy level. As shown in FIG. 4b, an L-shell electron 58 in L shell 60, farther from nucleus 50 than K shell 56, may fill the vacancy in K shell 56. As L-shell electron 58 fills the vacancy in K shell 56, atom 48 simultaneously emits secondary X-ray photon 44 with energy (.phi..sub.K -.phi..sub.L). where .phi..sub.l is the binding energy level of L shell 60. With a vacancy now in L shell 60, ionized atom 48 is more stable and less energetic. The energy levels (or corresponding wavelengths) of secondary X-ray photons emitted by atoms of elements in substances on and just under the surface of a target material are uniquely characteristic, allowing the elemental compositions of the substances to be determined.
Referring back to FIG. 2, X-ray detector 28 is positioned directly above the exposed region of the frontside surface of semiconductor wafer 30. X-ray detector 28 receives characteristic secondary X-ray photons and scattered primary X-ray photons, and produces an output signal which represents the energy levels of detected X-ray photons. Computer system 30 is coupled to receive and process the output signals produced by X-ray detector 28. An energy range of interest, which includes the energy levels of primary X-ray photons and secondary X-ray photons emitted by expected elements, is divided into several energy subranges. Computer 30 maintains counts of the number of X-ray photons detected within each subrange. After a predetermined exposure time, computer system 30 stops receiving and processing output signals and produces a graph of the counts associated with each subrange.
FIG. 5 is a representative graph of the counts associated with each subrange. Such a graph is basically a histogram representing the frequency distribution of the energy levels of detected X-ray photons, and is called a spectral pattern. Peaks in the frequency distribution (i.e., relatively high numbers of counts) occur at energy levels of scattered primary X-ray photons (E3) and at predominant characteristic emission energy levels (E1 and E2) of atoms of elements located on and just under the frontside surface of semiconductor wafer 32 within the exposed region. The peak in the frequency distribution occurring at energy levels of scattered primary X-ray photons (E3) is basically ignored. Energy levels E1 and E2 associated with the other two peaks in the frequency distribution are used to identify the one or more elements present on and just under the exposed region of the frontside surface of semiconductor wafer 32 according to well-known XRF methods.
A primary X-ray photon incident upon a target material may be absorbed or scattered. Characteristic secondary X-ray photons are emitted only when primary X-ray photons are absorbed. Primary X-ray photons may loose energy when scattered by atoms of the target material. Such scattered primary X-ray photons which reach the X-ray detector of an XRF instrument create an unwanted background intensity level which secondary X-ray photons must exceed in order to be discerned. Thus the smallest amount of an element which may be detected in a sample using an XRF instrument is largely determined by the background intensity level at the energy level (or corresponding wavelength) associated with characteristic secondary X-ray photons emitted by that element. The sensitivity of an XRF instrument is thus largely dependent upon the background intensity level, and the sensitivity of an XRF instrument may be improved by reducing the amount of scattered primary X-ray photons reaching the detector.
Total reflection X-ray fluorescence (TXRF) is an XRF technique ideally suited for the examination of semiconductor wafers and other materials with substantially planar surfaces. In TXRF, an angle of incidence formed between an incident primary X-ray beam and a substantially planar sample surface is very small, typically less than 0.2 degree. At such small angles of incidence, almost all of the primary X-ray photons striking the sample surface are reflected away from the surface. Primary X-ray photons are also reflected away from an X-ray detector positioned over the region of the wafer surface where the primary X-ray beam impacts the wafer surface. The number of scattered primary X-ray photons reaching the detector is thus significantly reduced. As a result, surface analysis instruments employing TXRF techniques have reduced background intensity levels over other types of XRF analysis instruments. Smaller quantities of elements may be detected with TXRF instruments due to their greater sensitivities.
It would thus be desirable to have a surface roughness measurement technique based upon the scattering of X-ray photons from the surface of a target material. Such a surface roughness measurement technique would be relatively fast and inexpensive, would be non-contact, and would also be non-destructive. Such a surface roughness measurement technique could be used to determine the qualities of oxides formed upon product wafers, and would be well suited for use in high-volume manufacturing environments.

Apparatus and method for measuring the roughness of a target material surface based upon the scattering of incident X-ray photons


Image data including depth data on a pixel basis representing a sphere or column are previously generated and stored in a mapping memory. When the sphere or column is to be displayed on a display screen, the image data are read out from the mapping memory. The image data thus read out are mapped to a predetermined region of a memory for display and are processed for hidden surface removal simultaneously.

1. Field of the Invention
This invention relates to a method and apparatus for displaying a three dimensional object, and more particularly, to a method and apparatus suitable for displaying a sphere, a column and the like on a display screen.
2. Description of Related Arts
In conventional graphics system for displaying images of objects in three dimensions, filling and displaying of the various three dimensional objects are performed by dividing a surface of each three dimensional object to be displayed into a plurality of triangles or quadrilaterals, obtaining color data for every pixel through applying luminance calculation for each divided figure, then filling and displaying each divided figure based on the obtained color data. Display with reality can be accordingly performed by taking each light source vector (a vector starting from a reflecting point and directed to a light source) and each view point vector (a vector starting from a reflecting point and directed to a view point) into consideration, regardless of the species of the three dimensional object. However, a disadvantage of a remarkable increase in the necessary time period between starting operations and visually displaying a three dimensional object, has arisen. This is caused by the fact that a three dimensional object should be divided into a great many triangles or quadrilaterals when the quality of the displayed three dimensional object is to be improved, thereby resulting in greatly increasing the amount of operations and processings.
When the three dimensional object to be displayed is a sphere, the display is scarcely changed even when each light source vector and view point vector are greatly varied. But the same operations and processings as the above-mentioned operations and processings, are needed for every sphere to be displayed, thereby resulting in lengthening the time period for display beyond that which is necessary. Also, when a three dimensional object to be displayed is a column, the display is changed little even when each light source vector and view point vector are greatly varied. But the same operations and processings as the above-mentioned operations and processings, are needed for every column to be displayed, thereby resulting in lengthening the time period for display beyond that which is necessary. The similar disadvantage has arisen when a three dimensional object to be displayed is not a sphere or a column and is not greatly changed even when a light source vectors and a view point vectors vary.
To be more specific, when a three dimensional object is a free shape, the repeated display of the three dimensional object in a graphics system for displaying images of objects in three dimensions, in general is not of great concern. As a result, the above-mentioned disadvantage is not widely recognized. However, in certain situations a sphere, a column and the like are necessary, for example, in displaying of chemical molecular structure used in molecular design. Where a great many spheres and columns are frequently and repetitively displayed on the same screen is one of those situations. As a result, the above-mentioned disadvantage is recognized as a problem.

Apparatus for displaying a three dimensional object which appears substantially the same in different display directions by modifying stored image data by a scale factor


A method for manufacturing a semiconductor device is disclosed suitable for a substrate having a first conducting structure and a first dielectric layer, wherein the dielectric layer covers the first conductive structure. The method includes the steps of forming a second conductive structure over the substrate adjacent to the first conductive structure. Then, the size of the second conductive structure is reduced so that a top surface of the second conductive structure is relatively lower than that of the first conductive structure. Thereafter, a second dielectric layer is formed over the substrate to cover the first and the second conductive structure. A via is formed in the second dielectric layer to expose the top surface of the first conductive structure. Finally, a via plug is formed in the via.

