Abstract: The present invention relates to a photovoltaic device, especially hybrid solar cells, comprising at least one layer comprising evaporated fluoride and/or acetate; and to a method for preparing the same.

Abstract: A method for increasing the speed of a bipolar transistor, includes the following steps: providing a bipolar transistor having emitter, base, and collector regions; providing electrodes for coupling electrical signals with the emitter, base, and collector regions; and adapting the base region to enhance stimulated emission to the detriment of spontaneous emission, so as to reduce carrier recombination lifetime in the base region.

Abstract: There is provided a light emitting device, which comprises compound semiconductor layers including a first conductive semiconductor layer, an active layer and a second conductive semiconductor layer; a metal reflection layer formed on a region of the second conductive semiconductor layer; an insulating structure formed at least in a boundary region of the second conductive semiconductor layer; a metal material structure formed to cover the second conductive semiconductor layer having the metal reflection layer and the insulating structure formed; and a substrate bonded to the metal material structure, wherein the boundary region of the second conductive semiconductor layer includes an outer region of the second conductive semiconductor layer along an outer circumference of the second conductive semiconductor layer.

Abstract: A field plate portion (5) overhanging a drain side in a visored shape is formed in a gate electrode (2). A multilayered film including a SiN film (21) and a SiO2 film (22) is formed beneath the field plate portion (5). The SiN film (21) is formed so that a surface of an AlGaN electron supply layer (13) is covered therewith.

Abstract: A heterostructure having a heterojunction comprising: a diamond layer; and a boron aluminum nitride (B(x)Al(1-x)N) layer disposed in contact with a surface of the diamond layer, where x is between 0 and 1.

Abstract: A wafer having heterostructure therein is formed using a substrate with recesses formed within a dielectric layer. A magnetized magnetic layer or a polarized electret material is formed at the bottom of each recess. The magnetized magnetic layer or a polarized electret material provides a predetermined magnetic or electrical field pattern. A plurality of heterostructures is formed from on an epitaxial wafer wherein each heterostructure has formed thereon a non-magnetized magnetic layer that is attracted to the magnetized magnetic layer formed at the bottom of each recess or dielectric layer that is attracted to the polarized electret material formed at the bottom of each recess. The plurality of heterostructures is etched from the epitaxial wafer to form a plurality of heterostructure pills.

Abstract: A polishing method for a heterostructure of at least one relaxed superficial heteroepitaxial layer on a substrate made of a different material. The method includes a first chemical mechanical polishing step of the surface of the heteroepitaxial layer performed with a polishing cloth having a first compressibility ratio and with a polishing solution having a first silica particle concentration. The first chemical mechanical polishing step is followed by a second chemical mechanical polishing step of the surface of the heteroepitaxial layer, with the second step being performed with a polishing cloth having a second compressibility ratio, higher than the first compressibility ratio, and with a polishing solution having a second silica particle concentration, lower than the first concentration. By this method, improved surface roughness is achieved.

Abstract: A method for fabricating nitrogen-face (N-face) nitride-based electronic devices with low buffer leakage, comprising isolating a buffer from a substrate with an AlGaInN nucleation layer to suppress impurity incorporation from the substrate into the buffer. A method for fabricating N-face nitride-based electronic devices with low parasitic resistance and high breakdown, comprising capping a device structure with a conductive layer to provide extremely low access and/or contact resistances, is also disclosed.

Abstract: A nitride semiconductor device includes: a substrate containing Si; a channel layer provided on the substrate and made of nitride semiconductor material; a barrier layer provided on the channel layer and made of nitride semiconductor material; a first and second main electrode connected to the barrier layer; and a control electrode provided between the first main electrode and the second main electrode on the barrier layer. The substrate includes at least one layer having a resistivity of 1 k?/cm or more.

