Abstract: A method for making a semiconductor device may include forming a superlattice comprising a plurality of stacked groups of layers. Each group of layers of the superlattice may include a plurality of stacked base silicon monolayers defining a base silicon portion and an energy band-modifying layer thereon. The energy band-modifying layer may include at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base silicon portions. The method may further include forming a semiconductor layer adjacent the superlattice and comprising at least one first region therein including a first conductivity type dopant. At least one second region may be formed in the superlattice including a second conductivity type dopant to define, with the at least one first region, at least one semiconductor junction.

Abstract: A method for manufacturing gallium nitride based transparent conductive oxidized film ohmic electrodes includes forming a transparent conductive film on a GaN layer, forming a transparent conductive hetero-junction of opposing electrical characteristics on a transparent conductive film on the surface of the GaN layer through an ion diffusion process, and laying a metallic thick film on the surface of the transparent conductive hetero-junction for wiring process in the later fabrication operation. Thus through the electron and hole tunneling effect in the ion diffusion process the Fermi level of the hetero-junction may be improved to form an ohmic contact electrode.

Abstract: To provide a semiconductor device which makes it possible to avoid deterioration in the step coverage property at a gate electrode provided on an operating region and decrease a leakage current between the operating region and the gate electrode. The semiconductor device arranged as a HEMT is made to include an operating region composed of multilayer films, such as a channel layer, an electron supplying layer and other semiconductor layer, and having an island structure independently mesa-isolated from one another. The semiconductor device also includes a gate electrode and an impurity diffusion layer provided on the surface of the operating region, the impurity diffusion layer being doped with an impurity having a conductivity type inverse to the impurity doped into the electron supplying layer.

Abstract: To provide a semiconductor device which makes it possible to avoid deterioration in the step coverage property at a gate electrode provided on an operating region and decrease a leakage current between the operating region and the gate electrode. The semiconductor device arranged as a HEMT is made to include an operating region composed of multilayer films, such as a channel layer, an electron supplying layer and other semiconductor layer, and having an island structure independently mesa-isolated from one another. The semiconductor device also includes a gate electrode and an impurity diffusion layer provided on the surface of the operating region, the impurity diffusion layer being doped with an impurity having a conductivity type inverse to the impurity doped into the electron supplying layer.

Abstract: To provide a semiconductor device which makes it possible to avoid deterioration in the step coverage property at a gate electrode provided on an operating region and decrease a leakage current between the operating region and the gate electrode. The semiconductor device arranged as a HEMT is made to include an operating region composed of multilayer films, such as a channel layer, an electron supplying layer and other semiconductor layer, and having an island structure independently mesa-isolated from one another. The semiconductor device also includes a gate electrode and an impurity diffusion layer provided on the surface of the operating region, the impurity diffusion layer being doped with an impurity having a conductivity type inverse to the impurity doped into the electron supplying layer.

Abstract: A transistor and method of manufacturing thereof having stressed material layers formed in the channel to increase the speed and improve performance of the transistor. A layer of silicon and carbon is epitaxially grown in the channel region. A thin semiconductor material may be formed over the layer of silicon and carbon, and a stressed semiconductor layer may be epitaxially grown prior to forming the layer of silicon and carbon.

Abstract: The following layers are successively formed on a heavily-doped n-type first subcollector layer: a heavily-doped n-type second subcollector layer made of a material having a small band gap; an i-type or a lightly-doped n-type collector layer; a heavily-doped p-type base layer; an n-type emitter layer made of a material having a large band gap; a heavily-doped n-type emitter cap layer; and a heavily-doped n-type emitter contact layer made of a material having a small band gap. Alloying reaction layers are formed under an emitter electrode, a base electrode and a collector electrode.

