Abstract: Electronic devices and methods of forming an electronic device are disclosed herein. An electronic device may include a first 2D atomic crystal layer; a second 2D atomic crystal layer disposed atop the first 2D atomic crystal layer; and an interface comprising van-der-Waals bonds between the first 2D atomic crystal layer and the second 2D atomic crystal layer. A method of forming an electronic device may include depositing a first 2D atomic crystal layer; and depositing a second 2D atomic crystal layer atop the first 2D atomic crystal layer; wherein an interface is formed between the first 2D atomic crystal layer and the second 2D atomic crystal layer via van-der-Waals bonding.

Abstract: Provided is a laminate containing a first compound semiconductor layer; and a second compound semiconductor layer integrally bonded to the first compound semiconductor layer via a bonding layer. A plane A is in the second compound semiconductor layer bonded to a surface where a plane B is in the first compound semiconductor layer, or a surface where a plane B is in the second compound semiconductor layer bonded to a surface where a plane A in the first compound semiconductor layer. The impurity concentration of the bonding layer is 2×1018 cm3 or more.

Abstract: A semiconductor device and a method for manufacturing the same are disclosed. The method comprises: forming at least one trench in a first semiconductor layer, wherein at least lower portions of respective sidewalls of the trench tilt toward outside of the trench; filling a dielectric material in the trench, thinning the first semiconductor layer so that the first semiconductor layer is recessed with respect to the dielectric material, and epitaxially growing a second semiconductor layer on the first semiconductor layer, wherein the first semiconductor layer and the semiconductor layer comprise different materials from each other. According to embodiments of the disclosure, defects occurring during the heteroepitaxial growth can be effectively suppressed.

Abstract: A semiconductor device is provided. The semiconductor device includes a semiconductor body having a main surface. In a vertical cross-section which is substantially orthogonal to the main surface the semiconductor body includes a vertical trench, an n-type silicon semiconductor region, and two p-type silicon semiconductor regions each of which adjoins the n-type silicon semiconductor region and is arranged between the n-type silicon semiconductor region and the main surface. The vertical trench extends from the main surface at least partially into the n-type silicon semiconductor region and includes a compound semiconductor region which includes silicon and germanium and is arranged between the two p-type silicon semiconductor regions. The compound semiconductor region and the two p-type silicon semiconductor regions include n-type dopants and p-type dopants.

Abstract: Gallium nitride (GaN) based semiconductor devices and methods of manufacturing the same. The GaN-based semiconductor device may include a heterostructure field effect transistor (HFET) or a Schottky diode, arranged on a heat dissipation substrate. The HFET device may include a GaN-based multi-layer having a recess region; a gate arranged in the recess region; and a source and a drain that are arranged on portions of the GaN-based multi-layer at two opposite sides of the gate (or the recess region). The gate, the source, and the drain may be attached to the heat dissipation substrate. The recess region may have a double recess structure. While such a GaN-based semiconductor device is being manufactured, a wafer bonding process and a laser lift-off process may be used.

Abstract: The present invention provides a method of forming a transistor. The method includes forming a first layer of a first semiconductor material above an insulation layer. The first semiconductor material is selected to provide high mobility to a first carrier type. The method also includes forming a second layer of a second semiconductor material above the first layer of semiconductor material. The second semiconductor material is selected to provide high mobility to a second carrier type opposite the first carrier type. The method further includes forming a first masking layer adjacent the second layer and etching the second layer through the first masking layer to form at least one feature in the second layer. Each feature in the second layer forms an inverted-T shape with a portion of the second layer.

Abstract: A semiconductor structure having a silicon substrate having a <111> crystallographic orientation, an insulating layer disposed over a first portion of the silicon substrate, a silicon layer having a <100> orientation disposed over the insulating layer, and a non-nitride column semiconductor layer or column II-VI semiconductor layer having the same <111> crystallographic orientation as the silicon substrate, the non-nitride column III-V semiconductor layer or column II-VI semiconductor layer being in direct contact with a second portion of the silicon substrate. A column III-nitride is disposed on the surface of the third portion of the substrate.