1. Field of the Invention
The present invention generally relates to a fabrication method of a semiconductor device. More particularly, the present invention relates to a fabrication method of a metal interconnect for a semiconductor device.
2. Description of Related Art
The higher the level of integration for integrated circuits, the smaller the semiconductor devices are being developed. Therefore, the size of the devices, for example, the width of the conducting line, the size of the gate, and the dimension of the plug shrinks to increase the level of integration. However, due to the miniaturizing of component devices, the difficulties in the manufacturing process greatly increase, and the demand for size precision also increases.
According to the conventional photolithography and etching processes, a misalignment often occurs during photolithography process in forming a contact window opening that exposes the source/drain region or a gate or a via that exposes the surface of an interconnect in the dielectric layer of a memory device (ex: a flash memory) or an interconnect (ex: a conducting line), due to the increase of the level of integration and the miniaturization of the device dimension. Furthermore, the misalignment during the photolithography process often leads to an exposure of other component devices neighbouring to the source/drain region, the gate or the interconnect, designated to be exposed.
Turning to FIG. 1, FIG. 1 illustrates the cross sectional views of the contact window openings for exposing a gate and a source region of the conventional trench flash memory. The conventional fabrication method for forming the contact window openings that respectively expose the drain region and the gate region of the trench flash memory includes forming a trench gate structure 102 on a substrate 100, forming a gate dielectric layer 104 on the trench gate structure 102, forming a select gate 106 on both a portion of the gate dielectric layer 104 which is at the sides of the trench gate structure 102 and on the substrate 100, forming spacers 108 on the side walls of the select gate 106. Afterwards, in the substrate 100, a drain region 110 is formed at two sides of the trench gate structure 102 and the selected gate 106. Furthermore, a dielectric layer 112 is formed on the substrate 100, then a photolithography and etching process is performed to create contact window openings 114 and 116 in the dielectric layer 112. The contact window opening 114 exposes a portion of the drain region 110 and the contact window opening 116 exposes a portion of the trench gate 102.
As expressed in the FIG. 1, while a misalignment or an inaccurate alignment occurs during a photolithography process, the contact window opening 114 and 116 expose not only the assigned surfaces of the trench gate structure and the drain region, but also a portion of neighbouring surface 106a next to the select gate 106. Therefore, while forming contact plugs in the contact window 114 and the 116, the contact plugs are connected to the exposed select gate 106 through abnormal electrical connection, leading to current leakage for the device, and abnormal electrical performance.

This patent is subject to a terminal disclaimer.

Method for manufacturing semiconductor devices and plug


An EUV lithography system has an EUV beam path and a monitor beam path. The EUV beam path includes a mirror system having plurality of mirror elements, the orientations of which can be changed. The monitor beam path includes a monitor radiation source, a screen and a spatially resolving detector. The mirror system is arranged in the monitor beam path between the monitor radiation source and the screen.

An EUV lithography system can be used for producing miniaturized components by virtue of a structure to be imaged, which is also referred to as mask or reticle, being imaged onto a radiation-sensitive structure, which is also referred to as resist, via EUV radiation. The EUV radiation is ultraviolet radiation, in particular with wavelengths in the region of extreme ultraviolet (EUV), such as, for example, with wavelengths in the range from 5 nm to 30 nm.
An EUV lithography system known from EP 1 202 101 A2 comprises an imaging optical unit, which is configured to image an object plane, in which a structure to be imaged can be arranged, into an image plane, in which a radiation-sensitive structure can be arranged, an EUV radiation source, and a first mirror system, which is arranged in an EUV beam path between the EUV radiation source and the object plane and which comprises a base and a plurality of mirror elements which are fixed to the base, the orientation of which mirror elements relative to the base can be set in each case in order to enable different settings of an angular distribution of the EUV radiation incident on the structure to be imaged.
The problem consists of setting the plurality of mirror elements of the mirror system relative to the base thereof or relative to another component of an optical system, into which the mirror system is integrated, or relative to an optical axis or a field plane or a pupil plane of such an optical system such that a desired setting of the angular distribution is realized and the latter is also maintained during operation of the EUV lithography system.

Monitor system for determining orientations of mirror elements and EUV lithography system


A rotary type vibration wave driving apparatus which is capable of reducing local wear of a contacting member and of reducing performance deterioration due to long term operation is provided. The apparatus includes a electro-mechanical energy conversion element, an vibration member fixed to the electro-mechanical energy conversion element and vibrated by a voltage being supplied to the electro-mechanical energy conversion element, and a moving member being brought into contact with the vibration member and frictionally driven by the vibration, and is configured such that the moving member includes a supporting portion extended from the main body portion of the moving member, and a contacting portion extended from the supporting portion and being brought into contact with the vibration member, and such that each of the supporting portion and the contacting portion is configured to be elastically deformable in the rotation axis direction of the moving member.

Generally, a vibration driven apparatus applied to a vibration wave motor has an vibration member in which vibration waves are formed, and a moving member which is brought into pressure contact with the vibration member, and obtains driving force by making the vibration member and the moving member frictionally driven by the vibration waves.
Therefore, a contacting portion arranged between the vibration member and the moving member extracts the driving force by repeating contact and separation with and from the vibration member while being deformed so as to follow the vibration of the vibration member.
A prior art form of a vibration wave motor of this kind is illustrated in FIG. 9A. (see Japanese Patent Application Laid-Open No. S61-224882). In FIG. 9A, a vibration member 122 is formed into an annular shape, and a plurality of protrusions 122b are formed in the upper portion of the vibration member 122 over the whole circumference of the vibration member 122.
A moving member 123 is brought into pressure contact with the vibration member 122 by a pressing member (not illustrated). The moving member 123 is configured by a ring-shaped main body portion 123a which is formed by an elastic member, a flange portion 123b which is extended from the main body portion 123a, and a contacting portion 123c which is extended from an end portion of the flange portion 123b and which has a friction surface that is brought into contact with the vibration member 122.
A piezoelectric ceramic 121 is bonded with an adhesive to the bottom surface of the vibration member 122, and generates traveling waves at the time when alternating voltages having a phase difference therebetween are applied to the piezoelectric ceramic 121 from a driving circuit (not illustrated) for driving the motor. When the traveling direction of the traveling waves is the positive direction of the θ direction (see the arrow in FIG. 9A), the moving direction of the frictionally driven moving member 123 becomes the negative direction of the θ direction.
In such a case of the moving member 123 configured to have the flange portion, the direction of trajectory of vibration generated in the vibration member 122 substantially coincides with the direction of displacement of the contacting portion of the moving member 123 when viewed on the plane formed by the radial direction and the vertical direction in the cylindrical coordinate system centering on the rotation axis of the moving member. When the direction of vibration trajectory substantially coincides with the direction of displacement, the sliding in the radial direction on the friction surface can be reduced to prevent deterioration of efficiency.
Further, a configuration of a moving member of a vibration wave motor in another prior art form is illustrated in FIG. 9C (see Japanese Patent Application Laid-Open No. 2002-315364).
In FIG. 9C, a plurality of contacting portions 133c which are brought into contact with the vibration member and which have predetermined spring stiffness are concentrically provided at a moving member 133.
Since the plurality of contacting portions 133c are provided, the contact area is increased, and the surface pressure of the contacting portions is reduced. Thereby, the wear of the contacting portions 133c is reduced to improve the durability of the vibration wave motor.
However, the contacting portion of the vibration wave motor of the prior art form illustrated in FIG. 9A as described above is configured to have a cantilever section having a predetermined contact width.
The contacting portion 123c of the moving member 123 is brought into contact with the vibration member 122, as illustrated in FIG. 9B.
In this case, only the vicinity of the outer diameter side edge portion of the friction surface of the contacting portion 123c is brought into contact by strong pressure with the vibration member 122, and hence the whole friction surface is not brought into uniform contact with the vibration member 122.
Therefore, even when the contact area of the contacting portion 123c is increased by simply enlarging the contacting portion 123c so as to reduce the surface pressure applied to the friction surface, for the purpose of improving the durability of the vibration wave motor, the contact area is not increased and the surface pressure is not reduced because the friction surface is brought into contact with the vibration member 122 only in the vicinity of the outer diameter side edge portion of the friction surface.
Further, when the width of the contacting portion 123c is increased, even in the case where the wear in the vicinity of the outer diameter side edge portion of the contacting portion 123c progresses and the whole friction surface of the contacting portion 123c is brought into contact with the vibration member 122, the portion of the friction surface, in which portion the direction of vibration trajectory of the vibration member 122 does not coincide with the direction of displacement of the contacting portion 123c, is increased.
This causes reduction of efficiency and generation of squealing sounds, and also causes wear. Thus, it is necessary to reduce, as a whole, the pressure force applied to the vibration member so that the friction is stabilized even at the outer diameter side edge portion of the contacting portion 123c at which the edge portion is brought into contact with the vibration member by strong pressure.
The output torque may be considered to be substantially proportional to the applied pressure force. Thus, when the applied pressure force is reduced, the output torque of the vibration wave motor is also restricted.
On the other hand, in the contacting portion 133c of the vibration wave motor of the prior art form illustrated in FIG. 9C as described above, the plurality of contacting portions are provided, and hence the contact area can be increased to improve the durability of the vibration wave motor.
Further, the direction of displacement of the respective contacting portions can be made coincident with the direction of vibration trajectory of the vibration member, so that the sliding in the radial direction on the friction surface can be reduced.
However, each of the contacting portions 133c has a cantilever section similarly to the vibration wave motor of the prior art form illustrated in FIG. 9A as described above. Thus, the local wear may be caused in dependence upon the contact state between the vibration member and the contacting portion 133c as illustrated in FIG. 9B, so as to deteriorate the performance of the vibration wave motor.
As described above, in the configuration of the contacting portion of the conventional vibration wave motor, there is a problem that the durability of the vibration wave motor is deteriorated by the local wear of the contacting portion.

