Abstract: A method of producing semiconductor materials and devices that incorporate the semiconductor materials are provided. In particular, a method is provided of producing a semiconductor material, such as a III-V semiconductor, on a silicon substrate using a compliant buffer layer, and devices such as photovoltaic cells that incorporate the semiconductor materials. The compliant buffer material and semiconductor materials may be deposited using coincident site lattice-matching epitaxy, resulting in a close degree of lattice matching between the substrate material and deposited material for a wide variety of material compositions. The coincident site lattice matching epitaxial process, as well as the use of a ductile buffer material, reduce the internal stresses and associated crystal defects within the deposited semiconductor materials fabricated using the disclosed method.

Abstract: A multilayer substrate structure comprises a substrate, a thermal matching layer formed on the substrate and a lattice matching layer above the thermal matching layer. The thermal matching layer includes at least one of molybdenum, molybdenum-copper, mullite, sapphire, graphite, aluminum-oxynitrides, silicon, silicon carbide, zinc oxides, and rare earth oxides. The lattice matching layer includes a first chemical element and a second chemical element to form an alloy. The first and second chemical element has similar crystal structures and chemical properties. The coefficient of thermal expansion of the thermal matching layer and the lattice parameter of the lattice matching layer are both approximately equal to that of a member of group III-V compound semiconductors. The lattice constant of the lattice matching layer is approximately equal to that of a member of group III-V compound semiconductor.

Abstract: A semiconductor structure comprises a substrate, a gate stack, a base area, and a source/drain region, wherein the gate stack is located on the base area, the source/drain region is located in the base area, and the base area is located on the substrate. A supporting isolated structure is provided between the base area and the substrate, wherein part of the supporting structure is connected to the substrate; a cavity is provided between the base area and the substrate, wherein the cavity is composed of the base area, the substrate and the supporting isolated structure. A stressed material layer is provided on both sides of the gate stack, the base area and the supporting isolated structure. Correspondingly, a method is provided for manufacturing such a semiconductor structure, which inhibits the short channel effect, reduces the parasitic capacitance and leakage current, and enhances the steepness of the source/drain region.

Abstract: Provided are a nitride-based semiconductor element with reduced leak current, and a manufacturing method thereof. The semiconductor element comprises a substrate; a buffer region that is formed above the substrate; an active layer that is formed on the buffer region; and at least two electrodes that are formed on the active layer. The buffer region includes a plurality of semiconductor layers having different lattice constants, and there is a substantially constant electrostatic capacitance between a bottom surface of the substrate and a top surface of the buffer region when a potential that is less than a potential of the bottom surface of the substrate is applied to the top surface of the buffer region and a voltage between the bottom surface of the substrate and the top surface of the buffer region is changed within a range corresponding to thickness of the buffer region.

Abstract: A first group III nitride semiconductor layer has a low carbon concentration region having a carbon concentration of less than 1×1017 cm?3, and located in a region under an edge of a gate electrode closer to a drain electrode, a thickness d2 of the low carbon concentration region satisfies Vm/(110·d1)?d2<Vm/(110·d1)+0.5 where d1 is a thickness of a nitride semiconductor layer including the first group III nitride semiconductor layer and the second group III nitride semiconductor layer, and Vm is an operating breakdown voltage, and a ratio of Ron to Ron0, which is an index of a current collapse value, satisfies Ron/Ron0?3 where Ron0 is an on-state resistance in a relaxed state, and Ron is an on-state resistance measured 100 ?s after a transition from an off state to an on state under an operating voltage Vm.

