Abstract: A solar cell element is disclosed. The solar cell element comprises a semiconductor substrate, a first electrode, a second electrode, a first wiring member and a second wiring member. The semiconductor substrate with a first surface and a second surface comprises a plurality of through-holes. The first electrode comprises a plurality of conduction portions and at least one first output extracting portion. The second electrode has a resistivity of less than 2.5×10-8 ?m (ohm-meter). The first wiring member comprises a first end face in a long direction thereof. The second wiring member comprises a second end face in a long direction thereof facing the first end face.

Abstract: Substrates for an electronic circuit and device manufacturing methods are disclosed. According to an embodiment, the substrate comprises: a silicon or germanium wafer impregnated with impurities that form one or more deep energy levels within the band gap of the material forming the wafer, wherein at least one of said deep energy levels is positioned at least 0.3 eV away from the conduction band if the level is a donor level or at least 0.3 eV away from the valence band if the level is an acceptor level; and a device layer formed on a surface of said wafer, said device layer comprising electronically functional components formed in a layer of Periodic Table Group III-V or II-VI material. The wafer may be formed from Cz silicon or Cz germanium, for example.

Abstract: The present invention describes a hybrid integrated circuit comprising both CMOS and III-V devices, monolithically integrated in a single chip. It allows the almost complete elimination of the contamination issues related to the integration of different technologies, maintaining at the same time a good planarization of the structure. It further simplifies the fabrication process, allowing the growth of high quality III-V materials on (100) silicon substrates lowering the manufacturing cost. Moreover, differently from many prior art attempts, it does not require silicon on insulator technologies and/or other expensive process steps. This invention enables the consolidation on the same integrated circuit of a hybrid switching power converter that takes advantage of the established circuit topologies of CMOS circuitries and of the higher mobility and voltage withstanding of III-V HEMT devices.

Abstract: A sensor includes: a base wafer containing silicon; a seed member provided directly or indirectly on the base wafer; and a photothermal absorber that is made of a Group 3-5 compound semiconductor lattice-matching or pseudo lattice-matching the seed member and being capable of generating a carrier upon absorbing light or heat, where the photothermal absorber outputs an electric signal in response to incident light to be introduced into the photothermal absorber or heat to be applied to the photothermal absorber. A semiconductor wafer includes: a base wafer containing silicon; a seed member provided directly or indirectly on the base wafer; and a photothermal absorber that is made of a Group 3-5 compound semiconductor lattice-matching or pseudo lattice-matching the seed member and being capable of generating a carrier upon absorbing light or heat.

Abstract: In an exemplary implementation, a method includes growing a III-Nitride body over a group IV substrate in a semiconductor wafer. The method includes forming at least one device layer over the III-Nitride body. The method also includes etching grid array trenches in the III-Nitride body, where the etching of the grid array trenches may extend into the group IV substrate. The method can also include forming an edge trench around a perimeter of the semiconductor wafer. The method further includes forming separate dies by cutting the semiconductor wafer approximately along the grid array trenches.

Abstract: A method of forming a template on a silicon substrate includes providing a single crystal silicon substrate. The method further includes epitaxially depositing a layer of rare earth oxide on the surface of the silicon substrate. The rare earth oxide being substantially crystal lattice matched to the surface of the silicon substrate. The method further includes forming an aluminum oxide layer on the rare earth oxide, the aluminum oxide being substantially crystal lattice matched to the surface of the rare earth oxide and epitaxially depositing a layer of aluminum nitride (AlN) on the aluminum oxide layer substantially crystal lattice matched to the surface of the aluminum oxide.

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 High Electron Mobility Transistor (HEMT) includes a first III-V compound layer having a first band gap, and a second III-V compound layer having a second band gap over the first III-V compound layer. The second band gap is greater than the first band gap. A crystalline interfacial layer is overlying and in contact with the second III-V compound layer. A gate dielectric is over the crystalline interfacial layer. A gate electrode is over the gate dielectric. A source region and a drain region are over the second III-V compound layer, and are on opposite sides of the gate electrode.