Abstract: Provided is a material composition which allows a nonvolatile memory element made of a perovskite-type transition metal oxide having the CER effect to be formed of three elements, which comprises an electric conductor having a shallow work function or a small electronegativity, such as Ti, as an electrode and a rare earth-copper oxide comprising one type of rare earth element, copper and oxygen, such as La2CuO4, as a material constituting a heterojunction with the electric conductor.

Abstract: A method of fabricating AlGaN/GaN enhancement-mode heterostructure field-effect transistors (HFET) using fluorine-based plasma immersion or ion implantation. The method includes: 1) generating gate patterns; 2) exposing the AlGaN/GaN heterostructure in the gate region to fluorine-based plasma treatment with photoresist as the treatment mask in a self-aligned manner; 3) depositing the gate metal to the plasma treated AlGaN/GaN heterostructure surface; 4) lifting off the metal except the gate electrode; and 5) high temperature post-gate annealing of the sample. This method can be used to shift the threshold voltage of a HFET toward a more positive value, and ultimately convert a depletion-mode HFET to an enhancement-mode HFET (E-HFET).

Abstract: The invention relates to a layered structure (1) with semiconducting materials on a support layer (3) comprising at least one planar semiconducting layer (6) and several electrodes, in particular a first (4) and second (5) one. The semiconducting layer (6) has a top (8) and bottom (7) flat face extending essentially parallel and spaced apart from one another by the height of the layer (10). The semiconducting layer (6) is also applied by the bottom flat face (7) to a flat face of the support layer (2) and the two electrodes are connected to the semiconducting layer in an electrically conducting manner The at least two electrodes are applied by means of a structuring process and are disposed on two oppositely lying faces of the semiconducting layer and/or in planes at least approximately parallel between the two faces.

Abstract: A semiconductor device including: a substrate, which has a composition represented by the formula: Ala?Ga1-a?N, wherein a? satisfies 0<a??1; an active layer, which is formed on the substrate, and which has a composition represented by the formula: Alm?Ga1-m?N, wherein m? satisfies 0?m?<1; a buffer layer disposed between the active layer and the substrate; and a first main electrode and a second main electrode, which are formed on the active layer, and which are separated from each other, wherein the semiconductor device is operated by electric current flowing between the first main electrode and the second main electrode in the active layer, and wherein the buffer layer has a composition represented by the formula: AlbIn1-bN, wherein a composition ratio b satisfies 0<b<1, wherein the composition ratio b satisfies m?<b<a?.

Abstract: A metamorphic buffer layer is formed on a semi-insulating substrate by an epitaxial growth method, a collector layer, a base layer, an emitter layer and an emitter cap layer are sequentially laminated on the metamorphic buffer layer, and a collector electrode is provided in contact with an upper layer of the metamorphic buffer layer. The metamorphic buffer layer is doped with an impurity, in a concentration equivalent to or higher than that in a conventional sub-collector layer, by an impurity doping process during crystal growth so that the metamorphic buffer layer will be able to play the role of guiding the collector current to the collector electrode. Since the sub-collector layer, which is often formed of a ternary mixed crystal or the like having a high thermal resistance, can be omitted, the heat generated in the semiconductor device can be rapidly released into the substrate.

Abstract: An integrated circuit structure includes a semiconductor substrate formed of a first semiconductor material; two insulators in the semiconductor substrate; and a semiconductor region between and adjoining sidewalls of the two insulators. The semiconductor region is formed of a second semiconductor material different from the first semiconductor material, and has a width less than about 50 nm.

Abstract: A silicon carbide semiconductor device comprising a region of germanium and a region of crystalline or polycrystalline silicon carbide. The germanium region and the silicon carbide region are configured to form a germanium/silicon carbide heterojunction.