Abstract: Fin-defining mask structures are formed over a semiconductor material layer having a first semiconductor material and a disposable gate structure is formed thereupon. A gate spacer is formed around the disposable gate structure and physically exposed portions of the fin-defining mask structures are subsequently removed. The semiconductor material layer is recessed employing the disposable gate structure and the gate spacer as an etch mask to form recessed semiconductor material portions. Embedded planar source/drain stressors are formed on the recessed semiconductor material portions by selective deposition of a second semiconductor material having a different lattice constant than the first semiconductor material. After formation of a planarization dielectric layer, the disposable gate structure is removed. A plurality of semiconductor fins are formed employing the fin-defining mask structures as an etch mask. A replacement gate structure is formed on the plurality of semiconductor fins.

Abstract: A semiconductor device and a method for forming the same are provided. The semiconductor device comprises: a substrate (1); an insulating layer (2), formed on the substrate (1) and having a trench (21) to expose an upper surface of the substrate (1); a first buffer layer (3), formed on the substrate (1) and in the trench (21); and a compound semiconductor layer (4), formed on the first buffer layer (3), wherein an aspect ratio of the trench (21) is larger than 1 and smaller than 10, wherein the first buffer layer (3) is formed by a low-temperature reduced pressure chemical vapor deposition process at a temperature between 200° C. and 500° C., and wherein the compound semiconductor layer (4) is formed by a low-temperature metal organic chemical vapor deposition process at a temperature between 200° C. and 600° C.

Abstract: An n-type aluminum gallium nitride (AlGaN) thin film and an ultraviolet light emitting device including the same. The ultraviolet light emitting device includes: an aluminum nitride (AlN) buffer layer on a substrate; and an n-type AlGaN layer, an active layer, a p-type AlGaN layer that are sequentially stacked on the AlN buffer layer. A silicon doping density of the n-type AlGaN layer increases with respect to an increasing vertical position of the n-AlGaN layer with reference to the AlN buffer layer.

Abstract: A semiconductor device and method for fabricating a semiconductor device is disclosed. An exemplary semiconductor device includes a substrate including a first region and a second region. The semiconductor device further includes a first buffer layer formed over the substrate and between first and second isolation regions in the first region and a second buffer layer formed over the substrate and between first and second isolation regions in the second region. The semiconductor device further includes a first fin structure formed over the first buffer layer and between the first and second isolation regions in the first region and a second fin structure formed over the second buffer layer and between the first and second isolation regions in the second region. The first buffer layer includes a top surface different from a top surface of the second buffer layer.

Abstract: Provided is a semiconductor device that has a buffer layer with which a dislocation density is decreased. The semiconductor device includes a substrate, a buffer region formed over the substrate, an active layer formed on the buffer region, and at least two electrodes formed on the active layer. The buffer region includes at least one composite layer in which a first semiconductor layer having a first lattice constant, a second semiconductor layer having a second lattice constant that is different from the first lattice constant and formed in contact with the first semiconductor layer, and a third semiconductor layer having a third lattice constant that is between the first lattice constant and the second lattice constant are sequentially laminated.

Abstract: Provided is a semiconductor device that includes a substrate, a first buffer region formed over the substrate, a second buffer region formed on the first buffer region, an active layer formed on the second buffer region, and at least two electrodes formed on the active layer. The first buffer region includes at least one composite layer in which a first semiconductor layer and a second semiconductor layer are sequentially stacked. The second buffer region in includes at least one composite layer in which a third semiconductor layer, a fourth semiconductor layer, and a fifth semiconductor layer are sequentially stacked. The fourth lattice constant has a value between the third lattice constant and the fifth lattice constant.

Abstract: A semiconductor device includes a buffer layer formed with a semiconductor adapted to produce piezoelectric polarization, and a channel layer stacked on the buffer layer, wherein a two-dimensional hole gas, generated in the channel layer by piezoelectric polarization of the buffer layer, is used as a carrier of the channel layer. On a complementary semiconductor device, the semiconductor device described above and an n-type field effect transistor are formed on the same compound semiconductor substrate. Also, a level shift circuit is manufactured by using the semiconductor device. Further, a semiconductor device manufacturing method includes forming a compound semiconductor base portion, forming a buffer layer on the base portion, forming a channel layer on the buffer layer, forming a gate on the channel layer, and forming a drain and source with the gate therebetween on the channel layer.

