Abstract: Provided are a semiconductor device which shows excellent negative differential conductance or negative transconductance and is manufactured without a complicated manufacturing process and a method of manufacturing the same. The semiconductor device includes a channel layer serving as a conduction region and a floating region electrically separated from the channel layer. Provided between the channel layer and the floating region is a quantum well layer constituted with a pair of barrier layers and a quantum well layer sandwiched between the pair of barrier layers. A source electrode and a drain electrode are electrically connected to the channel layer. A gate electrode is provided in an opposite position from the well layer in the floating region. When changing a drain voltage relative to a predetermined gate voltage, drain current characteristics show negative differential conductance.

Abstract: A semiconductor device of the present invention comprises Al0.3Ga0.7N layer 4 and Al0.1Ga0.9N layer 5 having different Al contents as an electron supply layer on GaN layer 6 serving as an active layer. An area where Al0.3Ga0.7N layer 4 is formed is used as a low resistance area, while an area where Al0.1Ga0.9N layer 5 is formed is used as a high resistance area. As a result, a distribution of two-dimensional electrons serving as carriers is produced within a horizontal plane perpendicular to the thickness direction of the layers to form a desired device configuration. For example, when the configuration is applied to a transistor configuration, a channel concentration under a gate is reduced to improve withstand voltage between the gate and a drain, and at the same time, a channel concentration in source and drain areas is increased to realize low contact resistance.

Abstract: A structure for preveting MMICs (Monolithic Microwave Integrated Circuits) from the deterioration in the high-frequency transmission characteristics thereof, which is resulted from mechanical pressure applied to the pads during the wire-bonding thereto for external connection. The structure includes a groove provided in the surface of the interlayer insulation film around each of the pads. The line conductor for transmitting high-frequency signals is free from the peeling off or bending thereof, which is caused by the deformation in the interlayer insulation films during when the mechanical pressure applied to the pads, and thus, the change in the transmission characteristics of the line conductor can be minimized, and the reliability of MMICs can be improved.

Abstract: A CMOS inverter having a heterostructure including a Si substrate, a relaxed Si1−xGex, layer on the Si substrate, and a strained surface layer on said relaxed Si1−xGex, layer; and a pMOSFET and an nMOSFET, wherein the channel of said pMOSFET and the channel of the nMOSFET are formed in the strained surface layer. Another embodiment provides an integrated circuit having a heterostructure including a Si substrate, a relaxed Si1−xGex, layer on the Si substrate, and a strained layer on the relaxed Si1−xGex, layer; and a p transistor and an n transistor formed in the heterostructure, wherein the strained layer comprises the channel of the n transistor and the p transistor, and the n transistor and the p transistor are interconnected in a CMOS circuit.

Abstract: A partially-depleted Silicon-on-Insulator (SOI) substrate with minimal charge build up and suppressed floating body effect is disclosed, as well as a simple method for its fabrication. A thin Si/Ge epitaxial layer is grown between two adjacent epitaxial silicon layers of a SOI substrate, and as part of the silicon epitaxial growth. The thin Si/Ge epitaxial layer introduces misfit dislocations at the interface between the thin Si/Ge epitaxial layer and the adjacent epitaxial silicon layers, which removes undesired charge build up within the substrate.

Abstract: The MOS field-effect transistor aims to enhance the electron mobility and the hole mobility in the channel portion by employing the strained-Si/SiGe (or Si/SiGeC) structure. Crystallinity of such a heterostructure is maintained in a preferable state, shortening of the effective channel length is prevented, diffusion of Ge is prevented and the resistance of the source layer and the drain layer is reduced. The channel region has a layered structure formed by stacking the Si layer and, the SiGe or SiGeC layer in order from the surface. The source layer and the drain layer formed of SiGe or SiGeC including high concentration impurity atoms providing a desired conduction type, are in contact with both end surfaces of the channel region. The surfaces of the source layer and the drain layer have a shape rising upwardly from the bottom portion of the gate electrode.