Abstract: Obtaining a structure comprised of first and second layers of a first semiconductor materials and a strain relief buffer (SRB) layer between the first and second layers, forming a sidewall spacer on the sidewalls of an opening in the second layer, and forming a third semiconductor material in the opening, wherein the first, second and third semiconductor materials are different. A device includes first and second layers of first and second semiconductor materials and an SRB layer positioned above the first layer. The second layer is positioned above a first portion of the SRB layer, a region of a third semiconductor material is in an opening in the second layer and above a second portion of the SRB layer, and an insulating material is positioned between the region comprised of the third semiconductor material and the second layer.

Abstract: A semiconductor structure includes a III-V monocrystalline layer and a germanium surface layer. An interlayer is formed directly between the III-V monocrystalline layer and the germanium surface layer from a material selected to provide stronger nucleation bonding between the interlayer and the germanium surface layer than nucleation bonding that would be achievable directly between the III-V monocrystalline layer and the germanium surface layer such that a continuous, relatively defect-free germanium surface layer is provided.

Abstract: A low voltage tunnel field effect transistor includes a p-n tunnel junction, a gate-dielectric, a gate, a source-contact, and a drain-contact. The p-n tunnel junction includes a depletion region interfacing together a source-layer and a drain-layer. The depletion region includes a source-tunneling-region of the source-layer and a drain-tunneling-region of the drain-layer. When no external electric field is imposed, the depletion region of the p-n tunnel junction has an internal electric field that substantially points towards the source-tunneling-region and the drain-tunneling-region. The gate-dielectric is interfaced directly onto the drain-tunneling-region such that the drain-tunneling-region is between the source-tunneling-region and the gate-dielectric. The gate is interfaced onto the gate-dielectric such that the gate is configured to impose an external electric field which is oriented substantially in parallel to the internal electric field of the depletion region.

Abstract: Methods for forming a HEMT device are provided. The method includes forming an ultra-thin barrier layer on the plurality of thin film layers. A dielectric thin film layer is formed over a portion of the ultra-thin barrier layer to leave exposed areas of the ultra-thin barrier layer. A SAG S-D thin film layer is formed over the exposed areas of the ultra-thin barrier layer while leaving the dielectric thin film layer exposed. The dielectric thin film layer is then removed to expose the underlying ultra-thin barrier layer. The underlying ultra-thin barrier layer is treating with fluorine to form a treated area. A source and drain is added on the SAG S-D thin film layer, and a dielectric coating is deposited over the ultra-thin barrier layer treated with fluorine such that the dielectric coating is positioned between the source and the drain.

Abstract: A method for forming a double step surface on a semiconductor substrate includes, with an etching process used in a Metal-Organic Chemical Vapor Deposition (MOCVD) process, forming a rough surface on a region of a semiconductor substrate. The method further includes, with an annealing process used in the MOCVD process, forming double stepped surface on the region of the semiconductor substrate.

Abstract: A nitride semiconductor substrate suitable for a normally-off type high breakdown-voltage device and a method of manufacturing the substrate are provided allowing both a higher threshold voltage and improvement in current collapse. In a nitride semiconductor substrate 10 having a substrate 1, a buffer layer 2 formed on one principal plane of the substrate 1, an intermediate layer 3 formed on the buffer layer 2, an electron transport layer 4 formed on the intermediate layer 3, and an electron supply layer 5 formed on the electron transport layer 4, the intermediate layer 3 has a thickness of 200 nm to 1500 nm and a carbon concentration of 5×1016 atoms/cm3 to 1×1018 atoms/cm3 and is of AlxGa1-xN (0.05?x?0.24), and the electron transport layer 4 has a thickness of 5 nm to 200 nm and is of AlyGa1-yN (0?y?0.04).