Rotary type vibration wave driving apparatus


Provided are methods and devices for single-molecule genomic analysis. In one embodiment, the methods entail processing a double-stranded nucleic acid and characterizing said nucleic acid. These methods are useful in, e.g. determining structural variations and copy number variations between individuals.

Macromolecules are long polymer chains composed of many chemical units bonded to one another. Polynucleotides are a class of macromolecules that include, for example, DNA and RNA. Polynucleotides are composed of long sequences of nucleotides.
The sequence of nucleotides is directly related to the genomic and post-genomic gene expression information of the organism. Direct sequencing and mapping of sequence regions, motifs, and functional units such as open reading frames (ORFs), untranslated regions (UTRs), exons, introns, protein factor binding sites, epigenomic sites such as CpG clusters, microRNA sites, Small interfering RNA (SiRNA) sites, large intervening non-coding RNA (lincRNA) sites and other functional units are all important in assessing the genomic composition of individuals.
In many cases, complex rearrangement of these nucleotides' sequence, such as insertions, deletions, inversions and translocations, during an individual's life span leads to disease states such as genetic abnormalities or cell malignancy. In other cases, sequence differences as in Copy Number Variations (CNVs) among individuals reflects the diversity of the genetic makeup of the population and their differential responses to environmental stimuli and signals such as drug treatments. In still other cases, processes such as DNA methylation, histone modification, chromatin folding or other changes that modify DNA or DNA-protein interactions influence gene regulations, expressions and ultimately cellular functions resulting in diseases and cancer.
It has been found that genomic structural variations (SVs) are much more widespread than previously thought, even among healthy individuals. The importance of understanding genome sequence with structural variations information to human health and common genetic disease has thus become increasingly apparent.
Functional units and common structural variations are thought to encompass from tens of bases to more than megabases. Accordingly, a method that is direct, inexpensive and yet flexible of revealing sequence information and SVs across the resolution scale from sub-kilobase to megabase along large native genomic molecules is highly desirable in sequencing and fine-scale mapping projects of more individuals in order to catalog previously uncharacterized genomic features.
Furthermore, phenotypical polymorphism or disease states of biological systems, particularly in multiploidy organism such as humans, are consequence of the interplay between the two haploid genomes inherited from maternal and paternal lineage. Cancer, in particular, is often the result of the loss of heterozygosity among diploid chromosomal lesions.
Conventional cytogenetic methods such as karyotyping, FISH (Fluorescent in situ Hybridization) provided a global view of the genomic composition in as few as a single cell, they are effective in revealing gross changes of the genome such as aneuploidy, gain, loss or rearrangements of large fragments of thousands and millions bases pairs. These methods, however, suffer from relatively low sensitivity and resolution in detecting medium to small sequence motifs or lesions. The methods are also laborious, which limits speed and inconsistency.
More recent methods for detecting sequence regions, sequence motifs of interests and SVs, such as aCGH (array Comparative Genomic Hybridization), fiberFISH or massive pair-end sequencing have improved in the aspects of resolution and throughput. These methods are nonetheless indirect, laborious, expensive and rely on existing reference databases. Further, the methods may have limited fixed resolution, and provide either inferred positional information relying on mapping back to a reference genome for reassembly or comparative intensity ratio information. Such methods are thus unable to reveal balanced lesion events such as inversions or translocations.
Current sequencing analysis approaches are limited by available technology and are largely based on samples derived from an averaged multiploidy genomic materials with very limited haplotype information. The front end sample preparation methods currently employed to extract the mixed diploid genomic material from a heterogeneous cell population effectively shred the material into smaller pieces, which results in the destruction of native the crucially important structural information of the diploid genome.
Even the more recently developed second-generation methods, though having improved throughput, further complicate the delineation of complex genomic information because of more difficult assembly from much shorter sequencing reads.
In general, short reads are more difficult to align uniquely within complex genomes, and additional sequence information are needed to decipher the linear order of the short target region.
An order of 25-fold improvement in sequencing coverage is needed to reach similar assembly confidence instead of 8-10 fold coverage needed in conventional BAC and so-called shot gun Sanger sequencing (Wendl M C, Wilson R K Aspects of coverage in medical DNA sequencing, BMC Bioinformatics, 16 May 2008; 9:239). This multi-fold sequencing coverage imposes high costs, effectively defeating the overarching goal in the field of reducing sequencing cost below the $1,000 mark.
Single molecule level analysis of large intact genomic molecules thus provides the possibility of preserving the accurate native genomic structures by fine mapping the sequence motifs in situ without cloning process or amplification. The larger the genomic fragments are, the less complex of sample population in genomic samples, for example, in ideal scenario, only 46 chromosomal length of fragments need to be analyzed at single molecule level to cover the entire normal diploid human genome and the sequence derived from such approach has intact haplotype information by nature. Further, megabase-scale genomic fragments can be extracted from cells and preserved for direct analysis, which dramatically reduces the burden of complex algorithm and assembly, also co-relates genomic and/or epigenomic information in its original context more directly to individual cellular phenotypes.
In addition to genomics, the field of epigenomics has been increasingly recognized in the past 20 years or so as being of singular importance for its roles in human diseases such as cancer. With the accumulation of knowledge in both genomics and epigenomics, a major challenge is to understand how genomic and epigenomic factors correlate directly or indirectly to develop the polymorphism or pathophysiological conditions in human diseases and malignancies. Whole genome analysis concept has evolved from a compartmentalized approach in which areas of genomic sequencing, epigenetic methylation analysis and functional genomics were studied largely in isolation, to a more and more multi-faceted holistic approach. DNA sequencing, structural variations mapping, CpG island methylation patterns, histone modifications, nucleosomal remodeling, microRNA function and transcription profiling have been increasingly viewed more closely in systematical way, however, technologies examining each of above aspects of the molecular state of the cells are often isolated, tedious and non-compatible which severely circumvent the holistic analysis with coherent experiment data results.
Accordingly, there is a need in the art for methods and devices that enable single molecule level analysis of large intact native biological samples so as to enable determination of genomic and epigenomic information of a target sample. Such methods and devices would provide a very powerful tool to researchers and clinicians alike.

Methods and devices for single-molecule whole genome analysis


An electro-optic device includes: a pixel area having plural pixels; and a frame area formed in a periphery of the pixel area, on an insulating substrate, wherein the frame area includes a drive circuit driving the pixels, a control signal line to which control signals controlling the drive circuit are applied, a common potential electrode having the same potential as a common potential applied to every pixels in common, and an electrostatic protection circuit protecting the drive circuit, and the electrostatic protection circuit includes plural diodes connected in series to each other between the control signal line and the common potential electrode as well as formed by thin-film transistors.

The present disclosure relates to an electro-optic device provided with a drive circuit driving pixels on an insulating substrate such as a glass substrate and a display device having the electro-optic device.
In an active-matrix liquid crystal panel, a thin-film transistor (TFT) is used as a switching device in a pixel circuit. The TFTs are formed on the insulating substrate such as the glass substrate with pixel electrodes, signal lines, scanning lines and so on. Recently, a gate driver driving pixels is formed on the insulating substrate in the same process as a manufacturing process of the pixel circuits to thereby reduce manufacturing costs.
When forming the TFTs on the insulating substrate, there may occur electrostatic discharge damage due to electric charge locally accumulated in a subsequent process of the manufacturing process of the TFTs on the insulating substrate or after the shipping of the product. In response to this, an electrostatic protection circuit is provided between the scanning lines connected to the TFTs in the pixel circuits and a large-area common electrode (refer to U.S. Pat. No. 4,039,446 (Patent Document 1)).