Abstract: A method for producing a nitride semiconductor comprising growing at least first to third nitride semiconductor layers on a substrate; said first nitride semiconductor layer being grown at 400–600° C.; and said second and third nitride semiconductor layers being grown on said first nitride semiconductor layer at 700–1,300° C. after heat-treating said first nitride semiconductor layer at 700–1,300° C.; used as a carrier gas supplied near said substrate together with a starting material gas being a hydrogen/nitrogen mixture gas containing 63% or more by volume of hydrogen during growing said second nitride semiconductor layer, and a hydrogen/nitrogen mixture gas containing 50% or more by volume of nitrogen during growing said third nitride semiconductor layer; and said second nitride semiconductor layer being formed to a thickness of more than 1 ?m.

Abstract: An integrated circuit (IC) with high electron mobility transistors, such as enhancement mode pseudomorphic high electron mobility transistors (E-pHEMTs) and method for fabricating the IC utilizes an increased gate-to-drain etch recess spacing in some of the high electron mobility transistors to provide on-chip electrostatic discharge protection. The use of the increased gate-to-drain etch recess spacing allows smaller high electron mobility transistors to be used for ancillary low speed applications on the IC, which reduces the chip area occupied by these ancillary transistors.

Abstract: A structure for use as a MOSFET employs an SOI wafer with a SiGe island resting on the SOI layer and extending between two blocks that serve as source and drain; epitaxially grown Si on the vertical surfaces of the SiGe forms the transistor channel. The lattice structure of the SiGe is arranged such that the epitaxial Si has little or no strain in the direction between the S and D and a significant strain perpendicular to that direction.

Abstract: In a method for fabricating a semiconductor device, a first semiconductor layer of aluminum gallium nitride is first formed on a substrate, and a protection film containing silicon is then formed on the first semiconductor layer in such a manner that a device-isolation region is uncovered. Thereafter, the method further includes the step of heat-treating the first semiconductor layer in an oxidizing atmosphere whose temperature is adjusted to be within a range of 950° C. or more and 1050° C. or less.

Abstract: In a method of forming a semiconductor device with a first channel layer formed over a portion of a second channel layer, a portion of the second channel underlying the first channel is etched so as to form an overhanging ledge in the first channel, and then a metallic contact disposed on top of the ledge portion is diffused into the first channel by ohmic alloying to form an electrode in the first channel.

Abstract: A method for forming and the structure of a strained lateral channel of a field effect transistor, a field effect transistor and CMOS circuitry is described incorporating a drain, body and source region on a single crystal semiconductor substrate wherein a hetero-junction is formed between the source and body of the transistor, wherein the source region and channel are independently lattice strained with respect the body region. The invention reduces the problem of leakage current from the source region via the hetero-junction and lattice strain while independently permitting lattice strain in the channel region for increased mobility via choice of the semiconductor materials and alloy composition.

Abstract: A heterojunction bipolar transistor is provided that has a reduced turn-on voltage threshold. A base spacer layer is provided and alternately an emitter layer is provided that has a lowered energy gap. The lowered energy gap of the base spacer or the emitter spacer allow the heterojunction bipolar transistor to realize a lower turn-on voltage threshold. The thickness of the emitter layer if utilized is kept to a minimum to reduce the associated space charge recombination current in the heterojunction bipolar transistor.

Abstract: A high electron mobility transistor comprises a GaN-based electron accumulation layer formed on a substrate, an electron supply layer formed on the electron accumulation layer, a source electrode and a drain electrode formed on the electron supply layer and spaced from each other, a gate electrode formed on the electron supply layer between the source and drain electrodes, and a hole absorption electrode formed on the electron accumulation layer so as to be substantially spaced from the electron supply layer. Since the hole absorption electrode is formed on the electron absorption layer in order to prevent holes generated by impact ionization from being accumulated on the electron accumulation layer, a kink phenomenon is prevented. Good drain-current/voltage characteristics are therefore obtained. A high power/high electron mobility transistor is provided with a high power-added efficiency and good linearity.