Abstract: To provide a semiconductor device in which a rectifying element capable of reducing a leak current in reverse bias when a high voltage is applied and reducing a forward voltage drop Vf and a transistor element are integrally formed on a single substrate. A semiconductor device has a transistor element and a rectifying element on a single substrate. The transistor element has an active layer formed on the substrate and three electrodes (source electrode, drain electrode, and gate electrode) disposed on the active layer. The rectifying element has an anode electrode disposed on the active layer, a cathode electrode which is the drain electrode, and a first auxiliary electrode between the anode electrode and cathode electrode.

Abstract: Methods of fabricating semiconductor devices or structures include bonding a layer of semiconductor material to another material at a temperature, and subsequently changing the temperature of the layer of semiconductor material. The another material may be selected to exhibit a coefficient of thermal expansion such that, as the temperature of the layer of semiconductor material is changed, a controlled and/or selected lattice parameter is imparted to or retained in the layer of semiconductor material. In some embodiments, the layer of semiconductor material may comprise a III-V type semiconductor material, such as, for example, indium gallium nitride. Novel intermediate structures are formed during such methods. Engineered substrates include a layer of semiconductor material having an average lattice parameter at room temperature proximate an average lattice parameter of the layer of semiconductor material previously attained at an elevated temperature.

Abstract: The objective is to improve capabilities such as high-speed switching of a compound semiconductor device. Provided is a semiconductor wafer comprising a silicon wafer; an insulating film that is formed on the silicon wafer and that has an open portion reaching the silicon wafer; a Ge crystal formed in the open portion; a seed compound semiconductor crystal that is grown with the Ge crystal as a nucleus and that protrudes beyond a surface of the insulating film; and a laterally grown compound semiconductor layer that is laterally grown on the insulating film with a specified surface of the seed compound semiconductor crystal as a seed surface.

Abstract: An embodiment concerns forming an EPI film on a substrate where the EPI film has a different lattice constant from the substrate. The EPI film and substrate may include different materials to collectively form a hetero-epitaxial device having, for example, a Si and/or SiGe substrate and a III-V or IV film. The EPI film may be one of multiple EPI layers or films and the films may include different materials from one another and may directly contact one another. Further, the multiple EPI layers may be doped differently from another in terms of doping concentration and/or doping polarity. One embodiment includes creating a horizontally oriented hetero-epitaxial structure. Another embodiment includes a vertically oriented hetero-epitaxial structure. The hetero-epitaxial structures may include, for example, a bipolar junction transistor, heterojunction bipolar transistor, thyristor, and tunneling field effect transistor among others. Other embodiments are described herein.

Abstract: A layer in which the potential level difference normally unrequired for device operation is generated is positively inserted in a device structure. The potential level difference has such a function that even if a semiconductor having a small bandgap is exposed on a mesa side surface, a potential drop amount of the portion is suppressed, and a leakage current inconvenient for device operation can be reduced. This effect can be commonly obtained for a heterostructure bipolar transistor, a photodiode, an electroabsorption modulator, and so on. In the photodiode, since the leakage current is alleviated, the device size can be reduced, so that in addition to improvement of operating speed with a reduction in series resistance, it is advantageous that the device can be densely disposed in an array.

Abstract: The present invention discloses a semiconductor composite film with a heterojunction and a manufacturing method thereof. The semiconductor composite film includes: a semiconductor substrate; and a semiconductor epitaxial layer, which is formed on the semiconductor substrate, and it has a first surface and a second surface opposite to each other, wherein the heterojunction is formed between the first surface and the semiconductor substrate, and wherein the semiconductor epitaxial layer further includes at least one recess, which is formed by etching the semiconductor epitaxial layer from the second surface toward the first surface. The recess is for mitigating a strain in the semiconductor composite film.