Abstract: A direct wafer bonding process for joining GaN and silicon substrates involves pre-treating each of the wafers in an ammonia plasma in order to render the respective contact surfaces ammophilic. The GaN substrate and the silicon substrate may each comprise single crystal wafers. The resulting hybrid semiconductor structure can be used to form high quality, low cost LEDs.

Abstract: A Gallium Nitride (GaN) series of devices—transistors and diodes are disclosed—that have greatly superior current handling ability per unit area than previously described GaN devices. The improvement is due to improved layout topology. The devices also include a simpler and superior flip chip connection scheme and a means to reduce the thermal resistance. A simplified fabrication process is disclosed and the layout scheme which uses island electrodes rather than finger electrodes is shown to increase the active area density by two to five times that of conventional interdigitated structures. Ultra low on resistance transistors and very low loss diodes can be built using the island topology. Specifically, the present disclosure provides a means to enhance cost/effective performance of all lateral GaN structures.

Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a semiconductor substrate, a first gate insulating film, a charge storage layer, a second gate insulating film, and a control gate electrode. The first gate insulating film is arranged on the semiconductor substrate. The charge storage layer is arranged on the first gate insulating film, and includes aluminum and silicon. The second gate insulating film is arranged on the charge storage layer, and includes aluminum, silicon, and lanthanum. The control gate electrode is arranged on the second gate insulating film.

Abstract: A semiconductor wafer has a plurality of optical semiconductor devices (namely, semiconductor lasers) which are formed from epitaxially grown layers and arranged across the surface of the semiconductor wafer. The InGaAs epitaxial layer of the semiconductor wafer has an opening (or groove) which continuously extends along and between the plurality of optical semiconductor devices, and which exposes the layer underlying the InGaAs epitaxial layer to at least the layer overlying the InGaAs epitaxial layer. The semiconductor wafer may be scribed along this opening to form a vertically extending crack therein.

Abstract: It is an object to provide a photoelectric conversion device with high photoelectric conversion efficiency. The photoelectric conversion device includes an electrode layer, and a light absorbing layer located on the electrode layer. The light absorbing layer is comprised of a plurality of stacked semiconductor layers containing a chalcopyrite-based compound semiconductor. The semiconductor layers contain oxygen. A molar concentration of the oxygen in surfaces and their vicinities of the semiconductor layers where the semiconductor layers are stacked on each other is higher than average molar concentrations of the oxygen in the semiconductor layers.

Abstract: A method for transferring a layer of semiconductor by providing a donor substrate that includes a useful layer of a semiconductor material, a confinement structure that includes a confinement layer of a semiconductor material having a chemical composition that is different than that of the useful layer, and two protective layers of semiconductor material that is distinct from the confinement layer with the protective layers being arranged on both sides of the confinement layer; introducing ions into the donor substrate, bonding the donor substrate to a receiver substrate, subjecting the donor and receiver substrates to a heat treatment that provides an increase in temperature during which the confinement layer attracts the ions in order to concentrate them in the confinement layer, and detaching the donor substrate from the receiver substrate by breaking the confinement layer.

Abstract: A semiconductor chip includes a magnetic storage device and includes an electrode pad on a first face. The semiconductor chip is coated with a magnetic shield layer in a state in which at least the electrode pad is exposed. The semiconductor chip is mounted on an interconnect substrate through a bump. At least one of the semiconductor chip and the interconnect substrate includes a convex portion, and the bump is disposed over the convex portion.

Abstract: A light emitting device includes a conductive substrate, a plurality of light emitting cells disposed on the conductive substrate, wherein each of the plurality of light emitting device cells includes a first semiconductor layer, a second semiconductor layer, and an active layer between the first semiconductor layer and the second semiconductor layer, a protective layer disposed to cover a side of the first semiconductor layer and a side of the active layer, and a first electrode for connecting the second semiconductor layers of more than one of the light emitting cells to each other, wherein the protective layer includes protruding portions extending to an inside of each of the light emitting cells from the side of the first semiconductor layer and the side of the active layer.