Abstract: For an HEMT component, in particular on the basis of GaN, it is proposed, for the purpose of reducing field spikes in the conduction channel, in a partial section of the conduction channel between gate electrode and drain electrode, to set the sheet resistance of the conduction channel such that it is higher than in adjacent regions. Various measures for subsequently increasing the sheet resistance in an area-selective manner are specified.

Abstract: A semiconductor element having a high breakdown voltage includes a substrate, a buffer layer, a semiconductor composite layer and a bias electrode. The buffer layer disposed on the substrate includes a high edge dislocation defect density area. The semiconductor composite layer disposed on the buffer layer includes a second high edge dislocation defect density area formed due to the first high edge dislocation defect density area. The bias electrode is disposed on the semiconductor composite layer. A virtual gate effect of defect energy level capturing electrons is generated due to the first and second high edge dislocation defect density areas, such that an extended depletion region expanded from the bias electrode is formed at the semiconductor composite layer. When the bias electrode receives a reverse bias, the extended depletion region reduces a leakage current and increases the breakdown voltage of the semiconductor element.

Abstract: A method of forming a plurality of discrete, interconnected solar cells mounted on a carrier by providing a first semiconductor substrate; depositing on the first substrate a sequence of layers of semiconductor material forming a solar cell structure; forming a metal back contact layer over the solar cell structure; mounting a carrier on top of the metal back contact; removing the first substrate; and lithographically patterning and etching the solar cell structure to form a plurality of discrete solar cells mounted on the carrier.

Abstract: This invention relates to a semiconductor device and a manufacturing method therefor for reducing stacking faults caused by high content of Ge in an embedded SiGe structure. The semiconductor device comprises a Si substrate with a recess formed therein. A SiGe seed layer is formed on sidewalls of the recess, and a first SiGe layer having a Ge content gradually increased from bottom to top is formed on the recess bottom. A second SiGe layer having a constant content of Ge is formed on the first SiGe layer. The thickness of the first SiGe layer is less than the depth of the recess. The Ge content in the SiGe seed layer is less than the Ge content in the second SiGe layer, and the Ge content at the upper surface of the first SiGe layer is less than or equal to the Ge content in the second SiGe layer.

Abstract: Epitaxial formation structures and associated methods of manufacturing solid state lighting (“SSL”) devices with target thermal expansion characteristics are disclosed herein. In one embodiment, an SSL device includes a composite structure having a composite CTE temperature dependency, a formation structure on the composite structure, and an SSL structure on the formation structure. The SSL structure has an SSL temperature dependency, and a difference between the composite CTE and SSL temperature dependencies is below 3 ppm/° C. over the temperature range.

Abstract: Methods of fabricating a semiconductor layer or device and said devices are disclosed. The methods include but are not limited to providing a metal or metal alloy substrate having a crystalline surface with a known lattice parameter (a). The methods further include growing a crystalline semiconductor alloy layer on the crystalline substrate surface by coincident site lattice matched epitaxy. The semiconductor layer may be grown without any buffer layer between the alloy and the crystalline surface of the substrate. The semiconductor alloy may be prepared to have a lattice parameter (a?) that is related to the lattice parameter (a). The semiconductor alloy may further be prepared to have a selected band gap.

Abstract: An epitaxial structure includes a substrate having an epitaxial growth surface, a first epitaxial layer, a graphene layer and a second epitaxial layer. The first epitaxial layer is stacked on the epitaxial growth surface. The graphene layer is coated on the first epitaxial layer. The second epitaxial layer is located on the first epitaxial layer and covers the graphene layer.

Abstract: Fabrication of monolithic lattice-mismatched semiconductor heterostructures with limited area regions having upper portions substantially exhausted of threading dislocations, as well as fabrication of semiconductor devices based on such lattice-mismatched heterostructures.