Electro-optic device having an electrostatic protection circuit for protecting a gate driver and display device thereof


A versatile food appliance includes a set of hardware components common to a plurality of single-purpose food appliances. The set of hardware components is controlled by a microcontroller executing a program from a repertoire thereof stored in the general-purpose food appliance. Many processing programs are stored for operating the appliance in different modes and for processing different kinds of food by using different ingredients. Each processing program is assigned a code and can be selected by specifying the code associated with it from a control panel. The programs may be further modified parametrically by a group of process parameters. Ingredients to be used in each of the programs may be in a premixed form in a package with the code optionally labeled thereon. The repertoire of programs is updatable by the user. In the preferred embodiment, a memory card interface allows updated programs to be introduced via a removable flash memory card.

One embodiment of a food appliance in the form of a breadmaker with coding system has been disclosed in U.S. Pat. No. 5,704,277. The program-controlled machine operates according to one of a plurality of provided specified programs by receiving materials required in the specified program such as ingredients of a selected kind of bread to be baked.
Breadmakers of the type comprising a baking chamber containing an electric heater at the bottom, a baking pan which is a container to be set inside the baking chamber for receiving ingredients therein, a stirrer for stirring and kneading the ingredients inside the baking pan and a motor for rotating the stirrer in a specified manner, have been known.
Breadmakers of the type storing a plurality of programs and allowing a user to select one of them for baking a desired kind of bread have also been known. These programs generally include many complicated steps such as mixing selected ingredients and controlling the baking temperature. With some prior art breadmakers, the user is required to read a cookbook carefully to ascertain the necessary steps before setting an appropriate program.
Some breadmakers are preprogrammed, and the user has only to specify the desired kind of bread to be baked, the breadmaker automatically carrying out the program associated with the specified kind of bread.
For allowing the user to specify the kind of bread to be baked, some breadmakers are designed to display, as power is switched on, the types of bread that can be specified. An indicator is initially displayed at a default position, say, next to the name of the most commonly selected kind of bread, and the user operates a SELECT button until the indicator moves one position at a time to finally reach a position next to the desired kind of bread.
Alternatively, the breadmaker may be provided with as many push buttons as the number of different kinds of bread that can be baked thereby, and the user is required to push the button corresponding to the desired kind of bread. With prior art breadmakers, therefore, the number of programs from which the user can select one is limited because the screen of the display device is not large and the control panel of the machine cannot accommodate too many buttons.
With prior art breadmakers, furthermore, the user must carefully add the required ingredients such as flour, sugar, salt and yeast. In other words, prior art breadmakers are not energy-efficient and are difficult to use and the choice of different kinds of bread that can be baked thereby cannot be increased significantly.
Prior art breadmakers and other program-controlled appliances have a limited set of preset programs they can operate on. That is, the repertoire of programs that can be executed by a breadmaker or a similar appliance is fixed at the factory. If a new recipe calls for a different process, the user can at best approximate it by selecting the closest existing preset program. In most cases, the user will have to purchase newer models of the machine in order to have the newer features and processes.
Furthermore, prior art food processing machines tend to be task-specific and single-purpose. For example, a breadmaker is dedicated to making bread, a rice cooker for cooking rice, a rotisserie for roasting, a regular oven or a microwave oven or a convection oven for either general-purpose or specific kind of baking, toasting and broiling, etc.

Food appliance and a coding system therefor


A display system is disclosed. The display system includes a plurality of display apparatuses which are rotated in a vertical direction and disposed parallel to each other, wherein the plurality of display apparatuses may reverse and change the width and height of one received image, and may display each of the divided sub images by as many as the number of the plurality of display apparatuses, according to a location of disposition. Accordingly, the plurality of display apparatuses may display an image in the same ratio of a screen ratio of a received image without ratio readjustment or data distortion.

1. Field
Aspects of the exemplary embodiments relate to a display system and a control method thereof. More particularly, the exemplary embodiments relate to a display system composed of a plurality of display apparatuses and a control method thereof.
2. Description of the Prior Art
A video wall indicates a system embodied by disposing a plurality of display apparatuses capable of outputting an image on a plane, so that the plurality of display apparatuses are operable as if they were one display apparatus displaying an image on one large screen.
The video wall system experienced a problem that distortion can occur while an image is converted from an image customized to the size of one display apparatus, to be displayed on a plurality of display apparatuses.
That is, when an image which has been displayed on a horizontal screen is readjusted to a vertical screen, data is distorted. As shown in FIG. 1, in response to an image 100 of a horizontal screen having a 16:9 aspect ratio being rotated to a vertical screen, the image is readjusted to an image 110 whose width and height are reduced. Or, in response to the image being displayed as a full screen image 120 on a vertical screen, the ratio is not appropriate, thereby making the image difficult to understand.

Display system and control method thereof


An automatic balancing circuit for a radio frequency mixer which reduces LO-IF signal leakage, as well as minimizing second order harmonic distortion products is described. The circuit couples to in-phase and out-of-phase signal lines originating from the mixer, and comprises a differential gain network, a differential phase shift network and a combiner. The networks operate under the control of a microprocessor, which adjusts the networks so that the LO leakage signals, when combined, are almost completely eliminated.

In known spectrum analyzers, the input mixer requires hand adjustment or uses specially selected mixer diodes to reduce local oscillator ("LO") to intermediate frequency ("IF") leakage. This leakage typically limits the low frequency performance of the spectrum analyzer and introduces residual undesired signals. This mechanical balancing is expensive and does not fully reduce second harmonic distortion products.
One known circuit to reduce LO-IF leakage in a spectrum analyzer is shown in FIG. 1. The LO nulling circuit has a phase quadrature ("IQ") modulator subsystem which generates a signal equal in amplitude and opposite in phase to the undesired LO leakage signal. This signal is coupled into the IF subsystem to cancel the leakage. As the mixer for the radio frequency ("RF") input signal and the LO signal is not actually balanced, second order harmonic distortion products are not significantly reduced. As the nulling circuit requires many RF components external to the mixer itself, this circuit is simply too expensive for a low cost spectrum analyzer.

Method and apparatus for automatically balancing a radio-frequency mixer


A hollow fiber membrane module (100) of the present disclosure includes: a plurality of hollow fiber membranes (10); a binding portion (20) binding the plurality of hollow fiber membranes (10) at one end portions thereof; and a cap (30) having an internal space (30s) that communicates with each of the plurality of hollow fiber membranes (10), the cap (30) being integrated with the binding portion (20). Specifically, no other component is present between the binding portion (20) and the cap (30).

For example, for manufacturing semiconductors, a large amount of ultrapure water is indispensable. Ultrapure water is produced in a system having a hollow fiber membrane module. The hollow fiber membrane module is used in various fields, e.g., for waste water treatment, food production, and the medical field as well as production of ultrapure water.
The hollow fiber membrane module disclosed in Patent Literature 1 includes a bundle of hollow fiber membranes, a housing, a cap, and a potting material. An O-ring is disposed between the cap and the potting material. The potting material is fixed to the housing by an adhesive.


Speech segment data are encoded in accordance with their respective optimum encoding schemes. The speech segment data thus encoded are registered in a speech segment dictionary along with information specifying the encoding methods used in the encoding.