Abstract: The present invention provides a unit cell of a metal-semiconductor field-effect transistor (MESFET). The unit cell of the MESFET includes a delta doped silicon carbide MESFET having a source, a drain and a gate. The gate is situated between the source and the drain and extends into a doped channel layer of a first conductivity type. Regions of silicon carbide adjacent to the source and the drain extend between the source and the gate and the drain and the gate, respectively. The regions of silicon carbide have carrier concentrations that are greater than a carrier concentration of the doped channel layer and are spaced apart from the gate.

Abstract: A semiconductor device includes a substrate, a first epitaxial layer, a second epitaxial layer, a third epitaxial layer, a first trench, and a second trench. The first epitaxial layer is formed on the substrate. The first layer has lattice mismatch relative to the substrate. The second epitaxial layer is formed on the first layer, and the second layer has lattice mismatch relative to the first layer. The third epitaxial layer is formed on the second layer, and the third layer has lattice mismatch relative to the second layer. Hence, the third layer may be strained silicon. The first trench extends through the first layer. The second trench extends through the third layer and at least partially through the second layer. At least part of the second trench is aligned with at lease part of the first trench, and the second trench is at least partially filled with an insulating material.

Abstract: Field-Effect Transistor Based on Embedded Cluster Structures and Process for Its Production In field-effect transistors, semiconductor clusters, which can extend from the source region to the drain region and which can be implemented in two ways, are embedded in one or a plurality of layers. In a first embodiment, the semiconductor material of the adjacent channel region can be strained by the clusters and the effective mass can thus be reduced by altering the energy band structure and the charge carrier mobility can be increased. In a second embodiment, the clusters themselves can be used as a canal region. These two embodiments can also appear in mixed forms. The invention can be applied to the Si material system with SiGe clusters or to the GaAs material system with InGaAs clusters or to other material systems.

Abstract: A microwave field effect transistor (10) has a high conductivity gate (44) overlying a double heterojunction structure (14, 18, 22) that has an undoped channel layer (18). The heterojunction structure overlies a substrate (12). A recess layer that is a not intentionally doped (NID) layer (24) overlies the heterojunction structure and is formed with a predetermined thickness that minimizes impact ionization effects at an interface of a drain contact of source/drain ohmic contacts (30) and permits significantly higher voltage operation than previous step gate transistors. Another recess layer (26) is used to define a gate dimension. A Schottky gate opening (42) is formed within a step gate opening (40) to create a step gate structure. A channel layer (18) material of InxGa1?xAs is used to provide a region of electron confinement with improved transport characteristics that result in higher frequency of operation, higher power density and improved power-added efficiency.

Abstract: There are disclosed techniques for providing a simplified process sequence for fabricating a semiconductor device. The sequence starts with forming an amorphous film containing silicon. Then, an insulating film having openings is formed on the amorphous film. A catalytic element is introduced through the openings to effect crystallization. Thereafter, a window is formed in the insulating film, and P ions are implanted. This process step forms two kinds of regions simultaneously (i.e., gettering regions for gettering the catalytic element and regions that will become the lower electrode of each auxiliary capacitor later).

Abstract: A hetero field effect transistor according to the present invention comprises an InP substrate, a channel layer provided on the InP substrate with a buffer layer disposed between the InP substrate and the channel layer, a spacer layer constituted by a semiconductor having a band gap larger than that of the channel layer formed to hetero-join to the channel layer, and a carrier supply layer formed to be adjacent to the spacer layer, wherein the channel layer comprises a predetermined semiconductor layer constituted by a compound semiconductor represented by a formula GaxIn1?xNyA1?y in which A is As or Sb, composition x satisfies 0?x?0.2, and composition y satisfies 0.03?y?0.10.

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: The invention is directed to compositions of mutated binding proteins containing reporter groups, analyte biosensor devices derived there from, and their use as analyte biosensor both in vitro and in vivo.

Abstract: A multi-layer film 10 is formed by stacking a Si1-x1-y1Gex1Cy1 layer (0?x1<1 and 0<y1<1) having a small Ge mole fraction, e.g., a Si0.785Ge0.2C0.015 layer 13, and a Si1-x2-y2Gex2Cy2 layer (0<x2?1 and 0?y2<1) (where x1<x2 and y1>y2) having a high Ge mole fraction, e.g., a Si0.2Ge0.8 layer 12. In this manner, the range in which the multi-layer film serves as a SiGeC layer with C atoms incorporated into lattice sites extends to high degrees in which a Ge mole fraction is high.