Abstract: Quantum-well-based semiconductor devices and methods of forming quantum-well-based semiconductor devices are described. A method includes providing a hetero-structure disposed above a substrate and including a quantum-well channel region. The method also includes forming a source and drain material region above the quantum-well channel region. The method also includes forming a trench in the source and drain material region to provide a source region separated from a drain region. The method also includes forming a gate dielectric layer in the trench, between the source and drain regions; and forming a gate electrode in the trench, above the gate dielectric layer.

Abstract: In a manufacturing method of a semiconductor device, first, a first semiconductor layer, a second semiconductor layer, and a p-type third semiconductor layer are sequentially epitaxially grown on a substrate. After that, the third semiconductor layer is selectively removed. Then, a fourth semiconductor layer is epitaxially grown on the second semiconductor layer. Then, a gate electrode is formed on the third semiconductor layer.

Abstract: The present invention discloses a high electron mobility transistor (HEMT) and a manufacturing method thereof. The HEMT includes a semiconductor layer, a barrier layer on the semiconductor layer, a piezoelectric layer on the barrier layer, a gate on the piezoelectric layer, and a source and a drain at two sides of the gate respectively, wherein each bandgap of the semiconductor layer, the barrier layer, and the piezoelectric layer partially but not entirely overlaps the other two bandgaps. The gate is formed for receiving a gate voltage. A two dimensional electron gas (2DEG) is formed in a portion of a junction between the semiconductor layer and the barrier layer but not below at least a portion of the piezoelectric layer, wherein the 2DEG is electrically connected to the source and the drain.

Abstract: Solid-state imaging device of the present invention is a backside-illumination-type solid-state imaging device including wiring layer formed on first surface side of semiconductor substrate; and light receiving section that photoelectrically converts light incident from second surface side that is opposite from first surface side, wherein spontaneous polarization film formed of a material having spontaneous polarization is formed on a light receiving surface of light receiving section. Accordingly, a hole accumulation layer can be formed on the light receiving surface of light receiving section, and a dark current can be suppressed.

Abstract: A group III nitride semiconductor crystal substrate has a diameter of at least 25 mm and not more than 160 mm. The resistivity of the group III nitride semiconductor crystal substrate is at least 1×10?4 ?·cm and not more than 0.1 ?·cm. The resistivity distribution in the diameter direction of the group III nitride semiconductor crystal is at least ?30% and not more than 30%. The resistivity distribution in the thickness direction of the group III nitride semiconductor crystal is at least ?16% and not more than 16%.

Abstract: Solid state lighting devices with semi-polar or non-polar surfaces and associated methods of manufacturing are disclosed herein. In one embodiment, a solid state lighting device includes a substrate material having a substrate surface and an epitaxial silicon structure in direct contact with the substrate surface. The epitaxial silicon structure has a sidewall extending away from the substrate surface. The solid state lighting device also includes a semiconductor material on at least a portion of the sidewall of the epitaxial silicon structure. The semiconductor material has a semiconductor surface that is spaced apart from the substrate surface and is located on a semi-polar or non-polar crystal plane of the semiconductor material.

Abstract: A transistor includes a trench formed in a semiconductor body, the trench having sidewalls and a bottom. The transistor further includes a first semiconductor material disposed in the trench adjacent the sidewalls and a second semiconductor material disposed in the trench and spaced apart from the sidewalls by the first semiconductor material. The second semiconductor material has a different band gap than the first semiconductor material. The transistor also includes a gate material disposed in the trench and spaced apart from the first semiconductor material by the second semiconductor material. The gate material provides a gate of the transistor. Source and drain regions are arranged in the trench with a channel interposed between the source and drain regions in the first or second semiconductor material so that the channel has a lateral current flow direction along the sidewalls of the trench.

Abstract: An assembly and method of making same are provided. The assembly can be formed by stacking a first semiconductor element atop a second semiconductor element and forming an electrically conductive element extending through openings of the semiconductor elements. The openings may be staged. The conductive element can conform to contours of the interior surfaces of the openings and can electrically connect conductive pads of the semiconductor elements. A dielectric region can be provided at least substantially filling the openings of the semiconductor elements, and the electrically conductive element can extend through an opening formed in the dielectric region.