A speech synthesizing technique for synthesizing speech by using a computer uses a speech segment dictionary. This speech segment dictionary stores speech segments in units (synthetic units) of speech segments, CV/VC, or VCV. To synthesize speech, appropriate speech segments are selected from this speech segment dictionary and modified and connected to generate desired synthetic speech. A flow chart in FIG. 15 explains this process.
In step S131, speech contents expressed by kana-kanji mixed text and the like are input. In step S132, the input speech contents are analyzed to obtain a speech segment symbol string {p0, p1, . . . } and parameters for determining prosody. The flow then advances to step S133 to determine the prosody such as the speech segment time length, fundamental frequency, and power. In speech segment dictionary look-up step S134, speech segments {w0, w1, . . . } appropriate for the speech segment symbol string {p0, p1, . . . } obtained by the input analysis in step S132 and the prosody obtained by the prosody determination in step S133 are retrieved from the speech segment dictionary. The flow advances to step S135, and the speech segments {w0, w1, . . . } obtained by the speech segment dictionary retrieval in step S134 are modified and concatenated to match the prosody determined in step S133. In step S136, the result of the speech segment modification and concatenation in step S135 is output as a synthetic speech.
Waveform editing is one effective method of speech synthesis. This method, e.g., superposes waveforms and changes pitches in synchronism with vocal cord vibrations. The method is advantageous in that synthetic speech close to a natural utterance can be generated with a small amount of arithmetic operations. When a method like this is used, a speech segment dictionary is composed of indexes for retrieval, waveform data (also called speech segment data) corresponding to individual speech segments, and auxiliary information of the data. In this case, all speech segment data registered in the speech segment dictionary are often encoded using the μ-law or ADPCM (Adaptive Differential Pulse Code Modulation).
The above prior art has the following problems.
First, when all speech segment data registered in the speech segment dictionary are encoded by using an encoding scheme such as the μ-law or A-law, no sufficient compression efficiency can be obtained since each speech segment data is nonuniformly quantized using a fixed quantization table. This is so because a quantization table must be so designed that a minimum quality can be maintained for all types of speech segments.
Second, when all speech segment data registered in the speech segment dictionary are encoded using an encoding scheme such as ADPCM, the operation amount in decoding increases by the operation amount of an adaptive algorithm. This is so because the advantage (small processing amount) of the waveform editing method is impaired if a large operation amount is required for decoding.

Speech synthesis using multi-mode coding with a speech segment dictionary


A buried-waveguide light detecting element includes an n-type cladding layer on a Fe-InP substrate, a waveguide on a portion of the n-type cladding layer, and in which an n-type light guide layer, an i-light guide layer having a refractive index equal to or higher than that of the n-type cladding layer and undoped or having an impurity concentration of 1×1017 cm−3 or less, lower than the impurity concentration in the n-type light guide layer, a light absorption layer having a refractive index higher than that of the i-light guide layer, a p-type light guide layer, and a p-type cladding layer are successively layered in mesa form, from the Fe—InP substrate, and a blocking layer on the Fe—InP substrate and in which side walls of the waveguide are embedded.

1. Field of the Invention
The present invention relates to a buried-waveguide-type light receiving element and manufacturing method thereof, more particularly, to a buried-waveguide-type light receiving element used in an optical communication system or the like, and manufacturing method thereof.
2. Description of the Related Art
With the rapid increase in demand for communication, the development of communication systems of higher capacities has been pursued, which requires designing optical communication devices so as to increase the processing speed, reduce the size, improve the efficiency and reduce the manufacturing cost.
Optical communication transmission systems use light in two wavelength bands as signal light: a 1.3 μm band having a center wavelength of 1.3 μm, and a 1.55 μm band having a center wavelength of 1.55 μm.
Signal light in the 1.55 μm band has a low optical fiber loss and is used as signal light in a long-distance communication system, which is, for example, called an intercity communication (trunk system) and used for communication between large cities such as Tokyo and Osaka.
On the other hand, signal light in the 1.3 μm band has a higher optical fiber loss but has reduced wavelength dispersion and is used as signal light in a short-distance communication system, which is called in-city communication and used for communication in a large city. Signal light in the 1.3 μm band is also used in a system for communication between a base station and each home called an access system.
Light receiving elements having such a structure that signal light enters the element through a cleaved end face have been developed and mass-produced as a semiconductor light receiving element used in a receiving module of an optical communication system. Conventional semiconductor light receiving elements of this kind include a loading-type semiconductor light receiving element (see, for example, Japanese Patent Laid-Open No. 2003-332613, section [0016] and FIGS. 1, 2, and 3). In this structure, light is caused to enter a guide layer transparent to incident light on the cleaved end face and is guided to a photoelectric conversion section (light absorption layer) formed at a distance of several microns from the incidence section, and light oozing out of the guide layer in the layer thickness direction (evanescent light) is photoelectrically converted in the photoelectric conversion section. This photoelectric conversion is in an indirect form such that the concentration of photocurrents in the vicinity of the incidence end surface is reduced. This arrangement therefore has the advantage of ensuring that a reduction in response speed or breakdown of the light receiving device cannot occur easily even when a high intensity of light is input.
On the other hand, since light oozing out of the guide layer in the layer thickness direction is photoelectrically converted, obtaining high sensitivity requires a substantial waveguide length in theory. However, if the wavelength length is increased for the purpose of obtaining high sensitivity, the element capacity of the light receiving element is increased and there is a possibility of failure to achieve the desired high-speed response performance. That is, the sensitivity and high-speed response are in a trade-off relationship.
Also, there is a need to cover side surfaces of the guide layer and the photoelectric conversion section with a film of a non-semiconductor material (e.g., SiN film) having a high refractive index ratio to the materials forming the guide layer and the photoelectric conversion section in order to improve optical confinement in the guide layer and to thereby reduce loss due to radiation to portions other than the photoelectric conversion section. However, a recombination level or the like can occur easily at the semiconductor/non-semiconductor interface. In some situation, there is an anxiety about degradation of the guide layer end surface on which light is concentrated and the photoelectric conversion section to which a high electric field is applied.
Known light receiving elements proposed to solve these problems include a buried-waveguide-type light receiving element having a construction in which a waveguide layer is embedded in a Fe-doped InP (hereinafter referred to simply as Fe—InP) (see, for example, "40 Gbps waveguide type PD for mounting flip chip" Eitaro Ishimura, Masaharu Nakamichi and others, The 49th applied physics consociated lecture 2002 (Heisei 14) Spring lecture proceedings (2002.3 Tokai University), p. 1152, 27a-ZG-7).
In this construction, an optical confinement layer and a light absorption layer are embedded in Fe—InP constituted of a semiconductor and protected to ensure high reliability.
Also the element has such a structure that light directly enter the light absorption layer through a window layer. Therefore high sensitivity can be obtained even if the wavelength length is not so long, and high-sensitivity and high-speed-response characteristics can be obtained.
Another known disclosed art is a waveguide-type semiconductor light receiving element in which a 0.6 μm thick boundary layer of an n-optical confinement layer adjacent to a light absorption layer and a 0.3 pn thick boundary layer of a p-optical confinement layer adjacent to the light absorption layer are each formed as a non-doped layer (see, for example, Japanese Patent Laid-Open No. 10-303449, section [0030] and FIGS. 1 and 2).
Still another known disclosed art is a loading-type semiconductor light receiving element in which an i-InAlGaAs guide layer (wavelength composition 1.3 μm, layer thickness 0.2 μm) is formed below a light absorption layer, which has an increased depletion layer and a reduced junction capacity, and which is capable of high-speed response (see, for example, Japanese Patent Laid-Open No. 2001-168371, section [0030] and FIGS. 1 and 2).
A further known disclosed art is a waveguide-type light receiving element in which a multilayer structure having a light absorption layer p-type doped, light guide layers provided on opposite sides of the light absorption layer, the light guide layer on one side being uniformly p-type doped, the light guide layer on the other side having a low-concentration layer (e.g., an undoped layer) and an n-doped layer successively formed from the light absorption layer, is provided in mesa form on a semi-insulating InP substrate, and in which light horizontally enters the layer structure (see, for example, Japanese Patent Laid-Open No. 11-112013, sections [0004], [0008], [0009] and [0012] and FIG. 1).
Still a further known disclosed art is a semiconductor light receiving element in which an n-InGaAsP light guide layer is provided on a semi-conducting InP substrate, and a waveguide structure including an n-InP electron travel layer in mesa form, an InGaAsP layer in an undoped and n-type two-layer structure and a p-InGaAs light absorption layer (see, for example, Japanese Patent Laid-Open No. 2000-124493, sections [0004], [3008], [0009] and [0012] and FIG. 1).
Still a further known disclosed art is a waveguide-type avalanche photodiode for 40 Gbps communication (see, for example, "Waveguide-type avalanche photodiode for 40 Gbps communication" Shogo Shimizu, Kazuhiro Shiba and others, Shingaku-Giho, IEICE Technical Report OCS2006-40, OPE2006-93, LQE2006-82(2006-10), pp. 11-15).
In the conventional buried-waveguide-type light receiving element having a waveguide embedded in a Fe—InP layer, however, there is a problem that there is a possibility of mutual diffusion of a p-type dopant and Fe being caused by regrowth of the Fe—InP layer after the formation of the waveguide to cause an increase in dark current between the light absorption layer and the n-type optical confinement layer, i.e., an increase in leak current. As a method for preventing this, increasing the layer thickness of the light absorption layer is conceivable. With this method, however, there is a problem that a reduction in high-speed response and deterioration in high optical input resistance are caused.