Abstract: A device includes a substrate, isolation regions at a surface of the substrate, and a semiconductor region over a top surface of the isolation regions. A conductive feature is disposed over the top surface of the isolation regions, wherein the conductive feature is adjacent to the semiconductor region. A dielectric material is disposed between the conductive feature and the semiconductor region. The dielectric material, the conductive feature, and the semiconductor region form an anti-fuse.

Abstract: To provide a semiconductor device including a functional laminate having flatness and crystallinity improved by effectively passing on the crystallinity and flatness improved in a buffer to the functional laminate, and to provide a method of producing the semiconductor device; in the semiconductor device including the buffer and the functional laminate having a plurality of nitride semiconductor layers, the functional laminate includes a first n-type or i-type AlxGa1-xN layer (0?x<1) on the buffer side, and an AlzGa1-zN adjustment layer containing p-type impurity, which has an approximately equal Al composition to the first AlxGa1-xN layer (x?0.05?z?x+0.05, 0?z<1) is provided between the buffer and the functional laminate.

Abstract: A semiconductor switching arrangement includes a normally on semiconductor component of a first conduction type and a normally off semiconductor component of a second conduction type which is the complement of the first conduction type. A load path of the normally off semiconductor component is connected in series with the load path of the normally on semiconductor component. A first actuation circuit connected between the control connection of the normally on semiconductor component and a load path connection of the normally on semiconductor component. The load path connection of the normally on semiconductor component is arranged between the normally on and normally off semiconductor components. A second actuation circuit is connected between the control connection of the normally off semiconductor component and a load path connection of the normally off semiconductor component.

Abstract: A GaN-based semiconductor element includes a substrate, a buffer layer formed on the substrate, including an electrically conductive portion, an epitaxial layer formed on the buffer layer, and a metal structure in ohmic contact with the electrically conductive portion of the buffer layer for controlling an electric potential of the buffer layer.

Abstract: A III-nitride semiconductor device which includes a charged gate insulation body.

Abstract: A bridge structure for use in a semiconductor device includes a semiconductor substrate and a semiconductor structure layer. The semiconductor structure layer is formed on a surface of the semiconductor substrate and a lattice difference is formed between the semiconductor structure layer and the semiconductor substrate. The semiconductor structure layer includes at least a first block, at least a second block and at least a third block, wherein the first block and the third block are bonded on the surface of the semiconductor substrate, the second block is floated over the semiconductor substrate and connected with the first block and the third block.

Abstract: Formulations for voltage switchable dielectric materials include two or more different types of semiconductive materials uniformly dispersed within a dielectric matrix material. The semiconductive materials are selected to have different bandgap energies in order to provide the voltage switchable dielectric material with a stepped voltage response. The semiconductive materials may comprise inorganic particles, organic particles, or an organic material that is soluble in, or miscible with, the dielectric matrix material. Formulations optionally can also include electrically conductive materials. At least one of the conductive or semiconductive materials in a formulation can comprise particles characterized by an aspect ratio of at least 3 or greater.

Abstract: A semiconductor device having a tunable capacitance is disclosed, comprising a substrate, a semiconductor base layer comprising a first semiconductor material having a first band-gap, and a plurality of successive semiconductor layers positioned between the substrate and the semiconductor base layer. The plurality of successive semiconductor layers includes a tuning layer comprising a second semiconductor material having a second band-gap larger than the first band-gap. Furthermore, the tuning layer has a non-uniform doping profile with doping concentration that varies in accordance with distance from a surface of the tuning layer proximal to the semiconductor base layer. The tunable capacitance of the semiconductor device varies in accordance with an applied voltage between the base layer and one of the successive semiconductor layers.

Abstract: Disclosed herein is a semiconductor device including: a base substrate; a first nitride semiconductor layer formed on the base substrate; a second nitride semiconductor layer formed on the first nitride semiconductor layer; a cathode electrode formed on one side of the second nitride semiconductor layer; an anode electrode having one end and the other end, one end being recessed at the other side of the second nitride semiconductor layer up to a predetermined depth, and the other end being spaced apart from the cathode electrode and formed to be extended up to an upper portion of the cathode electrode; and an insulating film formed on the second nitride semiconductor layer between the anode electrode and the cathode electrode so as to cover the cathode electrode.