Abstract: An across-wafer optical MEMS device includes a protective lid having across-wafer light-transmissive portions. The across-wafer optical MEMS device allows light to pass in a direction substantially parallel to a surface on which the optical MEMS device is mounted. The light-transmissive portions in the protective lid allow light to pass from an optical device located on one side of the optical MEMS device to a second device located on another side of the optical MEMS device. A plurality of optical MEMS devices can be located on the substrate and enclosed by the same lid without wafer-level encapsulation of each optical MEMS device.

Abstract: The present invention is for an improved modulator and detection device that use reversed biased diodes containing not intentionally doped (NID) optically active regions sandwiched between conductive layers of p-doped and n-doped semiconductor layers. A photo-current is generated using the optical non-linearity of multiple quantum structures inside the active region and that can be used in an external circuit to provide feedback to the device itself. This is commonly referred to as the self electro-optic effect device (SEED) where the applied electric field modulates the absorption (excitonic in nature due to the reduced dimensionality of the quantum well) of the active layer by the use of the quantum confined Stark effect. The present invention seeks to improve on known devices by separating the photo-current from the perpendicular biased electric field so as to produce a four electrical port device, by simultaneously applying non-parallel fields.

Abstract: An ovonic phase-change semiconductor memory device having a reduced area of contact between electrodes of chalcogenide memories, and methods of forming the same. Such memory devices are formed by forming a tip protruding from a lower surface of a lower electrode element An insulative material is applied over the lower electrode such that an upper surface of the tip is exposed. A chalcogenide material and an upper electrode are either formed atop the tip, or the tip is etched into the insulative material and the chalcogenide material and upper electrode are deposited within the recess. This allows the memory cells to be made smaller and allows the overall power requirements for the memory cell to be minimized.

Abstract: A semiconductor device operable with a single positive power source, enabling an increase in efficiency, and improved in high-frequency characteristics by lowering the resistivity of a gate contact, including a carrier run layer formed on a substrate for running of carriers; a carrier supply layer formed on the carrier run layer, having a larger bandgap than the carrier run layer, and containing a first conductivity type impurity; a barrier layer formed on the carrier supply layer and having a smaller bandgap than the carrier supply layer; a source electrode and a drain electrode formed on the barrier layer at a predetermined distance from each other; a gate electrode formed on the barrier layer between the source electrode and the drain electrode away from the source electrode and the drain electrode; and a first low resistivity region formed at least below the gate electrode in the barrier layer and containing a second conductivity type impurity opposite in conductivity to the first conductivity type, and a

Abstract: There is provided a compound semiconductor device having a MESFET whic comprises a channel layer made of InxGa1-xPySb1-y (where 0.3<x<0.7, 0.9<y<0.999999) formed by doping an impurity onto a substrate, a barrier layer formed on the channel layer, a gate layer formed on the barrier layer, and a source electrode and a drain electrode formed separately on both sides of the gate electrode on the barrier layer. Accordingly, the mutual conductance of the compound semiconductor device having the MESFET can be increased rather than the prior art.

Abstract: A GaN-based HFET includes a set of layers all having a common face polarity, i.e., all being either Ga-face or N-face. One of the layers is a thin barrier layer having a first face with a positive charge and a second face with a negative charge thereby causing a potential change to occur between the two faces. The if potential change causes the barrier layer to prevent electron flow from a channel layer into a buffer layer. The GaN-based HFET may also be fabricated without a top barrier layer to obtain an inverted GaN-based HFET.

Abstract: A method and a layered heterostructure for forming p-channel field effect transistors is described incorporating a plurality of semiconductor layers on a semiconductor substrate, a composite channel structure of a first epitaxial Ge layer and a second compressively strained SiGe layer having a higher barrier or a deeper confining quantum well and having extremely high hole mobility. The invention overcomes the problem of a limited hole mobility for a p-channel device with only a single compressively strained SiGe channel layer.

Abstract: A semiconductor substrate, a field effect transistor, a method of forming a SiGe layer and a method of forming a strained Si layer using the same, and a method of manufacturing a field effect transistor are provided, which enable the threading dislocation density of the SiGe layer to be reduced and the surface roughness to be minimized. On top of a Si substrate 1 is provided a SiGe buffer layer 2, 12 constructed of a plurality of laminated layers comprising alternating layers of a SiGe gradient composition layer 2a, 12a in which the Ge composition ratio increases gradually from the Ge composition ratio of the base material, and a SiGe constant composition layer 2b, 12b which is provided on top of the gradient composition layer and in which the Ge composition ratio is equal to that of the upper surface of the gradient composition layer.