Buried-waveguide-type light receiving element and manufacturing method thereof


In an example embodiment, a series of machine learned models are trained and utilized in conjunction with each other to improve the reliability of predictions of fuel costs. One of these models is specifically trained to learn the “gap” time for a particular retail location, meaning the amount of time between when the futures contract market price on a trading exchange making up the fuel blend has the most correlation with the retail price of that fuel blend (for that particular location). This greatly enhances the reliability of the predictions of fuel costs, and, as described in detail herein, these predictions may be used in a number of different applications in unique ways.

Fuels used for transportation play a vital role in the economy, and costs and overhead related to fuels can be a significant drag on the transportation sector specifically. Industries such as the airline industry and shipping industry rely heavily on minimizing fuel costs, although individuals also rely heavily on fuel costs, especially when planning long trips. Intelligent fuel procurement by businesses and individuals has a cascading positive impact on commerce, industry and ultimately the overall economy.
The prices of fuels and certain other commodities are difficult to predict accurately due to the presence of time shifts. Specifically, time shifts refer to the time difference between when a component of the commodity is traded on exchange and when the component is consumed in the supply chain. Fuel, for example, is commonly comprised of a blend of multiple different fuel components, each with their own national price. A fuel reseller may blend the different fuel components and then transport it to a fueling station for sale to a consumer, but this blending and transportation process takes time, and thus the price that the consumer actually pays for a fuel blend on a given day may vary based on a national price of a component that was sold several days earlier.
Machine learning may be applied to the prediction of fuel prices, and the prices of other commodities with time shifts, which allows businesses and individuals to plan commodity related activities e.g. purchases ahead of time to minimize costs, but prior art machine learning techniques, which rely upon training models in statistical ways and then utilizing those models, produce unreliable results when performing such predictions. What is needed is an improved modelling and training based on supply chain and use of machine learning techniques to make such predictions more reliable.

Machine learned models for items with time-shifts


An alarm system and method for (1) assisting a user in arming and disarming an alarm system when locking and unlocking an entry door, (2) automatically locking an entry door when arming the alarm system, and/or (3) remotely controlling an electronic lock in an entry door.

Occupants of a home usually arm their home's alarm system when they are away from their home or when they are retired for the evening. Most other times the alarm system is disarmed. When the alarm system determines that an intruder has invaded the home, it sounds a local alarm and notifies a remote central control station of the intrusion. The central control station consequently sends security personnel to investigate the intrusion. The occupants of a home feel safe knowing that if the alarm has not sounded, there has been no intrusion into their home. If the alarm has sounded, security personnel are on their way to the home.
Problems arise when the system is not properly armed and disarmed. Typical problems users have include not disarming the system before the alarm sounds and the central control station is notified. This may occur when the user unlocks and enters the home but becomes distracted or takes too long before entering the disarm code into the alarm system keypad. Another common mistake users make is not arming the alarm system when the home is unoccupied. This may occur when the user simply forgets to arm the alarm system possibly due to exiting a door that is not near the alarm system keypad. Having an alarm system that allows the user to use a single action to unlock an entry door and disarm the alarm system or lock the entry door and arm the alarm system would eliminate these problems.
Another problem that may occur is the user may forget to lock an entry door after leaving or entering the home. If the user is home, he may arm the alarm system and think his home is secure. Having an alarm system that locks the doors when the system is armed eliminates this problem. An alternative solution is to prevent the alarm system from arming if a door is unlocked. In this solution, when the user tries to arm the alarm system but is unable to, he will know a door is unlocked (or open). If the user is away, he may worry that he has forgotten to lock the entry door. Having an alarm system that allows the user to remotely communicate to his alarm system to lock the entry door to his home would solve this problem. An additional user problem may occur when he is locked out of the house. Having an alarm system that allows the user to unlock the entry door remotely would solve this problem.
It is therefore an object of the present invention to provide an alarm system that disarms the alarm system when the entry door is unlocked.
It is a further object of the present invention to provide an alarm system that arms the alarm system when the homeowner locks the entry door.
It is a further object of the present invention to provide an alarm system that locks the entry door when the homeowner arms the alarm system.
It is a further object of the present invention to provide an alarm system that prevents the homeowner from arming the alarm system when the entry door is not locked.
Finally it is a further object of the present invention to provide an alarm system that unlocks or locks the entry door remotely.

Door entry security device with electronic lock


A leech trap consisting of a location marking float and an enclosure having a removable lid and a first plurality of holes through the surface of the enclosure to allow entry of leeches into the enclosure. The lower end of the enclosure is weighted and contains a second plurality of smaller holes for rapid drainage of water without loss of the trapped leeches.

1. Field of the Invention
This invention relates to fishing equipment, and more particularly to unattended leech traps for the capture of live leeches.
2. Description of Related Art
Historically, bait harvesters trapped leeches using coffee cans, burlap sacks, aluminum tubes, or metal folding traps. The harvester would bait one of these traps with frozen fish parts or a piece of liver from a chicken, cow, or pig. A typical technique was to place the baited trap in the water in the early evening, check the trap in the early morning, and rotate the traps between several locations known to produce leeches.
Prior art leech traps have the disadvantage that they corrode or degrade due to the long time they spend underwater. Burlap or other sacks tend to break down over time under water. Metal traps, such as coffee cans or aluminum tubular or folding traps rust or corrode from contact with water. A further disadvantage of prior art leech traps is that it is relatively difficult to remove the trapped leeches from the traps. Leeches readily adhere to cloth sacks. When a metal trap is new, leeches do not readily adhere to the sides or bottom of the trap, however as the trap corrodes the leeches adhere more and more tightly to the surface of the trap.
Known prior art leech traps include U.S. Des. Pat. No. 420,417 to Daniels. The Daniels leech trap structure includes a substantially cylindrical leech trap enclosure perforated by numerous holes. The Daniels leech trap does not disclose a trap having larger holes in the upper portion and smaller holes in the lower portion, nor does it disclose a weighted lower portion to ensure proper orientation during use. The Daniels leech trap also does not disclose or suggest the use of a location marking float to allow unattended use on shore or from a boat.


A liquid crystal display (“LCD”) having a plurality of gray voltages with varying magnitudes and a driving method thereof. An LCD includes a reference voltage generator changing level of a supply voltage based on a first signal to generate a reference voltage. The first signal varies depending on the surrounding brightness of the LCD, the brightness of the on-screen images of the LCD, and user's manipulation. The LCD also includes a gray voltage generator generating a plurality of gray voltages with magnitudes varying dependent on the magnitude of the reference voltage and a predetermined voltage such as a ground voltage. The LCD further includes a plurality of gate lines transmitting a plurality of gate signals, a plurality of data lines transmitting the gray voltages, and a plurality of pixels. Each pixel has a switching element connected to one of the gate lines and one of the data lines and transmitting the gray voltages to the pixels under the control of the gate signal. The LCD includes a gate driver supplying the gate signals to the gate lines and a data driver selecting the gray voltages based on gray data from an external source to supply to the pixels via the data lines.