Abstract: To provide an epitaxial substrate for electronic devices, in which current flows in a lateral direction, which enables accurate measurement of the sheet resistance of HEMTs without contact, and to provide a method of efficiently producing the epitaxial substrate for electronic devices, the method characteristically includes the steps of forming a barrier layer against impurity diffusion on one surface of a high-resistance Si-single crystal substrate, forming a buffer as an insulating layer on the other surface of the high-resistance Si-single crystal substrate, producing an epitaxial substrate by epitaxially growing a plurality of III-nitride layers on the buffer to form a main laminate, and measuring resistance of the main laminate of the epitaxial substrate without contact.

Abstract: An electronic device includes a substrate supporting mobile charge carriers, insulative features formed on the substrate surface to define first and second substrate areas on either side of the insulative features, the first and second substrate areas being connected by an elongate channel defined by the insulative features, the channel providing a charge carrier flow path in the substrate from the first area to the second area, the conductivity between the first and second substrate areas being dependent upon the potential difference between the areas. The mobile charge carriers can be within at least two modes in each of the three dimensions within the substrate. The substrate can be an organic material. The mobile charge carriers can have a mobility within the range 0.01 cm2/Vs to 100 cm2/Vs, and the electronic device may be an RF device. Methods for forming such devices are also described.

Abstract: Devices and methods for providing JFET transistors with improved operating characteristics are provided. Specifically, one or more embodiments of the present invention relate to JFET transistors with a higher diode turn-on voltage. For example, one or more embodiments include a JFET with a PIN gate stack. One or more embodiments also relate to systems and devices in which the improved JFET may be employed, as well as methods of manufacturing the improved JFET.

Abstract: Semiconductor devices and methods for making semiconductor devices are disclosed herein. A method configured in accordance with a particular embodiment includes forming a stack of semiconductor materials from an epitaxial substrate, where the stack of semiconductor materials defines a heterojunction, and where the stack of semiconductor materials and the epitaxial substrate further define a bulk region that includes a portion of the semiconductor stack adjacent the epitaxial substrate. The method further includes attaching the stack of semiconductor materials to a carrier, where the carrier is configured to provide a signal path to the heterojunction. The method also includes exposing the bulk region by removing the epitaxial substrate.

Abstract: Fast turn on silicon controlled rectifiers for ESD protection. A semiconductor device includes a semiconductor substrate of a first conductivity type; a first well of a second conductivity type; a second well of the second conductivity type; a first diffused region of the first conductivity type and coupled to a first terminal; a first diffused region of the second conductivity type; a second diffused region of the first conductivity type; a second diffused region of the second conductivity type in the second well; wherein the first diffused region of the first conductivity type and the first diffused region of the second conductivity type form a first diode, and the second diffused region of the first conductivity type and the second diffused region of the second conductivity type form a second diode, and the first and second diodes are series coupled between the first terminal and the second terminal.

Abstract: Semiconductor structures and methods of manufacture semiconductors are provided which relate to heterojunction bipolar transistors. The structure includes two devices connected by metal wires on a same wiring level. The metal wire of a first of the two devices is formed by selectively forming a metal cap layer on copper wiring structures.

Abstract: A structure comprises a substrate, a mask, a buffer/nucleation layer, and a group III-V compound semiconductor material. The substrate has a top surface and has a recess from the top surface. The recess includes a sidewall. The first mask is the top surface of the substrate. The buffer/nucleation layer is along the sidewall, and has a different material composition than a material composition of the sidewall. The III-V compound semiconductor material continuously extends from inside the recess on the buffer/nucleation layer to over the first mask.