Abstract: A high voltage microwave field effect transistor (FET) and method for its manufacture. The FET (10) includes a channel layer (18) formed of compressively strained GaInP. Carrier confinement layers (16), (20) formed of tensile strained (AlGa)InP are formed both above (20) and below (16) the channel layer (20) to confine the carriers to the channel layer (20) and to provide a high breakdown voltage.

Abstract: A transistor having an electron quantum-wave interference layer with plural periods of a pair of a first layer W and a second layer B in a p-layer of a pn junction structure. The second layer B has wider band gap than the first layer W. Each thicknesses of the first layer W and the second layer B is determined by multiplying by an odd number one fourth of quantum-wave wavelength of carriers in each of the first layer W and the second layer B, the carriers existing around the lowest energy level of the second layer B. The quantum-wave interference layer functions as an electron reflecting layer, and enables to lower a dynamic resistance of the transistor notably. An amplification factor of a bipolar transistor of an npn junction structure, having the electron reflecting layer is improved compared with a transistor without an electrode reflecting layer. Similarly, a transistor having a hole reflecting layer, which has a larger amplification factor, can be obtained.

Abstract: A method for producing a composite structure for microelectronic devices includes producing several microelectronic devices by means of a deposition method, preseeding a surface with growth seeds for a diamond and depositing the diamond layer from a gas phase. The diamond layer is provided with thin spots between the devices. According to the invention, the devices are laid down initially on a growth substrate directly and/or with the use of the material of the growth substrate. Following the deposition of the devices, the latter are seeded on their free surfaces for the diamond layer. The diamond layer is located on the seeded free surfaces of the devices.

Abstract: A single-electron memory device using the electron-hole Coulomb blockade is provided. A single-electron memory device in accordance with an embodiment of the present invention includes a plurality of quantum dot tunnel-junction arrays, a gate electrode, and source and drain electrodes. The plurality of quantum dot tunnel-junction arrays include at least two tunnel-junctions, are parallelly coupled to each other, and are well separated from each other to prevent single-electron tunneling between them. One of the plurality of quantum dot tunnel-junction arrays includes the gate electrode, and the voltage applied to the gate electrode can vary the number of electron-hole pairs.

Abstract: A semiconductor structure and a method of forming same is disclosed. The method includes forming, on a substrate, an n-doped collector structure of InAs/AlSb materials; forming a base structure on said collector structure which base structure comprises p-doped GaSb; and forming, on said base structure, an n-doped emitter structure of InAs/AlSb materials. The collector and emitter structure are preferably superlattices each comprising a plurality of periods of InAs and AlSb sublayers. A heterojunction bipolar transistor manufactured using the method is disclosed.

Abstract: An MIS device (20) includes a semiconducting substrate (22), a silicon nitride buffer layer (24), a ferroelectric metal oxide superlattice material (26), and a noble metal top electrode (28). The layered superlattice material (26) is preferably a strontium bismuth tantalate, strontium bismuth niobate, or strontium bismuth niobium tantalate. The device is constructed according to a preferred method that includes forming the silicon nitride on the semiconducting substrate prior to deposition of the layered superlattice material. The layered superlattice material is preferably deposited using liquid polyoxyalkylated metal organic precursors that spontaneously generate a layered superlattice upon heating of the precursor solution. UV exposure during drying of the precursor liquid imparts a C-axis orientation to the final crystal, and results in improved thin-film electrical properties.

Abstract: An ovonic phase-change semiconductor memory device having a reduced area of contact between electrodes of chalcogenide memories, and methods of forming the same. Such memory devices are formed by forming a tip protruding from a lower surface of a lower electrode element. An insulative material is applied over the lower electrode such that an upper surface of the tip is exposed. A chalcogenide material and an upper electrode are either formed atop the tip, or the tip is etched into the insulative material and the chalcogenide material and upper electrode are deposited within the recess. This allows the memory cells to be made smaller and allows the overall power requirements for the memory cell to be minimized.