Abstract: A MOSFET device including a semiconductor substrate, an SiGe layer provided on top of the semiconductor substrate, an Si layer provided on top of the SiGe layer; and a first isolation region for separating the Si layer into a first region and a second region, wherein the Si layer in the second region is turned into an Si epitaxial layer greater in thickness than the Si layer in the first region. The MOSFET device further includes at least one first MOSFET with the Si layer in the first region serving as a strained Si channel, and at least one second MOSFET with the Si epitaxial layer serving as an Si channel.

Abstract: In a field effect transistor, an Si layer, an SiC (Si1-yCy) channel layer, a CN gate insulating film made of a carbon nitride layer (CN) and a gate electrode are deposited in this order on an Si substrate. The thickness of the SiC channel layer is set to a value that is less than or equal to the critical thickness so that a dislocation due to a strain does not occur according to the carbon content. A source region and a drain region are formed on opposite sides of the SiC channel layer, and a source electrode and a drain electrode are provided on the source region and the drain region, respectively.

Abstract: A method is provided for forming a self-aligned, selectively etched, double recess high electron mobility transistor. The method includes providing a semiconductor structure having a III-V substrate; a first relatively wide band gap layer, a channel layer, a second relatively wide band gap Schottky layer, an etch stop layer; a III-V third wide band gap layer on etch stop layer; and an ohmic contact layer on the third relatively wide band gap layer. A mask is provided having a gate contact aperture to expose a gate region of the ohmic contact layer. A first wet chemical etch is brought into contact with portions of the ohmic contact layer exposed by the gate contact aperture. The first wet chemical selectively removes exposed portions of the ohmic contact layer and underlying portions of the third relatively wide band gap layer. The etch stop layer inhibits the first wet chemical etch from removing portions of such etch stop layer.

Abstract: A method of manufacturing a semiconductor component includes providing a substrate (110) with a surface (119), providing a layer (120) of undoped gallium arsenide over the surface of the substrate, forming a gate contact (210) over a first portion of the layer, and removing a second portion of the layer.

Abstract: Resist patterns (R11 and R12) are formed such that an opening between both the films is aligned to the position, where the source electrode (7) is formed, while the region on the N+-layer (5), where the drain electrode (8) is formed afterwards, is covered by the resist film (R11). After ohmic electrode material is applied from a direction perpendicular to a semiconductor substrate (1), the resist films (R11 and R12) are removed with the ohmic electrode films (OM11 and OM12). The remaining ohmic electrode film (OM14) functions as the source electrode (7). After the above-described first lift off process, the second lift off process is performed to form a drain electrode (8) on the N+-layer (5).

Abstract: A transistor structure is provided. This structure has a source electrode and a drain electrode. A doped cap layer of GaxIn1−xAs is disposed below the source electrode and the drain electrode and provides a cap layer opening. An undoped resistive layer of GaxIn1−xAs is disposed below the cap layer and defines a resistive layer opening in registration with the cap layer opening and having a first width. A Schottky layer of AlyIn1−yAs is disposed below the resistive layer. An undoped channel layer is disposed below the Schottky layer. A semi-insulating substrate is disposed below the channel layer. A top surface of the Schottky layer beneath the resistive layer opening provides a recess having a second width smaller than the first width. A gate electrode is in contact with a bottom surface of the recess provided by the Schottky layer.

Abstract: A semiconductor device includes an AlGaN film formed on a GaN film on a substrate, a gate electrode formed on the AlGaN film, and source and drain electrodes formed on either side of the gate electrode on the AlGaN film. An n-type InxGayAl1-x-yN film is interposed between the source and drain electrodes and the AlGaN film. Alternatively, the semiconductor device includes an n-type InxGayAl1-x-yN film formed on a GaN film on a substrate, a gate electrode formed on the InxGayAl1-x-yN film, and source and drain electrodes formed on either side of the gate electrode on the InxGayAl1-x-yN film.