Abstract: The present invention provides a semiconductor device including: a base substrate; a first semiconductor layer disposed on the base substrate; first ohmic electrodes disposed on a central region of the first semiconductor layer; a second ohmic electrode having a ring shape surrounding the first ohmic electrodes, on edge regions of the first semiconductor layer; a second semiconductor layer interposed between the first ohmic electrodes and the first semiconductor layer; and a Schottky electrode part which covers the first ohmic electrodes on the central regions, and is spaced apart from the second ohmic electrode.

Abstract: A nitride semiconductor laser device uses a substrate with low defect density, contains reduced strains inside a nitride semiconductor film, and thus offers a satisfactorily long useful life. On a GaN substrate (10) with a defect density as low as 106 cm?2 or less, a stripe-shaped depressed portion (16) is formed by etching. On this substrate (10), a nitride semiconductor film (11) is grown, and a laser stripe (12) is formed off the area right above the depressed portion (16). With this structure, the laser stripe (12) is free from strains, and the semiconductor laser device offers a long useful life. Moreover, the nitride semiconductor film (11) develops reduced cracks, resulting in a greatly increased yield rate.

Abstract: A nitride semiconductor light-emitting device wherein a substrate or nitride semiconductor layer has a defect concentration region and a low defect density region other than the defect concentration region. A portion including the defect concentration region of the nitride semiconductor layer or substrate has a trench region deeper than the low defect density region. Thus by digging the trench in the defect concentration region, the growth detection is uniformized, and the surface planarity is improved. The uniformity of the characteristic in the wafer surface leads to improvement of the yield.

Abstract: A nitride semiconductor light-emitting device wherein a substrate or nitride semiconductor layer has a defect concentration region and a low defect density region other than the defect concentration region. A portion including the defect concentration region of the nitride semiconductor layer or substrate has a trench region deeper than the low defect density region. Thus by digging the trench in the defect concentration region, the growth detection is uniformized, and the surface planarity is improved. The uniformity of the characteristic in the wafer surface leads to improvement of the yield.

Abstract: A field effect transistor (FET) with high withstand voltage and high performance is realized by designing a buffer layer structure appropriately to reduce a leakage current to 1×10?9 A or less when a low voltage is applied. An epitaxial wafer for a field effect transistor comprising a buffer layer 2, an active layer, and a contact layer on a semi-insulating substrate 1 from the bottom, and the buffer layer 2 includes a plurality of layers, and a p-type buffer layer composed of p-type AlxGa1-xAs (0.3?x?1) is provided as a bottom layer (undermost layer) 2a. A Nd product of a film thickness of the p-type buffer layer and a p-type carrier concentration of the p-type buffer layer is within a range from 1×1010 to 1×1012/cm2.

Abstract: Provided is an epitaxial substrate capable of achieving a semiconductor device that has excellent ohmic contact characteristics as well as satisfactory device characteristics. On a base substrate, a channel layer formed of a first group III nitride that contains at least Al and Ga and has a composition of Inx1Aly1Gaz1N (x1+y1+z1=1) is formed. On the channel layer, a barrier layer formed of a second group III nitride that contains at least In and Al and has a composition of Inx2Aly2Gaz2N (x2+y2+z2=1) is formed such that an In composition ratio of a near-surface portion is larger than an In composition ratio of a portion other than the near-surface portion.

Abstract: The present invention makes available AlxGa(1-x)As (0?x?1) substrates, epitaxial wafers for infrared LEDs, infrared LEDs, methods of manufacturing AlxGa(1-x)As substrates, methods of manufacturing epitaxial wafers for infrared LEDs, and methods of manufacturing infrared LEDs, whereby a high level of transmissivity is maintained, and through which, in the fabrication of semiconductor devices, the devices prove to have superior characteristics. An AlxGa(1-x)As substrate (10a) of the present invention is an AlxGa(1-x)As substrate (10a) furnished with an AlxGa(1-x)As layer (11) having a major surface (11a) and, on the reverse side from the major surface (11a), a rear face (11b), and is characterized in that in the AlxGa(1-x)As layer (11), the amount fraction x of Al in the rear face (11b) is greater than the amount fraction x of Al in the major surface (11a).