(a) Field of the Invention
The present invention relates to a liquid crystal display and a driving method thereof, and particularly to a liquid crystal display having a plurality of gray voltages with varying magnitudes and a driving method thereof.
(b) Description of the Related Art
A typical liquid crystal display ("LCD") includes a pair of panels with field-generating electrodes and a liquid crystal layer with dielectric anisotropy interposed therebetween. The liquid crystal layer is applied with electric field generated by the field-generating electrodes, and the transmittance of light passing through the liquid crystal layer is adjusted by controlling the magnitudes of voltages applied to the field-generating electrodes, thereby obtaining desired images.
Generally, a dark image of a display is much unclear at a bright place than at a dark place. This is because human eyes hardly recognize the brightness difference between portions of a dark image at a bright place. Since the brightness difference between low grays of a conventional LCD is small, the visibility of LCD images, specifically for a motion picture, is inferior to that of other kinds of displays.
In order to improve brightness difference between low grays, it is suggested to improve a light source of an LCD such as a backlight unit. For example, the light intensity of lamps of the backlight unit is increased, the number of the lamps is increased, or several various prism sheets are provided in the backlight unit. However, these increase the power consumption, the weight and the cost of the LCD.
In addition, it is hard to increase the light intensity of the backlight unit twice, three times or more than the normal intensity, and even though the intensity would increase, the visibility is not so much improved in comparison with the increasing rate of the intensity of the backlight unit. Furthermore, a bright screen makes users feel fatigue soon.

Liquid crystal display having gray voltages with varying magnitudes and driving method thereof


A fire safety interior door marker including a plate with a front side and a rear side. The front side has a reflective surface area and a tactile surface area. The rear side of the plate is provided with an adhesive backing, normally covered by a release sheet, for securing the plate to an exit door or beneath a window Also disclosed is a method for visually and tactually indicating the location of an escape door or window for use during a fire in a building.

The present invention relates generally to an emergency window or door exit marker. More particularly this invention relates to a fire safety window or interior door marker for identifying emergency windows or door exits in the event of a fire emergency for safe escape of inhabitants therein.
Loss of life which occurs because of fire in a home or building is often caused not by the fire or flames but instead by the subsequent smoke and toxic gases that ar produced. Occupants of a building on fire are often disorientated from the smoke and are unable to find a safe exit. They often find themselves trapped in a closet, bathroom or in a corner of a room where they fall victim to smoke inhalation. The National Fire Protection Association states that if one must exit through smoke, the cleanest air will be several inches off the floor and one should crawl on their hands and knees to the nearest safe exit.
A number of devices have been disclosed for directing occupants of a building toward an exit. For example, U.S. Pat. No. 3,665,626 granted to Lund et al., discloses the commonly observed exit sign. The exit sign generally includes a light transmitting visual image of the word "EXIT" in capital letters with light transmitting visual images of arrows underneath pointing in the appropriate direction toward the nearest exit door or stairway. U.S. Pat. No. 2,480,584 granted to Kohlhauer et al., discloses a luminous and luminescent sign which can be adapted to display the letters "EXIT" for visually directing one to an exit. Instead of light transmitting signs, light reflective plates and composite contrast color embedded displays, U.S. Pat. No. 3,973,342 granted to Gubela and U.S. Pat. No. 3,506,528 granted to Dean, respectively, can also be configured as exit signs. So far as is known these signs are typically installed in the halls of office buildings, schools, hotels, etc., attached to the ceiling where smoke naturally rises and accumulates rendering these devices inoperable and thus ineffective during a fire.
Further, a number of fire safety escape route markers have been devised for directing occupants in a hallway to a safe exit in the event of a fire. For example, U.S. Pat. No. 4,385,586 granted to Schriever, discloses an escape route rescue system which employs a series of devices, each of which has tactile characteristics of shape and surface contacts in combination which attach to the middle and lower part of the wall to indicate direction and distance to the nearest evacuation exit. The generally arrow shaped member provides directional information and contact points provide distance information. The device is also capable of luminescence to aid in visual as well as tactile reference.
Another example, U.S. Pat. No. 4,401,050 granted to Britt et al., discloses a phosphorescent escape route indicator which has an adhesive back for attaching to an escape route wall above the floors and stairways. The directional indicators are shaped like arrows which project outwardly or are otherwise raised or embossed to allow the same to be felt even after the phosphorescent glow disappears.
Also of interest is U.S. Pat. No. 259,544 granted to Howard which discloses a means for facilitating speedy exit from buildings in case of fire or alarm which has a tactile means in the form of a rail for guiding a person to an exit.
In theory, these devices provides a system for directing the occupant of a burning building to a safe exit, however, they are also cumbersome and confusing. Specifically, the markers are numerous, and in the event of a real emergency the occupant would be less likely to decipher the direction or, as in Schriever, decipher the contact points determining the number of doors to the true safe exit door without undue waste of time. In the case of dense smoke, if a trapped occupant uses the markers to determine direction by touch, he or she would have to pass by the exit door in order to determine that the markers point in the opposite direction on the other side of the door, thus increasing the time one would need in order to escape. In the event of a fire emergency, every second is critical and the delay of even a split second could be fatal to the occupant trapped inside.
However, there is still a need for a simple and effective marking device for directing a trapped occupant of a bedroom, office, hospital room, hotel room, classroom, etc., of a burning structure, to a safe exit door or window whether or not there is sufficient ambient light.

Fire safety window and interior door marker


A process for fabricating ohmic contacts in a field-effect transistor includes the steps of: thinning a semiconductor layer forming recessed portions in the semiconductor layer; depositing ohmic contact over the recessed portions; and heating the deposited ohmic contacts. The field-effect transistor comprises a layered semiconductor structure which includes a first group III nitride compound semiconductor layer doped with a charge carrier, and a second group III nitride compound semiconductor layer positioned below the first layer, to generate an electron gas in the structure. After the heating step the ohmic contacts communicate with the electron gas. As a result, an excellent ohmic contact to the channel of the transistor is obtained.

1. Field of the Invention
The present invention relates generally to fabrication processes for transistors. More particularly, it relates to a process for fabricating ultra-low contact resistances in GaN (Gallium Nitride)-based heterojunction field-effect transistors (HFETs).
2. Description of the Related Art
Recent rapid progress in GaN HFET technology provides convincing evidence that this technology will ultimately have a big impact on a wide range of systems, including future generation radar and satellite communications systems. See, for example, U.S. Pat. No. 6,100,548 relating to modulation-doped field-effect transistors and fabrication processes and U.S. Pat. No. 5,766,695 relating to a method for reducing surface layer defects in semiconductor materials having a volatile species.
FIG. 1 shows a cross section of a conventional GaN-based HFET structure, indicated with 1. This structure includes a first semiconductor layer 2 which has a first band gap and is doped with a charge carrier (e.g., an N-type dopant in the form of silicon). Usually this layer 2 is Al0.15Ga0.85N and is approximately 200 angstroms thick. This layer is a donor layer and is doped to have an electron density in the range of 1-2×1018 cm−3. The structure 1 also includes an undoped second semiconductor layer 3 positioned below the first semiconductor layer 2. The second semiconductor layer 3 has a second band gap that is less than the first band gap. This second layer is undoped GaN with a thickness of about 2 micrometers and generates a two-dimensional electron gas 4 in the semiconductor structure 1. A third semiconductor layer 5 is positioned between the first and second semiconductor layers 2 and 3. This "spacer" layer 5 is undoped. Although it decreases the carrier density in the two-dimensional electron gas 4, it further enhances the carrier mobility. The spacer layer 5 is Al0.15Ga0.85N and is about 30 angstroms thick.
A source ohmic contact 6 and a drain ohmic contact 7 are formed on top of the structure 1. The ohmic contacts 6, 7 are generally fabricated by evaporating a metal system of titanium, aluminum, nickel and gold (Ti/Al/Ni/Au) onto the layered semiconductor structure 1. The preferred ratios for those elements are Ti=6%, Al=65%, Ni=13%, and Au=16%. This metal system is then alloyed at an elevated temperature (e.g., 900° C.) so that it penetrates the layered semiconductor structure 1 (as indicated by broken lines 8) and communicates with the two-dimensional electron gas 4.
The breakdown voltage (from drain to source) of the HFET structure would be degraded if the ohmic contacts 6, 7 directly contacted the highly doped first semiconductor layer 2. Accordingly, a cap layer 9 is usually carried over the first semiconductor layer 2 and the ohmic metal system of these contacts is evaporated on this cap layer. The cap layer is Al0.15Ga0.85N and has usually the lightest doping that can be fabricated. This doping level is typically referred to as an unintentional doping (UID) level because some doping will inevitably be present.
An e-beam resist 10 is also formed over the layered semiconductor structure 1. A gate pattern is written into the resist 10 with an e-beam and, subsequently, a metallic gate 11 is evaporated into the gate pattern. The first and second semiconductor layers 2 and 3, the spacer layer 5, the ohmic contacts 6 and 7 and the cap layer 9 are carried on an insulating substrate 12, for example sapphire with a thickness of about 250 micrometers.
The fabrication process of GaN devices is a fundamental step for the viability of GaN device technology. In particular, the ability to make low and reproducible ohmic contacts to the channel of the GaN device is of utmost importance. Low ohmic contact resistance is crucial for high-performance devices. Lower contact resistance results in higher speed and gain for the device. Resistive heating is also reduced, therefore increasing reliability and efficiency. High efficiency is a key requirement for power devices. Reproducibility of the contact resistances is also a critical requirement for manufacturability, particularly for MMIC (monolithic microwave integrated circuit) fabrication.
In the GaN HFET structure above described, the ohmic contacts 6, 7 are created by depositing a metalization stack on the surface of the semiconductor, and by subsequently applying an annealing process to alloy the metal with the semiconductor. This approach works very well for GaAs and InP-based materials and devices. However, for GaN-based materials, this approach yields high contact resistances because the presence of the wide band-gap barrier layer, AlGaN, inhibits the ohmic metals from diffusing into the channel and forming proper contacts. Conventional alloy contacts in GaN-based HFET devices usually result in a contact resistance of 2.0 Ω/mm. This contact resistance is ten times the value of contact resistances of GaAs-based devices.