Abstract: High electron mobility transistors (HEMTs) and methods of fabricating HEMTs are provided Devices according to embodiments of the present invention include a gallium nitride (GaN) channel layer and an aluminum gallium nitride (AlGaN) barrier layer on the channel layer. A first ohmic contact is provided on the barrier layer-to provide a source electrode and a second ohmic contact is also provided on the barrier layer and is spaced apart from the source electrode to provide a drain electrode. A GaN-based cap segment is provided on the barrier layer between the source electrode and the drain electrode. The GaN-based cap segment has a first sidewall adjacent and spaced apart from the source electrode and may have a second sidewall adjacent and spaced apart from the drain electrode. A non-ohmic contact is provided on the GaN-based cap segment to provide a gate contact. The gate contact has a first sidewall which is substantially aligned with the first sidewall of the GaN-based cap segment.

Abstract: A method of producing nitride based heterostructure devices by using a quaternary layer comprised of AlInGaN. The quaternary layer may be used in conjunction with a ternary layer in varying thicknesses and compositions that independently adjust polarization charges and band offsets for device structure optimization by using strain compensation profiles. The profiles can be adjusted by altering profiles of molar fractions of In and Al.

Abstract: A method for fabricating semiconductor devices with thin (e.g., submicron) and/or thick (e.g., between 1 micron and 100 microns thick) Group III nitride layers during a single epitaxial run is provided, the layers exhibiting sharp layer-to-layer interfaces. According to one aspect, an HVPE reactor is provided that includes one or more gas inlet tubes adjacent to the growth zone, thus allowing fine control of the delivery of reactive gases to the substrate surface. According to another aspect, an HVPE reactor is provided that includes at least one growth zone as well as a growth interruption zone. According to another aspect, an HVPE reactor is provided that includes extended growth sources such as slow growth rate gallium source with a reduced gallium surface area. According to another aspect, an HVPE reactor is provided that includes multiple sources of the same material, for example Mg, which can be used sequentially to prolong a growth cycle.

Abstract: A method for manufacturing a hetero-junction field effect transistor (HFET) device, which includes sequentially forming a non-doped GaN semiconductor layer and an AlGaN semiconductor layer on a substrate, separating devices from each other by etching the substrate, forming a photoresist layer pattern on the AlGaN semiconductor layer and forming gate electrodes by depositing a material on the substrate using the photoresist layer pattern, treating the surface of the AlGaN semiconductor layer, and forming a photoresist layer pattern on the substrate and forming ohmic electrodes by depositing a metal on the substrate using the photoresist layer pattern, is provided. Accordingly, it is possible to overcome a difficulty in aligning the gate electrode with the ohmic electrodes and prevent a substrate from having a step difference introduced by the ohmic electrodes because the gate electrode is formed before the ohmic electrodes are formed.

Abstract: There is provided an electronic device. The electronic device includes at least one epitaxial semiconductor layer disposed on a single crystal substrate comprised of gallium nitride having a dislocation density less than about 105 per cm2. A method of forming an electronic device is also provided. The method includes providing a single crystal substrate comprised of gallium nitride having a dislocation density less than about 105 per cm2, and homoepitaxially forming at least one semiconductor layer on the substrate.

Abstract: A gate electrode of an n-channel IGFET includes a first region composed of at least a first IV group element and a second IV group element which are different from each other, and a second region composed of the first IV group element. Similarly, a gate electrode of a p-channel IGFET includes first and second regions. For example, the first region is made of SiGe while the second region is made of Si. In both of the n-channel and P-channel IGFET, silicide electrodes are formed on the gate electrodes 4N and 4P through silicidation of at least parts of the second regions.