Abstract: Planar Schottky diodes for which the semiconductor material includes a heterojunction which induces a 2DEG in at least one of the semiconductor layers. A metal anode contact is on top of the upper semiconductor layer and forms a Schottky contact with that layer. A metal cathode contact is connected to the 2DEG, forming an ohmic contact with the layer containing the 2DEG.

Abstract: In an electronic device of the present invention a gate Schottky electrode is formed on an active layer constructed of a GaN layer and an AlGaN layer, and a source ohmic electrode and a drain ohmic electrode are further formed on both sides of the gate Schottky electrode on the active layer. A dielectric layer (TiO2 layer) of a stepwise laminate structure is formed on the AlGaN layer so that the electric field distribution between the gate Schottky electrode and the drain ohmic electrode is substantially uniformed. The dielectric constant of TiO2 of the dielectric layer is made higher than the dielectric constant of GaN and AlGaN of the active layer.

Abstract: Semiconductor structures and methods of manufacture semiconductors are provided which relate to heterojunction bipolar transistors. The method includes forming 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: Surface modification of individual nitride semiconductor layers occurs between growth stages to enhance the performance of the resulting multiple layer semiconductor structure device formed from multiple growth stages. Surface modifications may include, but are not limited, to laser patterning, lithographic patterning (with the scale ranging from 10 microns to a few angstroms), actinic radiation modifications, implantation, diffusional doping and combinations of these methods. The semiconductor structure device has enhanced crystal quality, reduced phonon reflections, improved light extraction, and an increased emission area. The ability to create these modifications is enabled by the thickness of the HVPE growth of the GaN semiconductor layer.

Abstract: A semiconductor device is provided with: a semiconductor substrate of a predetermined electroconduction type; a hetero semiconductor region contacted with a first main surface of the semiconductor substrate and comprising a semiconductor material having a bandgap different from that of the semiconductor substrate; a gate electrode formed through a gate insulator layer at a position adjacent to a junction region between the hetero semiconductor region and the semiconductor substrate; a source electrode connected to the hetero semiconductor region; and a drain electrode connected to the semiconductor substrate; wherein the hetero semiconductor region includes a contact portion contacted with the source electrode, at least a partial region of the contact portion is of the same electroconduction type as the electroconduction type of the semiconductor substrate, and the partial region has an impurity concentration higher than an impurity concentration of at least that partial region of a gate-electrode facing port

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 can 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: 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 intermediate product in the manufacture of a vertical multiple-channel FET device containing alternating —Si—[(SiGe)—Si]u- stacked layers is shown, as well as a process for selectively etching the SiGe layers in such a stacked layer system, and products obtained from such selective etching. Differential Ge content is added to the successive layers to provide uniform removal of the sacrificial SiGe layers.

Abstract: A laminated film structure, method of manufacturing, and a preferable electronic element using the structure. The effective polarization into the electric field can be realized in the direction of crystal axis by enhancing the crystal property and alignment property of the ferroelectric substance film formed through epitaxial growth with reference to the plane alignment of semiconductor substrate. After the yttrium stabilized zirconium film and a film of the rock salt structure are sequentially formed with epitaxial growth on a semiconductor substrate, the ferroelectric substance film of simple Perovskite structure is also formed with epitaxial growth. The ferroelectric substance film can improve the crystal property and alignment property thereof by rotating the plane for 45 degrees within the plane for the crystal axis of the yttrium stabilized zirconium.

Abstract: In a separation method of a nitride semiconductor layer, a graphene layer in the form of a single layer or two or more layers is formed on a surface of a first substrate. A nitride semiconductor layer is formed on the graphene layer so that the nitride semiconductor layer is bonded to the graphene layer with a bonding force due to regularity of potential at atomic level at an interface therebetween without utilizing covalent bonding. The nitride semiconductor layer is separated from the first substrate with a force which is greater than the bonding force between the nitride semiconductor layer and the graphene layer, or greater than a bonding force between respective layers of the graphene layer.