Abstract: The interface resistance between the source/drain and gate of an HFET may be significantly reduced by engineering the bandgap of the 2DEG outside a gate region such that the charge density is substantially increased. The resistance may be further reduced by using an n+GaN Cap layer over the channel layer and barrier layer such that a horizontal surface of the barrier layer beyond the gate region is covered by the n+GaN Cap layer. This technique is applicable to depletion and enhancement mode HFETs.

Abstract: There is provided a semiconductor wafer including a base wafer, an insulating layer, and a Si crystal layer in the stated order. The semiconductor wafer further includes an inhibition layer that is provided on the Si crystal layer and has an opening penetrating therethrough to reach the Si crystal layer. The inhibition layer inhibiting crystal growth of a compound semiconductor. Furthermore, a seed crystal is provided within the opening, and a compound semiconductor has a lattice match or a pseudo lattice match with the seed crystal.

Abstract: According to one embodiment, a semiconductor wafer includes a substrate, an AlN buffer layer, a foundation layer, a first high Ga composition layer, a high Al composition layer, a low Al composition layer, an intermediate unit and a second high Ga composition layer. The first layer is provided on the foundation layer. The high Al composition layer is provided on the first layer. The low Al composition layer is provided on the high Al composition layer. The intermediate unit is provided on the low Al composition layer. The second layer is provided on the intermediate unit. The first layer has a first tensile strain and the second layer has a second tensile strain larger than the first tensile strain. Alternatively, the first layer has a first compressive strain and the second layer has a second compressive strain smaller than the first compressive strain.

Abstract: A compound semiconductor device includes as compound semiconductor layers: a first layer; a second layer larger in band gap than the first layer, formed above the first layer; a third layer having a p-type conductivity type, formed above the second layer; a gate electrode formed above the second layer via the third layer; a fourth layer larger in band gap than the second layer, formed to be in contact with the third layer above the second layer; and a fifth layer smaller in band gap than the fourth layer, formed to be in contact with the third layer above the fourth layer.

Abstract: Methods for integrating wide-gap semiconductors, and specifically, gallium nitride epilayers with synthetic diamond substrates are disclosed. Diamond substrates are created by depositing synthetic diamond onto a nucleating layer deposited or formed on a layered structure that comprises at least one layer made out of gallium nitride. Methods for manufacturing GaN-on-diamond wafers with low bow and high crystalline quality are disclosed along with preferred choices for manufacturing GaN-on-diamond wafers and chips tailored to specific applications.

Abstract: A semiconductor light emitting device (10) comprises a semiconductor structure (12) comprising a first body (14) of a first semiconductor material (in this case Ge) comprising a first region of a first doping kind (in this case n) and a second body (18) of a second semiconductor material (in this case Si) comprising a first region of a second doping kind (in this case p). The structure comprises a junction region (15) comprising a first heterojunction (16) formed between the first body (14) and the second body (18) and a pn junction (17) formed between regions of the structure of the first and second doping kinds respectively. A biasing arrangement (20) is connected to the structure for, in use, reverse biasing the pn junction, thereby to cause emission of light.

Abstract: A light emitting diode (LED) and a method for fabricating the same, capable of improving brightness by forming a InGaN layer having a low concentration of indium, and whose lattice constant is similar to that of an active layer of the LED, is provided. The LED includes: a buffer layer disposed on a sapphire substrate; a GaN layer disposed on the buffer layer; a doped GaN layer disposed on the GaN layer; a GaN layer having indium disposed on the GaN layer; an active layer disposed on the GaN layer having indium; and a P-type GaN disposed on the active layer. Here, an empirical formula of the GaN layer having indium is given by In(x)Ga(1?x)N and a range of x is given by 0<x<2, and a thickness of the GaN layer having indium is 50-200 ?.