Abstract: A semiconductor device includes: a substrate; a buffer layer including GaN formed on the substrate, wherein surfaces of the buffer layer are c facets of Ga atoms; a separating layer including (InXAl1-X)YGa1-YN (where 0≦X≦1, 0≦Y≦1) formed on the buffer layer, wherein surfaces of the separating layer are c facets of In, Al, or Ga atoms; a channel layer including GaN, InGaN, or a combination of GaN and InGaN formed on the separating layer, wherein surfaces of the channel layer are c facets of Ga or In atoms; and an electron supply layer including AlGaN formed on the channel layer, wherein surfaces of the electron supply layer are c facets of Al or Ga atoms, wherein the AlN composition ratio in the separating layer is smaller than the AlN composition ratio in the electron supply layer.

Abstract: A semiconductor device includes: a substrate; a buffer layer including GaN formed on the substrate, wherein: surfaces of the buffer layer are c facets of Ga atoms; a channel layer including GaN or InGaN formed on the buffer layer, wherein: surfaces of the channel layer are c facets of Ga or In atoms; an electron donor layer including AlGaN formed on the channel layer, wherein: surfaces of the electron donor layer are c facets of Al or Ga atoms; a source electrode and a drain electrode formed on the electron donor layer; a cap layer including GaN or InGaAlN formed between the source electrode and the drain electrode, wherein: surfaces of the cap layer are c facets of Ga or In atoms and at least a portion of the cap layer is in contact with the electron donor layer; and a gate electrode formed at least a portion of which is in contact with the cap layer.

Abstract: A high electron mobility transistor including an n-type semiconductor layer having a mixed crystal of aluminum gallium arsenide with an aluminum mixed ratio set to fall in the range of 0.2˜0.3, and an undoped semiconductor layer forming a superlattice structure of an electron supplying layer, the undoped semiconductor layer having a mixed crystal of aluminum gallium arsenide with an aluminum mixed ratio set to fall in the proximity of a critical mixed crystal ratio between direct transition and indirect transition.

Abstract: A sparse-carrier device includes a crystal structure with a crystallographic facet having contacts at opposite ends. Quantum dots are formed in first and second rows on the facet approximately one quantum dot wide and a plurality of quantum dots long, the quantum dots in the first row being separated from each other by a first distance smaller than a second distance between the quantum dots in the first row and adjacent quantum dots in a second row. The first distance is small enough to allow carrier tunneling between adjacent quantum dots and the second distance is large enough to substantially prevent tunneling between adjacent quantum dots and small enough to allow Coulombic interaction between adjacent quantum dots. Electrical contacts are formed at opposite ends of the rows to allow tunneling of carriers into and out of quantum dots in the first and second rows.

Abstract: A semiconductor device includes a superlattice having a first semiconductor layer having a first band-gap, a second semiconductor layer having a band-gap narrower than the first band-gap, the superlattice having a band structure with an energy level of a conduction band of the second semiconductor layer being lower than an energy level of a conduction band of the first semiconductor layer and an energy level of a valence band of the second semiconductor layer being lower than an energy level of a valence band of the first semiconductor layer, or a band structure with an energy level of a conduction band of the second semiconductor layer being higher than an energy level of a conduction band of the first semiconductor layer and an energy level of a valence band of the second semiconductor layer being lower than an energy level of a valence band of the first semiconductor layer, an exposed face formed on a plane different from a plane orientation on which the superlattice is formed, an end face of the superlatt

Abstract: There is provided a field effect transistor including a semi-insulating semiconductor substrate formed with a recess at a region in which a gate is to be formed, a gate base layer formed on the recess and composed of one of an InP layer and a plurality of layers including an InP layer, and a gate electrode formed on the gate base layer. The InP layer may be replaced with an InGaP layer, an AlXGa1−XAs (0≦X≦1) layer, an InXGa1−XAs (0≦X≦1) layer, or an InXAl1−XAs (0≦X<0.4 or 0.6<X≦1) layer. The above-mentioned field effect transistor prevents thermal instability thereof caused by impurities such as fluorine entering a donor layer to thereby inactivate donor. As a result, there is presented a highly reliable compound field effect transistor.