Abstract: A high quality Group III-Nitride semiconductor crystal with ultra-low dislocation density is grown epitaxially on a substrate via a particle film with multiple vertically-arranged layers of spheres with innumerable micro- and/or nano-voids formed among the spheres. The spheres can be composed of a variety of materials, and in particular silica or silicon dioxide (SiO2).

Abstract: To provide a semiconductor substrate, a semiconductor device, a light emitting device and an electronic device which have a low price, a long lifetime, and a high luminescent efficiency, and moreover are capable of being bent. A graphite substrate having heat resistance and having flexibility with respect to external force, and a first semiconductor layer, provided on the graphite substrate, which is made of a nitride of the Group XIII are included, and a method such as pulse sputter deposition can be used in forming the first semiconductor layer on the graphite substrate, to thereby allow inexpensive manufacture to be possible. In addition, since the nitride of the Group XIII is an inorganic substance, it has a long lifetime, and thus a high luminescent efficiency can be obtained. Moreover, since the graphite substrate has flexibility with respect to external force, it can also be bent.

Abstract: A SiC semiconductor device includes: a SiC substrate having a drain layer, a drift layer and a source layer stacked in this order; multiple trenches penetrating the source layer and reaching the drift layer; a gate layer on a sidewall of each trench; an insulation film on the sidewall of each trench covering the gate layer; a source electrode on the source layer; and a diode portion in or under the trench contacting the drift layer to provide a diode. The drift layer between the gate layer on the sidewalls of adjacent two trenches provides a channel region. The diode portion is coupled with the source electrode, and insulated from the gate layer with the insulation film.

Abstract: Semiconductor wafers having a thin layer of strained semiconductor material. These structures include a substrate; an oxide layer upon the substrate; a silicon carbide (SiC) layer upon the oxide layer, and a strained layer of a semiconductor material in a strained state upon the silicon carbide layer, or a matching layer upon the donor substrate that is made from a material that induces strain in subsequent epitaxially grown layers thereon; a strained layer of a semiconductor material of defined thickness in a strained state; and an insulating or semi-insulating layer upon the strained layer in a thickness that retains the strained state of the strained layer. The insulating or semi-insulating layers are made of silicon carbide or oxides and act to retain strain in the strained layer.

Abstract: The present invention provides a fabrication method of a semiconductor substrate, by which a planar GaN substrate that is easily separated can be fabricated on a heterogeneous substrate, and a semiconductor device which is fabricated using the GaN substrate. The semiconductor substrate comprises a substrate, a first semiconductor layer arranged on the substrate, a metallic material layer arranged on the first semiconductor layer, a second semiconductor layer arranged on the first semiconductor layer and the metallic material layer, and voids formed in the first semiconductor layer under the metallic material layer.

Abstract: A semiconductor device has a Group III nitride semiconductor layer and a gate electrode formed on the Group III nitride semiconductor layer. The gate electrode contains an adhesion enhancing element. A thermally oxidized insulating film is interposed between the Group III nitride semiconductor layer and the gate electrode.

Abstract: A semiconductor device 1 includes a substrate 2 having on a main surface thereof a central area and a peripheral area which surrounds the central area and is exposed, a semiconductor layer 4 which is formed on the main surface of the substrate 2, is made of a material harder than the substrate 2, is in the shape of a mesa, and has a steep side over the exposed peripheral area, and an insulating film 12S provided on a side surface of the semiconductor layer 4.