Abstract: The present invention provides a transistor and a method for forming the same. The method includes: providing a semiconductor substrate having a semiconductor layer formed thereon, the semiconductor layer and the semiconductor substrate having different crystal orientations; forming a dummy gate structure on the semiconductor layer; forming a source region and a drain region in the semiconductor substrate and the semiconductor layer and at opposite sides of the dummy gate structure; forming an interlayer dielectric layer on the semiconductor layer, which is substantially flush with the dummy gate structure; removing the dummy gate structure and the semiconductor layer beneath the dummy gate structure, forming an opening in the interlayer dielectric layer and the semiconductor layer, the semiconductor substrate being exposed at a bottom of the opening; forming a metal gate structure in the opening. Saturation current of the transistor is raised, and performance of a semiconductor device is promoted.

Abstract: A semiconductor wafer includes a multilayered film having a structure in which nondoped first nitride semiconductor layers and nondoped second nitride semiconductor layers with a larger lattice constant than the first nitride semiconductor layer are laminated alternately, and a nondoped third nitride semiconductor layer which is located on the multilayered film and has a larger lattice constant than the first nitride semiconductor layer, wherein the semiconductor wafer has conductivity in a film-thickness direction.

Abstract: An As(arsenic)/Sb(antimony) compound semiconductor is grown on a Si(silicon) or Ge (germanium) substrate. With the present invention, island-like growth on the Si or Ge substrate owing to lattice constant mismatch is prevented. Bad electrical isolation owing to diffusion of Ge is also prohibited. The present invention could obtain a high quality metamorphic buffer which is suitable for integrating a Si or Ge substrate with an electronic or optoelectronic device of a III/V group semiconductor.

Abstract: Transistor structures having channel regions comprising alternating layers of compressively and tensilely strained epitaxial materials are provided. The alternating epitaxial layers can form channel regions in single and multigate transistor structures. In alternate embodiments, one of the two alternating layers is selectively etched away to form nanoribbons or nanowires of the remaining material. The resulting strained nanoribbons or nanowires form the channel regions of transistor structures. Also provided are computing devices comprising transistors comprising channel regions comprised of alternating compressively and tensilely strained epitaxial layers and computing devices comprising transistors comprising channel regions comprised of strained nanoribbons or nanowires.

Abstract: The invention relates to a process for fabricating a heterostructure. This process is noteworthy in that it comprises the following steps: a) a strained crystalline thin film is deposited on, or transferred onto, an intermediate substrate; b) a strain relaxation layer, made of crystalline material capable of being plastically deformed by a heat treatment at a relaxation temperature at which the material constituting the thin film deforms by elastic deformation is deposited on the thin film; c) the thin film and the relaxation layer are transferred onto a substrate; and d) a thermal budget is applied at at least the relaxation temperature, so as to cause the plastic deformation of the relaxation layer and the at least partial relaxation of the thin film by elastic deformation, and thus to obtain the final heterostructure.

Abstract: Device having reduced buffer leak on GaN substrate. In HEMT device, n-GaN (n-type GaN wafer) is used as substrate 11. Non-doped AlpGa1-pN layer with non-uniform composition p is formed on substrate 11 as buffer layer 12. On buffer layer 12, channel layer 13 of semi-insulating GaN and electron supply layer 14 of n-AlGaN are sequentially formed. In buffer layer 12, substrate connection region 121 where p=0 (GaN) is formed on lower end side, and active layer connection region 122 where value of p is also 0 (GaN) is formed on upper end side (channel layer 13 side). High Al composition region 123 where value of p is set to 1 (p=1) (AlN) is formed between substrate connection region 121 and active layer connection region 122. Resistivity of the high Al composition region 123 is highest in the buffer layer.