Abstract: A nitride-type III-V group compound semiconductor device includes a substrate and a layered structure including at least a channel layer using two-dimensional electron gas formed over a substrate, wherein the channel layer contains InN.

Abstract: A semiconductor device is constituted by a quantum-wave interference layer with plural periods of a pair of a first layer W and a second layer B. The second layer B has wider band gap than the first layer W. Each thickness of the first layer W and the second layer B is determined by multiplying by an odd number one fourth of wavelength of quantum-wave of carriers in each of the first layer W and the second layer B existing around the lowest energy level of the second layer B. A &dgr; layer, for sharply varying energy band, is formed at an every interface between the first layer W and the second layer B and has a thickness substantially thinner than the first layer W and the second layer B. The quantum-wave interference layer functions as a reflecting layer of carriers for higher reflectivity.

Abstract: A coating of liquid precursor containing a metal is applied to a first electrode, baked on a hot plate in oxygen ambient at a temperature not exceeding 300.degree. C. for five minutes, then RTP annealed at 675.degree. C. for 30 seconds. The coating is then annealed in oxygen or nitrogen ambient at 700.degree. C. for one hour to form a thin film of layered superlattice material with a thickness not exceeding 90 nm. A second electrode is applied to form a capacitor, and a post-anneal is performed in oxygen or nitrogen ambient at a temperature not exceeding 700.degree. C. If the material is strontium bismuth tantalate, the precursor contains u mole-equivalents of strontium, v mole-equivalents of bismuth, and w mole-equivalents of tantalum, where 0.8.ltoreq.u.ltoreq.1.0, 2.0.ltoreq.v.ltoreq.2.3, and 1.9.ltoreq.w.ltoreq.2.1.

Abstract: A semiconductor device includes a semi-insulating substrate. A channel layer is formed on the semi-insulating substrate. An electron supply layer is formed on the semi-insulating substrate for generating a two-dimensional electron gas. The electron supply layer includes a doped superlattice layer. The superlattice layer includes layers of In.sub.X Al.sub.1-X As and layers of In.sub.Y Al.sub.1-Y As which alternate with each other, where 0.ltoreq.X.ltoreq.1.0 and 0.ltoreq.Y.ltoreq.1.0, and X differs from Y.

Abstract: A quantum device functioning as a memory device is provided for allowing high-speed writing and erasing of data with a low gate voltage. A source electrode and a drain electrode are formed on a substrate. A gate electrode is formed between the source and drain electrodes. Between the substrate and the gate electrode, a first barrier layer, a first quantum well layer, a second barrier layer, a second quantum well layer and a third barrier layer are stacked to form coupled quantum well layer. The thickness of each of the first and second barrier layers allows electron tunneling. The thickness of the third barrier layer does not allow electron tunneling. The energy level of the first quantum well layer is higher than the Fermi level of a conduction layer. The energy level of the second quantum well layer is lower than the energy level of the first quantum well layer.

Abstract: The semiconductor device comprises a first insulating layer formed on the semiconductor substrate, at least one double-deck semiconductor nanocrystal formed on the first insulating layer, the at least one double-deck semiconductor nanocrystal comprising a first semiconductor nanocrystal and a second semiconductor nanocrystal stacked one upon the other via a second insulating layer, and a third insulating layer selectively formed on the first insulating layer so as to cover the at least one double-deck semiconductor nanocrystal.

Abstract: A controllable conduction device in the form of a transistor comprises source and drain regions 5, 2 between which extends a conduction path P for charge carriers, a gate 4 for controlling charge carrier flow along the conduction path and a multiple layer structure 3 providing a multiple tunnel junction configuration in the conduction path, with the result that current leakage is blocked by the multiple tunnel junction configuration when the transistor is in its off state. Vertical and lateral transistor configurations are described, together with use of the transistor in complimentary pairs and for a random access memory cell. Improved gate structures are described which are also applicable to memory devices that incorporate the tunnel barrier configuration to store charge on the memory node.