Process for fabricating ultra-low contact resistances in GaN-based devices


An electric control apparatus for an ice making machine includes an initial water supply cycle control device for opening a water valve for a predetermined time, and a water level sensor mounted within a water tank for detecting whether or not a level of water in the water tank is more than a predetermined level. A first check-up device is provided for permitting operation of a defrost/water supply cycle and an ice making cycle when the level of water in the water tank exceeds the predetermined level after an initial water supply cycle is conducted under control of an initial water supply control device. The first check-up device also repeats operation at the initial water supply cycle when the level of water in the water tank is less than the predetermined level. A second check-up device permits operation of the ice making cycle when the level of water in the water tank exceeds the predetermined level after the defrost/water supply cycle, and repeats operation at the initial water supply cycle when the level of water in the water tank is less than the predetermined level after the defrost/water supply cycle.

1. Field of the Invention
The present invention relates to an ice making machine in which ice cubes are automatically produced by alternate operation at a defrost/water supply cycle and an ice making cycle, and more particularly to an electric control apparatus for the ice making machine in which a countermeasure is taken for shortage of ice making water in a water tank caused by suspension of the service water.
2. Description of the Prior Art
As disclosed in Japanese Utility Model Publication No. 64-2137, a conventional ice making machine of this kind is designed to repeatedly conduct a defrost/water supply cycle and an ice making cycle for automatically producing ice cubes, to detect whether or not a sufficient amount of water is stored in a water tank at the end of the defrost/water supply cycle, and to prohibit the ice making cycle if a sufficient amount of water is not stored in the water tank and repeatedly conduct the defrost/water supply cycle. During operation of the ice making machine at the defrost/water supply cycle, however, a compressor is activated and a hot gas valve is opened. Accordingly, if the water tank may not be supplied with fresh water due to suspension of the service water, electric power is uselessly consumed, and the compressor can become overheated.

Electric control apparatus for ice making machine


A sensing apparatus (20) based on fiber optics including fiber gratings for monitoring stator slot temperatures in an electromotive machine (10) is provided. The apparatus may include a dielectric strip (22) to be received in a gap between a first stator bar (16) and a second stator bar (18) in a stator slot (14). One or more optical fibers (24, 25) may be disposed in the dielectric strip and extend along a longitudinal axis of the dielectric strip. A plurality of sites 28 in the optical fiber include a respective fiber Bragg grating arranged to have a respective optical response in a wavelength spectrum indicative of a value of temperature at the grating site.

An electromotive machine, such as a large electrical generator as may be used in the field of electrical power generation or a motor, includes a stator winding having a large number of conductors or stator bars that are pressed into slots in a base body, such as a laminated stator core. Such a machine represents a very expensive and long-term investment. For example, a failure of the generator not only endangers the power equipment itself but may also result in substantially costly and burdensome service reduction due to the down time associated with a repair. Cost-effective, reliable and accurate monitoring of stator slot temperatures is desirable for timely and systematic prevention of malfunctions. For example, this monitoring may be desirable for determining the operational condition of the machine and/or for analyzing the design of the stator bars. Disclosed embodiments are believed to successfully address at least such needs.

Fiber optic sensing apparatus for detecting stator slot temperatures and stator including such apparatus


The present inventions are directed to portable cleaning apparatuses adapted for use on mobile cleaning carts useable, for example, for cleaning hospital rooms. Each apparatus comprises a pre-filter module, a vacuum source module, and a secondary filter module, releasably securable to one another, the entire apparatus being configured provide high efficiency cleaning at low noise levels.

Traditional methods for cleaning institutional spaces, generally, and a patient's area in a medical facility, specifically, include dry mopping and dusting. Such methods can disperse dust particulates throughout the patient's environment, decreasing air quality. The dust particulates also resettle and contaminate surfaces thought to be clean. Airborne dust could also be breathed by the patient, leading to infections and lowering health quality. Traditional cleaning methods have also included mopping floors using a bucket that is moved from room to room without changing or refreshing the cleaning solution. This approach can lead to cross contamination of bacteria from one room to the next.
Portable mobile carts are available for use in cleaning hospital environments. In some cases, these portable carts may include a shelf for a portable vacuum cleaner. These portable vacuum cleaners take up valuable space otherwise useful for carrying other cleaning supplies.
There is a need for vacuum cleaning systems which can be mounted or contained with mobile cleaning carts and provide a much smaller spatial footprint, while maintaining the high efficiency cleaning and acoustical performance needed for use in institutional, including hospital, environments.


A method and protocol to create and control compositions on a remote device is disclosed. The protocol allows servers and other devices to take advantage of processing capabilities of remote devices to render compositions on the remote devices, thereby increasing server scalability and leveraging the remote device processing capabilities. The protocol provides high-level command packets to communicate resource command packets and control packets to the remote device with the payload having the information needed to process the commands.

Digitally based multimedia, the combination of video and audio in a digital format for viewing on a digital device, and digital media such as images and animation is rapidly increasing in capacity and proliferation. Nearly every new personal computer manufactured today includes some form of multimedia. Sales of digital products such as cameras, video recorders, phones and televisions are steadily increasing. Multimedia is also becoming increasingly prevalent in the Internet realm as the growth of the Internet steadily and rapidly continues. Continued advances in these computer-based technologies have lead to not only increased performance, but also increased performance expectations by the users of such computer equipment. The industry has responded with increased speed for CD ROM drives, communication modems, and faster video and audio cards. These increased user expectations extend not only to hardware capability, but also to the processing capability of data.
For example, in areas such as multimedia and audio compression, data is processed so that it can be processed as a steady and continuous stream. This data is used in areas such as video conferencing, gaming, digital video discs (DVD), professional audio, telephony, and other areas where audio, video, or audio and video is digitally processed.
Rendering data almost always requires some form of processing among various modules in a system. For example, a video clip might require decoding in a dedicated hardware module, rasterizing the video fields in another hardware module, digital filtering of the audio in a software module, insertion of subtitles by another software module, parsing audio data to skip silent periods by a software module, etc. For streaming to work, the data must be processed as a steady stream and then rendered to audio and/or video. If the data isn't processed quickly enough, however, the presentation of the data will not be smooth.
In conventional client-server rendering, the data is processed at the server and sent in discrete virtual frames to the client where the frames are rendered. Each frame contains the entire data and information needed to render the frame, even if there is no change in the item being rendered. For example, every animation frame has the full amount of data and information to render the frame even if the frame is identical to an adjacent frame. As a result, the transmission of the data consumes a large amount of available bandwidth. This bandwidth consumption reduces the number of clients a server can support. Additionally, hardware on a client machine cannot be taken advantage of to process the data. For example, the server in processing the data does not have the ability to use the hardware features of client hardware such as 3D graphic accelerators.