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: A DBR/gallium nitride/aluminum nitride base grown on a silicon substrate includes a Distributed Bragg Reflector (DBR) positioned on the silicon substrate. The DBR is substantially crystal lattice matched to the surface of the silicon substrate. A first layer of III-N material is positioned on the surface of the DBR, an inter-layer of aluminum nitride (AlN) is positioned on the surface of the first layer of III-N material and an additional layer of III-N material is positioned on the surface of the inter-layer of aluminum nitride. The inter-layer of aluminum nitride and the additional layer of III-N material are repeated n-times to reduce or engineer strain in a final III-N layer.

Abstract: A method for forming a nanowire field effect transistor (FET) device includes forming a nanowire on a semiconductor substrate, forming a first gate structure on a first portion of the nanowire, forming a first protective spacer adjacent to sidewalls of the first gate structure and over portions of the nanowire extending from the first gate structure, removing exposed portions of the nanowire left unprotected by the first spacer, and epitaxially growing a doped semiconductor material on exposed cross sections of the nanowire to form a first source region and a first drain region.

Abstract: The present disclosure involves an apparatus. The apparatus includes a substrate having a front side a back side opposite the front side. The substrate includes a plurality of openings formed from the back side of the substrate. The openings collectively define a pattern on the back side of the substrate from a planar view. In some embodiments, the substrate is a silicon substrate or a silicon carbide substrate. Portions of the silicon substrate vertically aligned with the openings have vertical dimensions that vary from about 100 microns to about 300 microns. A III-V group compound layer is formed over the front side of the silicon substrate. The III-V group compound layer is a component of one of: a light-emitting diode (LED), a laser diode (LD), and a high-electron mobility transistor (HEMT).

Abstract: A device-embedded flexible printed circuit board (FPCB) and a method of manufacturing the device-embedded FPCB are provided. The device-embedded FPCB includes: a first conductive layer; a first insulating layer which is disposed on the first conductive layer and includes at least one bump hole and at least one groove; a first plating layer which is formed in the at least one groove of the first insulating layer; and a device which includes at least one bump which is inserted into the at least one bump hole to be connected to the first conductive layer.

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: 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: Electrical contact to the front side of a photovoltaic cell is provided by an array of conductive through-substrate vias, and optionally, an array of conductive blocks located on the front side of the photovoltaic cell. A dielectric liner provides electrical isolation of each conductive through-substrate via from the semiconductor material of the photovoltaic cell. A dielectric layer on the backside of the photovoltaic cell is patterned to cover a contiguous region including all of the conductive through-substrate vias, while exposing a portion of the backside of the photovoltaic cell. A conductive material layer is deposited on the back surface of the photovoltaic cell, and is patterned to form a first conductive wiring structure that electrically connects the conductive through-substrate vias and a second conductive wiring structure that provides electrical connection to the backside of the photovoltaic cell.

Abstract: According to one embodiment, a nitride semiconductor device includes a first, a second and a third semiconductor layer, a first and a second main electrode and a control electrode. The first layer made of a nitride semiconductor of a first conductivity type is provided on a substrate. The second layer made of a nitride semiconductor of a second conductivity type is provided on the first layer. The third layer made of a nitride semiconductor is provided on the second layer. The first electrode is electrically connected with the second layer. The second electrode is provided at a distance from the first electrode and electrically connected with the second layer. The control electrode is provided within a first trench via an insulating film. The first trench is disposed between the first and the second main electrodes, penetrates the third and the second layers, and reaches the first layer.

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: There is provided a method of forming a nitride semiconductor layer, including the steps of firstly providing a substrate on which a patterned epitaxy layer with a pier structure is formed. A protective layer is then formed on the patterned epitaxy layer, exposing a top surface of the pier structure. Next, a nitride semiconductor layer is formed over the patterned epitaxy layer connected to the nitride semiconductor layer through the pier structure, wherein the nitride semiconductor layer, the pier structure, and the patterned epitaxy layer together form a space exposing a bottom surface of the nitride semiconductor layer. Thereafter, a weakening process is performed to remove a portion of the bottom surface of the nitride semiconductor layer and to weaken a connection point between the top surface of the pier structure and the nitride semiconductor layer. Finally, the substrate is separated from the nitride semiconductor layer through the connection point.