Abstract: The present invention provides a method for manufacturing a semiconductor substrate, comprising the step of: forming a first buffer Si layer on a substrate having a silicon surface; epitaxially growing, in sequence, a first strained SiGe layer and a first Si layer above the first buffer Si layer; implanting ions into the resulting substrate followed by annealing so as to relax the lattice of the first strained SiGe layer and to thereby providing tensile strain in the first Si layer and so that tensile strain is provided in the first Si layer; and epitaxially growing, in sequence, a second buffer Si layer and a second SiGe layer above the rezulting substrate; and forming a second Si layer having tensile strain on the second SiGe layer.

Abstract: A method of producing a strain-relaxed Si—Ge virtual substrate for use in a semiconductor substrate which is planar and of less defects for improving the performance of a field effect semiconductor device, which method comprises covering an Si—Ge layer formed on an SOI substrate with an insulating layer to prevent evaporation of Ge, heating the mixed layer of silicon and germanium at a temperature higher than a solidus curve temperature determined by the germanium content of the Si—Ge layer into a partially melting state, and diffusing germanium to the Si layer on the insulating layer, thereby solidifying the molten Si—Ge layer to obtain a strain-relaxed Si—Ge virtual substrate.

Abstract: A method for fabricating a semiconductor device which protects the ohmic metal contacts and the channel of the device during subsequent high temperature processing steps is explained. An encapsulation layer is used to cover the channel and ohmic metal contacts. The present invention provides a substrate on which a plurality of semiconductor layers are deposited. The semiconductor layers act as the channel of the device. The semiconductor layers are covered with an encapsulation layer. A portion of the encapsulation layer and the plurality of semiconductor layers are removed, wherein ohmic metal contacts are deposited. The ohmic metal contacts are then annealed to help reduce their resistance. The encapsulation layer ensures that the ohmic metal contacts do not migrate during the annealing step and that the channel is not harmed by the high temperatures needed during the annealing step.

Abstract: A method of manufacturing a high electron mobility transistor, comprising laminating an electron accumulation layer and an electron supply layer successively on a substrate; selectively removing the electron supply layer to isolate an element region; forming a source and a drain electrode on the electron supply layer of the isolated element region; and forming a hole absorption electrode on the electron accumulation layer exposed by the selective removal of the electron supply layer, and simultaneously forming a gate electrode on the electron supply layer of the isolated element region.

Abstract: Structures and methods for fabricating high speed digital, analog, and combined digital/analog systems using planarized relaxed SiGe as the materials platform. The relaxed SiGe allows for a plethora of strained Si layers that possess enhanced electronic properties. By allowing the MOSFET channel to be either at the surface or buried, one can create high-speed digital and/or analog circuits. The planarization before the device epitaxial layers are deposited ensures a flat surface for state-of-the-art lithography. In accordance with one embodiment of the invention, there is provided a method of fabricating a semiconductor structure including providing a relaxed Si1−xGex layer on a substrate; planarizing said relaxed Si1−xGex layer; and depositing a device heterostructure on said planarized relaxed Si1−xGex layer including at least one strained layer.

Abstract: A process and related product in which ohmic contacts are formed in High Electron Mobility Transistors (HEMTs) employing compound substrates such as gallium nitride. An improved device and an improvement to a process for fabrication of ohmic contacts to GaN/AlGaN HEMTs using a novel two step resist process to fabricate the ohmic contacts are described. This novel two-step process consists of depositing a plurality of layers having compounds of Group III V elements on a substrate; patterning and depositing a first photoresist on one of the layers; etching recessed areas into this layer; depositing ohmic metals on the recessed areas; removing the first photoresist; patterning and depositing a second photoresist, smaller in profile than the first photoresist, on the layer; depositing more ohmic metal on the layer allowing for complete coverage of the recessed areas; removing the second photoresist, and annealing the semiconductor structure.

Abstract: Methods for fabricating multi-layer semiconductor structures including strained material layers using a minimum number of process tools and under conditions optimized for each layer. Certain regions of the strained material layers are kept free of impurities that can interdiffuse from adjacent portions of the semiconductor. When impurities are present in certain regions of the strained material layers, there is degradation in device performance. By employing semiconductor structures and devices (e.g., field effect transistors or “FETs”) that have the features described, or are fabricated in accordance with the steps described, device operation is enhanced.