Abstract: The invention concerns heterostructure field effect transistors (HFET's) with high charge carrier concentration in the two-dimensional charge-carrier gas. The n-HFET of the heterostructure layer sequence contains several zones with formed 2DEG while the p-HFET contains several zones with formed 2DHG, which can be gate-controlled with a transistor gate, without mutually screening each other. At the same time, more charge carriers n.sub.s with high mobility are available through several channels. Higher transconductances for transistors are obtained with this, resulting in the promise of shorter switching times, especially for integrated circuits. In addition, other characteristics that are critical for the high-frequency technology, such as transit frequency and maximum operating frequency, can also be increased.

Abstract: In a semiconductor device, concave sections in which an opening area becomes small in proportion as a depth becomes deep are formed in a crystal layer, and a quantum structure is formed on at least one crystal face of a bottom section of the concave section and a border formed between plural sidewalls thereof. In case the quantum structure is formed in the bottom section, a quantum box is formed therein. If the quantum structure is formed in the border between the sidewalls of the concave section, a quantum wire is formed therein. In case the quantum structure is formed in the sidewall of the concave section, a two-dimensional quantum well is formed therein.

Abstract: A semiconductor nonvolatile memory device capable of lowering an operation voltage such as an erase voltage and capable of lowering costs and a method of production of the same, wherein a thin film transistor acting as the memory transistor is formed with a semiconductor layer 31b having a channel formation region formed on an insulating substrate 10 made of glass or plastic, a charge storing layer 32a formed on the semiconductor layer, a control gate 33a formed above the charge storing layer, and source and drain regions formed connected to the channel formation region.

Abstract: The present invention discloses a technique for applying diffraction characteristic of electrons to a two-dimensional electronic device to manufacture multi-functional transistor having various ON/OFF states. A quantum diffraction transistor according to the present invention is capable of adjusting the amplitude of drain current and having various ON/OFF states utilizing diffraction characteristic of electrons by interposing a reflection-type diffraction grating in an electron path. The inventive multi-functional quantum diffraction transistor uses a two dimensional electron gas in formed at a different species junction in a semiconductor heterostructure, and has a bent electron path between the source electrode and the drain electrode with a reflection-type diffraction grating. The quantum diffraction effect of the electrons is used for the control of the diffracted drain current.

Abstract: A hetero junction type field effect transistor can control a short channel effect, reduce the fluctuation of a threshold, and improve a yield. The hetero junction type field effect transistor comprises: a semiconductor substrate, a first electron feed layer made of a doped semiconductor having a wider band gap than the channel layer, a channel layer made of a non-doped semiconductor, a second electron feed layer comprising a laminate structure of a plurality of semiconductor layers having a wider band gap than the channel layer and having a thickness of 100 .ANG. or less, and a gate electrode, a source electrode, and a drain electrode.

Abstract: Heteroepitaxy of lattice-mismatched semiconductor materials such as GaAs (110) on silicon (102) is accomplished by formation of a defect annihilating grid (104) on the silicon (102) prior to the epitaxy of the GaAs (110).

Abstract: A field-effect transistor has a channel layer of InGaAs, and a pair of wide bandgap layers disposed one on each side of the channel layer, with respective heterojunctions formed with the channel layer. The channel layer has a thickness ranging from 50 to 150 angstroms, which is substantially the same as two-dimensional electron gas layers that are formed in the channel layer. The wide bandgap layers have the same composition, and the same concentration of an impurity.

Abstract: Laminated layers including semiconductor or metal thin layers and insulative thin layers are formed on a substrate and after the laminated layers are patterned, and the laminated layers are oxidized from their side to form an oxidized area. This way, a 0-dimensional quantum box or one-dimensional quantum line having fine tunnel junctions surrounded by the oxidized area and a 0-dimension quantum box or a one-dimensional quantum line made of semiconductor or metal area interposed between the oxidized area and the insulative thin layers are formed in the laminated layers.