Abstract: A structure for an integrated circuit is disclosed. The structure includes a crystalline substrate and four crystalline layers. The first crystalline layer of first lattice constant is positioned on the crystalline substrate. The second crystalline layer has a second lattice constant different from the first lattice constant, and is positioned on said first crystalline layer. The third crystalline layer has a third lattice constant different than said second lattice constant, and is positioned on said second crystalline layer. The strained fourth crystalline layer includes, at least partially, a MOSFET device.

Abstract: A device and a method of making said wherein the device wherein the device has a group III-nitride buffer deposited on a substrate; and a group III-nitride heterostructure disposed on a surface of the group III-nitride buffer, wherein the group III-nitride heterostructure has a group III-nitride channel and a group III-nitride barrier layer disposed on a surface of the group III-nitride channel, the group III-nitride barrier layer including Al as one of its constituent group III elements, the Al having a mole fraction which varies at least throughout a portion of said group III-nitride barrier layer.

Abstract: A semiconductor device according to the present invention including: a substrate; a compound semiconductor layer formed on the substrate; an element forming area provided in the compound semiconductor layer; and at least one semiconductor element, which includes a first main electrode and a main second electrode, wherein the at least one semiconductor element is formed in the element forming area, wherein the compound semiconductor layer includes: a first compound growth layer, which is formed on the substrate and includes the element forming area; and a second compound growth layer formed on the substrate to surround the element forming area when viewed from a plane, wherein the second compound growth layer has a crystallinity lower than a crystallinity of the first compound growth layer.

Abstract: A method and a device made according to the method. The method comprises providing a substrate including a first material, and providing a fin including a second material, the fin being disposed on the substrate and having a device active portion, the first material and the second material presenting a lattice mismatch between respective crystalline structures thereof. Providing the fin includes providing a biaxially strained film including the second material on the substrate; and removing parts of the biaxially strained film to form a substantially uniaxially strained fin therefrom.

Abstract: A strain-induced layer is formed atop a MOS device in order to increase carrier mobility in the channel region. The dimension of the strain-induced layer in preferred embodiments may lead to an optimized drive current increase and improved drive current uniformity in an NMOS and PMOS device. An advantage of the preferred embodiments is that improved device performance is obtained without adding complex processing steps. A further advantage of the preferred embodiments is that the added processing steps can be readily integrated into a known CMOS process flow. Moreover, the creation of the photo masks defining the tensile and compressive strain-induced layers does not require extra design work on an existed design database.

Abstract: A method of producing semiconductor materials and devices that incorporate the semiconductor materials are provided. In particular, a method is provided of producing a semiconductor material, such as a III-V semiconductor, on a spinel substrate using a sacrificial buffer layer, and devices such as photovoltaic cells that incorporate the semiconductor materials. The sacrificial buffer material and semiconductor materials may be deposited using lattice-matching epitaxy or coincident site lattice-matching epitaxy, resulting in a close degree of lattice matching between the substrate material and deposited material for a wide variety of material compositions. The sacrificial buffer layer may be dissolved using an epitaxial liftoff technique in order to separate the semiconductor device from the spinel substrate, and the spinel substrate may be reused in the subsequent fabrication of other semiconductor devices.

Abstract: A strained silicon channel semiconductor structure comprises a substrate having an upper surface, a gate structure formed on the upper surface, at least one recess formed in the substrate at lateral sides of the gate structure, wherein the recess has at least one sidewall which has an upper sidewall and a lower sidewall concaved in the direction to the gate structure, and the included angle between the upper sidewall and horizontal plane ranges between 54.5°-90°, and an epitaxial layer filled into the two recesses.

Abstract: Semiconductor structures are provided comprising a substrate and a epitaxial layer formed over the substrate, wherein the epitaxial layer comprises B; and one or more element selected from the group consisting of Zr, Hf and Al and has a thickness greater than 50 nm. Further, methods for integrating Group III nitrides onto a substrate comprising, forming an epitaxial buffer layer of a diboride of Zr, Hf, Al, or mixtures thereof, over a substrate; and forming a Group III nitride layer over the buffer layer, are provided which serve to thermally decouple the buffer layer from the underlying substrate, thereby greatly reducing the strain induced in the semiconductor structures upon fabrication and/or operation.