Abstract: Microelectronic structures and devices, and method of fabricating a three-dimensional microelectronic structure is provided, comprising passing a first precursor material for a selected three-dimensional microelectronic structure into a reaction chamber at temperatures sufficient to maintain said precursor material in a predominantly gaseous state; maintaining said reaction chamber under sufficient pressures to enhance formation of a first portion of said three-dimensional microelectronic structure; applying an electric field between an electrode and said microelectronic structure at a desired point under conditions whereat said first portion of a selected three-dimensional microelectronic structure is formed from said first precursor material; positionally adjusting either said formed three-dimensional microelectronic structure or said electrode whereby further controlled growth of said three-dimensional microelectronic structure occurs; passing a second precursor material for a selected three-dimensional mi

Abstract: A method for producing a solid-state semiconducting structure, includes steps in which: (i) a monocrystalline substrate is provided; (ii) a monocrystalline oxide layer is formed, by epitaxial growth, on the substrate; (iii) a bonding layer is formed by steps in which: (a) the impurities are removed from the surface of the monocrystalline oxide layer; (b) a semiconducting bonding layer is deposited by slow epitaxial growth; and (iv) a monocrystalline semiconducting layer is formed, by epitaxial growth, on the bonding layer so formed. The solid-state semiconducting heterostructures so obtained are also described.

Abstract: A field effect transistor includes a first semiconductor layer made of a multilayer of a plurality of semiconductor films and a second semiconductor layer formed on the first semiconductor layer. A source electrode and a drain electrode are formed on the second semiconductor layer to be spaced from each other. An opening having an insulating film on its inner wall is formed in a portion of the second semiconductor layer sandwiched between the source electrode and the drain electrode so as to expose the first semiconductor layer therein. A gate electrode is formed in the opening to be in contact with the insulating film and the first semiconductor layer on the bottom of the opening.

Abstract: Semiconductor devices having at least one barrier layer are disclosed. In some embodiments, a semiconductor device includes an active layer and one or more barrier layers disposed on either one side or both sides of the active layer. The active layer may be composed of a first compound semiconductor material, and the one or more barrier layers may be composed of a second compound semiconductor material. In some embodiments, the composition of the one or more barrier layers may be adjusted to increase an optical dipole matrix element.

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 can 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 III-nitride heterojunction semiconductor device that includes a power electrode that is electrically connected to a conductive substrate through a trench in the heterojunction thereof.

Abstract: An enhancement mode III-nitride power semiconductor device that includes normally-off channels along the sidewalls of a recess and a process for fabricating the same, the device including a first power electrode, a second power electrode, and a gate disposed between the first power electrode and the second power electrode over at least a sidewall of the recess.

Abstract: The invention relates to a method for forming a semiconductor heterostructure by providing a substrate with a first in-plane lattice parameter a1, providing a buffer layer with a second in-plane lattice parameter a2 and providing a top layer over the buffer layer. In order to improve the surface roughness of the semiconductor heterostructure, an additional layer is provided in between the buffer layer and the top layer, wherein the additional layer has a third in-plane lattice parameter a3 which is in between the first and second lattice parameters.

Abstract: A method for manufacturing heterostructures for applications in the fields of electronics, optics or opto-electronics. This method includes providing a silicon oxide layer with a thickness of less than or equal to 25 nanometers on one of a donor substrate or a receiver substrate or on both substrates, heat treating the substrate(s) that contains the silicon oxide layer at 900° C. to 1,200° C. under a neutral or reducing atmosphere that contains at least one of argon or hydrogen to form layer trapping through-holes inside the silicon oxide, bonding the substrates together at a bonding interface with the silicon oxide layer(s) positioned between them, reinforcing the bonding by annealing the substrates at 25° C. to 500° C. such that the trapping holes retaining gas species at the bonding interface, and transferring an active layer as a portion of the donor substrate onto the receiver substrate to obtain the heterostructure.

Abstract: A system and a process for forming a semi-conductor device, and solar cells (10) formed thereby. The process includes preparing a substrate (12) for deposition of a junction layer (14); forming the junction layer (14) on the substrate (12) using hot wire chemical vapor deposition; and, finishing the semi-conductor device.