Abstract: There is provided a semiconductor memory device including a memory cell array having a plurality of multiple logical value memory cells arranged in a matrix, each memory cell storing a plurality of charge conditions each representing a logical value, a word line for selecting a memory cell in a column direction, a bit line for selecting a memory cell in a row direction, and a reading circuit for reading data stored in a selected memory, wherein the reading circuit includes a semiconductor superlattice including at least two sub-band levels under a continuation band, the semiconductor superlattice receiving bit line signals transmitted from the bit line, and transmitting an output signal each time when the bit line signal passes over each of the sub-band levels, and a counter for counting the output signals to output read logical values.

Abstract: A channel layer and a spacer layer form a heterojunction therebetween. A V-shaped groove is formed in the spacer layer. The sharp bottom of the V-shaped is located above the heterojunction interface. On the bottom of the V-shaped groove a plurality of quantum dots are formed in a line and discretely. A gate electrode is formed above the quantum dots. A source electrode is connected to the heterojunction interface to form an ohmic contact therebetween. A drain electrode is connected to the heterojunction interface to form an ohmic contact therebetween. The quantum dots are arranged between the source and drain electrodes.

Abstract: This invention relates to the field of semiconductor devices. Silicon-based semiconductor devices ordinarily lack desirable optical properties because silicon's small, indirect band gap causes electrons to emit radiation with negligible quantum efficiency. This invention solves that problem by taking advantage of the change in the nature of the electron band gap when electron flow is confined within a one-dimensional channel known as a quantum wire. By biasing the junction between the quantum wire and the surrounding silicon support matrix with a voltage, a semiconductor device of this invention emits radiation of a variable and modulable wavelength, including visible light, as well as of a variable and modulable intensity. Alternatively, the workings of the device may be reversed such that it detects incoming radiation. Given its optical properties, such a device has numerous applications in the field of optoelectronics and integrated circuits.

Abstract: A structure of periodically varying density is provided, that acts as a phonon resonator for phonons capable of participating in phonon-electron interactions. Specifically, a phonon resonator that is resonant for phonons of appropriate momentum to participate in indirect radiative transitions and/or inter zone intervalley scattering events is provided. Preferably, the structure is an isotope superlattice, most preferably of silicon. The structure of the present invention has improved optical, electrical, and/or heat transfer properties. A method of preparing a the structure of the present invention is also provided.

Abstract: A mesoscopic structure is fabricated such that the desired dominant modes of the acoustic phonons in the structure have wavelengths such that the length of a half-integral number of wavelengths equals the length of the structure through which the desired electron wave is propagating. A manner of achieving this object is to provide for a material in a quantum wire and a material at the end of the quantum wire such that the two materials have such different properties (as disclosed hereinafter) to abruptly dampen the phonon modes at the interface between the two materials. With such an interface, a clamped boundary condition will occur and the modes of amplitude can be assumed to vanish at the interface. Such a case applies at some metal-semiconductor interfaces. In particular, for a mesoscopic device having wire-like regions which terminate on a variety of metal regions (regions used as contacts, gates, barriers, etc.), it is satisfactory to apply clamped boundary conditions.

Abstract: A field-effect transistor including a channel layer, a source electrode, a drain electrode, a high-resistance layer provided on the channel layer between the source electrode and the drain electrode and a gate electrode provided in an opening formed in the high-resistance layer, wherein the high-resistance layer is defined by a first side-wall facing the source electrode and a second side-wall facing the drain electrode, such that the first side-wall is separated from the source electrode.

Abstract: A low subthreshold leakage current, p-channel HFET including a GaAs supporting substrate with a first GaAs buffer layer and a first Al.sub.0.75 Ga.sub.0.25 As diffusion barrier layer formed thereon and a low temperature grown layer, including one of GaAs and AlGaAs, grown at 200.degree. C. on the first diffusion barrier layer. A second Al.sub.0.75 Ga.sub.0.25 As diffusion barrier layer is positioned on the low temperature grown layer and a second GaAs buffer layer is grown on the second diffusion barrier layer. A p-channel HFET is formed on the second buffer layer.

Abstract: A semiconductor quantum dot device using a semiconductor quantum dot comprises a semiconductor quantum dot formed on a semiconductor wafer, a field effect transistor formed on said semiconductor wafer and comprising a gate electrode formed in a vicinity of said semiconductor quantum dot, and a coupling means to couple said gate electrode and said semiconductor quantum dot capacitively.