Abstract: A contact structure for a semiconductor device includes a substrate comprising a major surface and a cavity. A bottom surface of the cavity is lower than the major surface. The contact structure also includes a strained material in the cavity, and a lattice constant of the strained material is different from lattice constant of the substrate. The contact structure also includes a first metal layer over the strained material, a dielectric layer over the first metal layer, and a second metal layer over the dielectric layer. The dielectric layer has a thickness ranging from 1 nm to 10 nm.

Abstract: A semiconductor structure and method for forming dielectric spacers and epitaxial layers for a complementary metal-oxide-semiconductor field effect transistor (CMOS transistor) are disclosed. Specifically, the structure and method involves forming dielectric spacers that are disposed in trenches and are adjacent to the silicon substrate, which minimizes leakage current. Furthermore, epitaxial layers are deposited to form source and drain regions, wherein the source region and drain regions are spaced at a distance from each other. The epitaxial layers are disposed adjacent to the dielectric spacers and the transistor body regions (i.e., portion of substrate below the gates), which can minimize transistor junction capacitance. Minimizing transistor junction capacitance can enhance the switching speed of the CMOS transistor.

Abstract: An AlGaN/GaN HEMT includes a compound semiconductor laminated structure, a gate electrode formed above the compound semiconductor laminated structure, and a p-type semiconductor layer formed between the compound semiconductor laminated structure and the gate electrode, and the p-type semiconductor layer has tensile strain in a direction parallel to a surface of the compound semiconductor laminated structure.

Abstract: A semiconductor device having tipless epitaxial source/drain regions and a method for its formation are described. In an embodiment, the semiconductor device comprises a gate stack on a substrate. The gate stack is comprised of a gate electrode above a gate dielectric layer and is above a channel region in the substrate. The semiconductor device also comprises a pair of source/drain regions in the substrate on either side of the channel region. The pair of source/drain regions is in direct contact with the gate dielectric layer and the lattice constant of the pair of source/drain regions is different than the lattice constant of the channel region. In one embodiment, the semiconductor device is formed by using a dielectric gate stack placeholder.

Abstract: A semiconductor device is disclosed. One embodiment includes a lateral HEMT (High Electron Mobility Transistor) structure with a heterojunction between two differing group III-nitride semiconductor compounds and a layer arranged on the heterojunction. The layer includes a group III-nitride semiconductor compound and at least one barrier to hinder current flow in the layer.

Abstract: Semiconductor devices and methods of manufacture thereof are disclosed. In one embodiment, a method of manufacturing a semiconductor device includes forming a channel region in a workpiece, and forming a source or drain region proximate the channel region. The source or drain region includes a contact resistance-lowering material layer comprising SiP, SiAs, or a silicide. The source or drain region also includes a channel-stressing material layer comprising SiCP or SiCAs.

Abstract: An embodiment is a structure comprising a substrate, a high energy bandgap material, and a high carrier mobility material. The substrate comprises a first isolation region and a second isolation region. Each of first and second isolation regions extends below a first surface of the substrate between the first and second isolation regions. The high energy bandgap material is over the first surface of the substrate and is disposed between the first and second isolation regions. The high carrier mobility material is over the high energy bandgap material. The high carrier mobility material extends higher than respective top surfaces of the first and second isolation regions to form a fin.

Abstract: A Field Effect Transistor (FET) structure may include a fin on a substrate having a first lattice constant and at least two different lattice constant layers on respective different axially oriented surfaces of the fin, wherein the at least two different lattice constant layers each comprise lattice constants that are different than the first lattice constant and each other.