Abstract: A semiconductor device having a transistor of gate all around (GAA) type and a method of fabricating the same are disclosed. A SOI substrate composed of a SOI layer, a buried oxide layer and a lower substrate is prepared. The SOI layer has at least one unit dual layer of a silicon germanium layer and a silicon layer. The SOI layer is patterned to form an active layer pattern to a certain direction. An insulation layer is formed to cover the active layer pattern. An etch stop layer is stacked on the active layer pattern covered with the insulation layer. The etch stop layer is patterned and removed at a gate region crossing the active layer pattern at the channel region. The insulation layer is removed at the gate region. The silicon germanium layer is isotropically etched and selectively removed to form a cavity at the channel region of the active layer pattern.

Abstract: A transistor structure is provided. This structure has a source electrode and a drain electrode. A doped cap layer of GaxIn1−xAs is disposed below the source electrode and the drain electrode and provides a cap layer opening. An undoped resistive layer of GaxIn1−xAs is disposed below the cap layer and defines a resistive layer opening in registration with the cap layer opening and having a first width. A Schottky layer of AlyIn1−yAs is disposed below the resistive layer. An undoped channel layer is disposed below the Schottky layer. A semi-insulating substrate is disposed below the channel layer. A top surface of the Schottky layer beneath the resistive layer opening provides a recess having a second width smaller than the first width. A gate electrode is in contact with a bottom surface of the recess provided by the Schottky layer.

Abstract: A high electron mobility transistor comprises a GaN-based electron accumulation layer formed on a substrate, an electron supply layer formed on the electron accumulation layer, a source electrode and a drain electrode formed on the electron supply layer and spaced from each other, a gate electrode formed on the electron supply layer between the source and drain electrodes, and a hole absorption electrode formed on the electron accumulation layer so as to be substantially spaced from the electron supply layer. Since the hole absorption electrode is formed on the electron absorption layer in order to prevent holes generated by impact ionization from being accumulated on the electron accumulation layer, a kink phenomenon is prevented. Good drain-current/voltage characteristics are therefore obtained. A high power/high electron mobility transistor is provided with a high power-added efficiency and good linearity.

Abstract: The invention includes providing gallium nitride material devices having backside vias and methods to form the devices. The devices include a gallium nitride material formed over a substrate, such as silicon. The device also may include one or more non-conducting layers between the substrate and the gallium nitride material which can aid in the deposition of the gallium nitride material. A via is provided which extends from the backside of the device through the non-conducting layer(s) to enable electrical conduction between an electrical contact deposited within the via and, for example, an electrical contact on the topside of the device. Thus, devices of the invention may be vertically conducting. Exemplary devices include laser diodes (LDs), light emitting diodes (LEDs), power rectifier diodes, FETs (e.g., HFETs), Gunn-effect diodes, and varactor diodes, among others.

Abstract: To provide a semiconductor device which makes it possible to avoid deterioration in step coverage property at a gate electrode provided on an operating region, and decrease a leakage current between the operating region and the gate electrode. The semiconductor device arranged as a HEMT is made to include operating region composed of multilayer films such as a channel layer, an electron supplying layer and other semiconductor layer and having an island structure independently mesa-isolated from one another. The semiconductor device also includes a gate electrode and an impurity diffusion layer provided on the surface of the operating region, the impurity diffusion layer being doped with an impurity having a conductivity type inverse to the impurity doped into the electron supplying layer.

Abstract: A field-effect semiconductor device includes a channel layer; a barrier structure formed on the channel layer and including a plurality of semiconductor layers; a plurality of ohmic electrodes formed above the barrier structure; and a Schottky electrode formed on the barrier structure between the ohmic electrodes. The barrier structure has an electron-affinity less than that of the channel layer and includes at least two heavily doped layers and a lightly doped layer provided therebetween.