Abstract: According to one disclosed embodiment, a monolithic vertically integrated composite device comprises a double sided semiconductor substrate having first and second sides, a group IV semiconductor layer formed over the first side and comprising at least one group IV semiconductor device, and a group III-V semiconductor body formed over the second side and comprising at least one group III-V semiconductor device electrically coupled to the at least one group IV semiconductor device. The composite device may further comprise a substrate via and/or a through-wafer via providing electric coupling. In one embodiment, the group IV semiconductor layer may comprise an epitaxial silicon layer, and the at least one group IV semiconductor device may be a combined FET and Schottky diode (FETKY) fabricated on the epitaxial silicon layer. In one embodiment, the at least one group semiconductor device may be a III-nitride high electron mobility transistor (HEMT).

Abstract: Manufacturing circuits with reference plane voids over vias with a strip segment interconnect permits routing critical signal paths over vias, while increasing via insertion capacitance only slightly. The transmission line reference plane defines voids above (or below) signal-bearing plated-through holes (PTHs) that pass through a rigid substrate core, so that the signals are not degraded by an impedance mismatch that would otherwise be caused by shunt capacitance from the top (or bottom) of the signal-bearing PTHs to the transmission line reference plane. In order to provide increased routing density, signal paths are routed over the voids, but disruption of the signal paths by the voids is prevented by including a conductive strip through the voids that reduces the coupling to the signal-bearing PTHs and maintains the impedance of the signal path conductor.

Abstract: A compound semiconductor device includes: a substrate; a first compound semiconductor layer formed over the substrate; a second compound semiconductor layer formed over the first compound semiconductor layer; and an upper electrode formed over the first compound semiconductor layer, wherein two-dimensional hole gas is generated in a region of the first compound semiconductor layer, the region being located at an interface between the first compound semiconductor layer and the second compound semiconductor layer, so as to have a hole concentration that decreases with increasing distance from the upper electrode.

Abstract: A vertical fin structure for a semiconductor transistor includes a semiconductor substrate, a fin layer on top of the substrate, a capping layer overlaying the fin layer, wherein the substrate comprises group IV semiconductor material, the fin layer comprises group IV semiconductor material, the capping layer comprises semiconductor compound from group III-V. The fin layer can comprise Ge, SiGe, SiC, or any combinations thereof. The semiconductor substrate can comprise Si, Ge, SiGe, or SiC. The capping layer can comprise GaAs, InGaAs, InAs, InSb, GaSb, GaN, InP, or any combinations thereof. The capping layer can provide more than a 4 percent lattice mismatch with the semiconductor substrate. The fin layer can be located in between shallow trench insulation (STI) layers that provide isolation from adjacent devices. The vertical fin structure can further include a high-k dielectric layer overlaying the capping layer and a metal gate layer overlaying the high-k dielectric layer.

Abstract: A stacking fault and twin blocking barrier for forming a III-V device layer on a silicon substrate and the method of manufacture is described. Embodiments of the present invention enable III-V InSb device layers with defect densities below 1×108 cm?2 to be formed on silicon substrates. In an embodiment of the present invention, a buffer layer is positioned between a III-V device layer and a silicon substrate to glide dislocations. In an embodiment of the present invention, GaSb buffer layer is selected on the basis of lattice constant, band gap, and melting point to prevent many lattice defects from propagating out of the buffer into the III-V device layer. In a specific embodiment, a III-V InSb device layer is formed directly on the GaSb buffer.