Abstract: A method to form a strain-inducing semiconductor region is described. In one embodiment, formation of a strain-inducing semiconductor region laterally adjacent to a crystalline substrate results in a uniaxial strain imparted to the crystalline substrate, providing a strained crystalline substrate. In another embodiment, a semiconductor region with a crystalline lattice of one or more species of charge-neutral lattice-forming atoms imparts a strain to a crystalline substrate, wherein the lattice constant of the semiconductor region is different from that of the crystalline substrate, and wherein all species of charge-neutral lattice-forming atoms of the semiconductor region are contained in the crystalline substrate.

Abstract: Methods for improving the temperature performance of AlInGaP based light emitters. Nitrogen is added to the quantum wells in small quantities. Nitrogen is added in a range of about 0.5 percent to 2 percent. The addition of nitrogen increases the conduction band offset and increases the separation of the indirect conduction band. To keep the emission wavelength in a particular range, the concentration of In in the quantum wells may be decreased or the concentration of Al in the quantum wells may be increased. The net result is an increase in the conduction band offset and an increase in the separation of the indirect conduction band.

Abstract: A method for pseudomorphic growth and integration of an in-situ doped, strain-compensated metastable compound base into an electronic device, such as, for example, a SiGe NPN HBT, by substitutional placement of strain-compensating atomic species. The invention also applies to strained layers in other electronic devices such as strained SiGe, Si in MOS applications, vertical thin film transistors (VTFT), and a variety of other electronic device types. Devices formed from compound semiconductors other than SiGe, such as, for example, GaAs, InP, and AlGaAs are also amenable to beneficial processes described herein.

Abstract: A semiconductor device includes a substrate, a buffer layer, and a compound semiconductor layer. The buffer layer is configured by laminating two or more pairs of a first buffer and a second buffer. The first buffer is formed by laminating one or more pairs of an AlN layer and a GaN layer. The second buffer is formed of a GaN layer. A total Al composition of a pair of the first buffer and the second buffer on the compound semiconductor layer side is higher than that of a pair of the first buffer and the second buffer on the substrate side.

Abstract: The present disclosure provides a method of fabricating a semiconductor device that includes providing a semiconductor substrate, forming a trench in the substrate, where a bottom surface of the trench has a first crystal plane orientation and a side surface of the trench has a second crystal plane orientation, and epitaxially (epi) growing a semiconductor material in the trench. The epi process utilizes an etch component. A first growth rate on the first crystal plane orientation is different from a second growth rate on the second crystal plane orientation.

Abstract: Fabrication of monolithic lattice-mismatched semiconductor heterostructures with limited area regions having upper portions substantially exhausted of threading dislocations, as well as fabrication of semiconductor devices based on such lattice-mismatched heterostructures.

Abstract: A first p-type SiGe mixed crystal layer is formed by an epitaxial growth method in a trench, and a second p-type SiGe mixed crystal layer is formed. On the second SiGe mixed crystal layer, a third p-type SiGe mixed crystal layer is formed. The height of an uppermost surface of the first SiGe mixed crystal layer from the bottom of the trench is lower than the depth of the trench with the surface of the silicon substrate being the standard. The height of an uppermost surface of the second SiGe mixed crystal layer from the bottom of the trench is higher than the depth of the trench with the surface of the silicon substrate being the standard. Ge concentrations in the first and third SiGe mixed crystal layers are lower than a Ge concentration in the second SiGe mixed crystal layer.

Abstract: A high power, wide-bandgap device is disclosed that exhibits reduced junction temperature and higher power density during operation and improved reliability at a rated power density. The device includes a diamond substrate for providing a heat sink with a thermal conductivity greater than silicon carbide, a single crystal silicon carbide layer on the diamond substrate for providing a supporting crystal lattice match for wide-bandgap material structures that is better than the crystal lattice match of diamond, and a Group III nitride heterostructure on the single crystal silicon carbide layer for providing device characteristics.