Abstract: In some embodiments, a metal insulator semiconductor heterostructure field effect transistor (MISHFET) is disclosed that has a source, a drain, an insulation layer, a gate dielectric, and a gate. The source and drain are on opposing sides of a channel region of a channel layer. The channel region is an upper portion of the channel layer. The channel layer comprises gallium nitride. The insulation layer is over the channel layer and has a first portion and a second portion. The first portion is nearer the drain than the source and has a first thickness. The second portion is nearer the source than drain and has the first thickness. The insulation layer has an opening through the insulation layer. The opening is between the first portion and the second portion.

Abstract: A semiconductor device includes: a substrate comprised of gallium nitride; an active layer provided on the substrate; a first buffer layer that is provided between the substrate and the active layer and is comprised of indium aluminum nitride (InxAl1?xN, 0.15?x?0.2); and a spacer layer that is provided between the first buffer layer and the active layer and is comprised of aluminum nitride having a thickness of 1 nm or more to 10 nm or less.

Abstract: An improved structure of the high electron mobility transistor (HEMT) and a fabrication method thereof are disclosed. The improved HEMT structure comprises a substrate, a channel layer, a spacing layer, a carrier supply layer, a Schottky layer, a first etch stop layer, a first n type doped layer formed by AlxGa1-xAs, and a second n type doped layer. The fabrication method comprises steps of: etching a gate, a drain, and a source recess by using a multiple selective etching process. Below the gate, the drain, and the source recess is the Schottky layer. A gate electrode is deposited in the gate recess to form Schottky contact. A drain electrode and a source electrode are deposited to form ohmic contacts in the drain recess and the source recess respectively, and on the second n type doped layer surrounding the drain recess and the source recess respectively.

Abstract: The product of the breakdown voltage (BVCEO) and the cutoff frequency (fT) of a SiGe heterojunction bipolar transistor (HBT) is increased beyond the Johnson limit by utilizing a doped region with a hollow core that extends down from the base to the heavily-doped buried collector region. The doped region and the buried collector region have opposite dopant types.

Abstract: A high brightness III-Nitride based Light Emitting Diode (LED), comprising multiple surfaces covered by Zinc Oxide (ZnO) layers, wherein the ZnO layers are grown in a low temperature aqueous solution and each have a (0001) c-orientation and a top surface that is a (0001) plane.

Abstract: A low-defect gallium nitride structure including a first gallium nitride layer comprising a plurality of gallium nitride columns etched into the first gallium nitride layer and a first dislocation density; and a second gallium nitride layer that extends over the gallium nitride columns and comprises a second dislocation density, wherein the second dislocation density may be lower than the first dislocation density. In addition, a method for fabricating a gallium nitride semiconductor layer that includes masking an underlying gallium nitride layer with a mask that comprises an array of columns and growing the underlying gallium nitride layer through the columns and onto said mask using metal-organic chemical vapor deposition pendeo-epitaxy to thereby form a pendeo-epitaxial gallium nitride layer coalesced on said mask to form a continuous pendeo-epitaxial monocrystalline gallium nitride semiconductor layer.

Abstract: A semiconductor device is disclosed comprising: a substrate having a surface comprising germanium; a layer of gallium on said surface; and a layer of gallium arsenide on the gallium covered surface. The semiconductor heterostructure of gallium arsenide on germanium is fabricated by the steps of: protecting by a shutter a surface comprising germanium in an environment having a partial pressure of arsenic less than 10?8torr; epitaxially growing a layer of gallium on the said surface immediately after exposure of said surface; and epitaxially growing a layer of gallium arsenide on the gallium covered surface.

Abstract: A hetero-junction tunneling transistor having a first layer of p++ silicon germanium which forms a source for the transistor at one end. A second layer of n+ silicon material is deposited so that a portion of the second layer overlies the first layer and forms the drain for the transistor. An insulating layer and metallic gate for the transistor is deposited on top of the second layer so that the gate is aligned with the overlying portions of the first and second layers. The gate voltage controls the conduction between the source and the drain and the conduction between the first and second layers occurs by vertical tunneling between the layers.