Abstract: According to one disclosed embodiment, a method for fabricating a monolithic integrated composite device comprises forming a group III-V semiconductor body over a group IV semiconductor substrate, forming a trench in the group III-V semiconductor body, and forming a group IV semiconductor body in the trench. The method also comprises fabricating at least one group IV semiconductor device in the group IV semiconductor body, and fabricating at least one group III-V semiconductor device in the group III-V semiconductor body. In one embodiment, the method further comprises planarizing an upper surface of the III-V semiconductor body and an upper surface of the group IV semiconductor body to render those respective upper surfaces substantially co-planar. In one embodiment, the method further comprises fabricating at least one passive device in a defective region of said group IV semiconductor body adjacent to a sidewall of the trench.

Abstract: A device includes providing a silicon substrate; annealing the silicon substrate at a first temperature higher than about 900° C.; and lowering a temperature of the silicon substrate from the first temperature to a second temperature. A temperature lowering rate during the step of lowering the temperature is greater than about 1° C./second. A III-V compound semiconductor region is epitaxially grown on a surface of the silicon substrate using metal organic chemical vapor deposition (MOCVD).

Abstract: A gallium nitride based semiconductor device includes a silicon-based layer doped simultaneously with boron (B) and germanium (Ge) at a relatively high concentration, a buffer layer on the silicon-based layer, and a nitride stack on the buffer layer. A doping concentration of boron (B) and germanium (Ge) may be higher than 1×1019/cm3.

Abstract: Field Effect Transistors (FETs), Integrated Circuit (IC) chips including the FETs, and a method of forming the FETs and IC. FET locations are defined on a layered semiconductor wafer. The layered semiconductor wafer preferably includes a III-V semiconductor surface layer, e.g., Gallium Arsenide (GaAs), and a buried layer, e.g., Aluminum Arsenide (AlAs). Portions of the buried layer are converted to dielectric material, e.g., Aluminum Oxide (AlO), at least beneath FET source/drain regions. The converted dielectric material may extend completely under the FET. Source/drain contacts are formed to FETs above the dielectric material in the buried layer.

Abstract: A direct wafer bonding process for joining GaN and silicon substrates involves pre-treating each of the wafers in an ammonia plasma in order to render the respective contact surfaces ammophilic. The GaN substrate and the silicon substrate may each comprise single crystal wafers. The resulting hybrid semiconductor structure can be used to form high quality, low cost LEDs.

Abstract: A high-frequency device having a switching circuit includes a compound semiconductor substrate; a first high-frequency input/output terminal; a second high-frequency input/output terminal; a control signal input terminal; a power terminal; a ground terminal; an insulating portion disposed on one main surface of the compound semiconductor substrate; and a voltage-applying electrode for applying a predetermined positive voltage from the power electrode to the compound semiconductor substrate, wherein the switching circuit includes a field-effect transistor disposed on the other main surface of the active region of the compound semiconductor substrate.

Abstract: The invention provides semiconductor materials including a gallium nitride material layer formed on a silicon substrate and methods to form the semiconductor materials. The semiconductor materials include a transition layer formed between the silicon substrate and the gallium nitride material layer. The transition layer is compositionally-graded to lower stresses in the gallium nitride material layer which can result from differences in thermal expansion rates between the gallium nitride material and the substrate. The lowering of stresses in the gallium nitride material layer reduces the tendency of cracks to form. Thus, the invention enables the production of semiconductor materials including gallium nitride material layers having few or no cracks. The semiconductor materials may be used in a number of microelectronic and optical applications.

Abstract: A quantum well transistor has a germanium quantum well channel region. A silicon-containing etch stop layer provides easy placement of a gate dielectric close to the channel. A group III-V barrier layer adds strain to the channel. Graded silicon germanium layers above and below the channel region improve performance. Multiple gate dielectric materials allow use of a high-k value gate dielectric.

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: Various techniques for changing the workfunction of the substrate by using a SiGe channel which, in turn, changes the bandgap favorably for a p-type metal oxide semiconductor field effect transistors (pMOSFETs) are disclosed. In the various techniques, a SiGe film that includes a low doped SiGe region above a more highly doped SiGe region to allow the appropriate threshold voltage (Vt) for pMOSFET devices while preventing pitting, roughness and thinning of the SiGe film during subsequent cleans and processing is provided.