Abstract: A method for fabricating edge termination structures in gallium nitride (GaN) materials includes providing an n-type GaN substrate having a first surface and a second surface, forming an n-type GaN epitaxial layer coupled to the first surface of the n-type GaN substrate, and forming one or more p-type regions in the n-type GaN epitaxial layer by using a first ion implantation. At least one of the one or more p-type regions includes an edge termination structure.

Abstract: An MPS diode includes a III-nitride substrate characterized by a first conductivity type and a first dopant concentration and having a first side and a second side. The MPS diode also includes a III-nitride epitaxial structure comprising a first III-nitride epitaxial layer coupled to the first side of the substrate, wherein a region of the first III-nitride epitaxial layer comprises an array of protrusions. The III-nitride epitaxial structure also includes a plurality of III-nitride regions of a second conductivity type, each partially disposed between adjacent protrusions. Each of the plurality of III-nitride regions of the second conductivity type comprises a first section laterally positioned between adjacent protrusions and a second section extending in a direction normal to the first side of the substrate. The MPS diode further includes a first metallic structure electrically coupled to one or more of the protrusions and to one or more of the second sections.

Abstract: A method for fabricating a III-nitride semiconductor device includes providing a III-nitride substrate having a first surface and a second surface opposing the first surface, forming a III-nitride epitaxial layer coupled to the first surface of the III-nitride substrate, and removing at least a portion of the III-nitride epitaxial layer to form a first exposed surface. The method further includes forming a dielectric layer coupled to the first exposed surface, removing at least a portion of the dielectric layer, and forming a metallic layer coupled to a remaining portion of the dielectric layer such that the remaining portion of the dielectric layer is disposed between the III-nitride epitaxial layer and the metallic layer.

Abstract: A method for fabricating a III-nitride semiconductor device includes providing a III-nitride substrate having a first surface and a second surface opposing the first surface, forming a III-nitride epitaxial layer coupled to the first surface of the III-nitride substrate, and removing at least a portion of the III-nitride epitaxial layer to form a first exposed surface. The method further includes forming a dielectric layer coupled to the first exposed surface, removing at least a portion of the dielectric layer, and forming a metallic layer coupled to a remaining portion of the dielectric layer such that the remaining portion of the dielectric layer is disposed between the III-nitride epitaxial layer and the metallic layer.

Abstract: A method for manufacturing a Schottky barrier diode includes the following steps. First, a GaN substrate is prepared. A GaN layer is formed on the GaN substrate. A Schottky electrode including a first layer made of Ni or Ni alloy and in contact with the GaN layer is formed. The step of forming the Schottky electrode includes a step of forming a metal layer to serve as the Schottky electrode and a step of heat treating the metal layer. A region of the GaN layer in contact with the Schottky electrode has a dislocation density of 1×108 cm?2 or less.

Abstract: In a Schottky electrode formation region on a nitride semiconductor, the total length of junctions of Schottky electrodes and a surface of a nitride semiconductor layer is longer than the perimeter of the Schottky electrode formation region. The total length is preferably 10 times longer than the perimeter. For example, the Schottky electrodes are formed concentrically and circularly.

Abstract: Disclosed are structures and methods related to metallization of a doped gallium arsenide (GaAs) layer. In some embodiments, such metallization can include a tantalum nitride (TaN) layer formed on the doped GaAs layer, and a metal layer formed on the TaN layer. Such a combination can yield a Schottky diode having a low turn-on voltage, with the metal layer acting as an anode and an electrical contact connected to the doped GaAs layer acting as a cathode. Such a Schottky diode can be utilized in applications such as radio-frequency (RF) power detection, reference-voltage generation using a clamp diode, and photoelectric conversion. In some embodiments, the low turn-on Schottky diode can be fabricated utilizing heterojunction bipolar transistor (HBT) processes.

Abstract: Disclosed is an improved semiconductor structure (e.g., a silicon germanium (SiGe) hetero-junction bipolar transistor) having a narrow essentially interstitial-free SIC pedestal with minimal overlap of the extrinsic base. Also, disclosed is a method of forming the transistor which uses laser annealing, as opposed to rapid thermal annealing, of the SIC pedestal to produce both a narrow SIC pedestal and an essentially interstitial-free collector. Thus, the resulting SiGe HBT transistor can be produced with narrower base and collector space-charge regions than can be achieved with conventional technology.

Abstract: Disclosed herein is a nitride based semiconductor device. There is provided a nitride based semiconductor device including a base substrate; a semiconductor layer disposed on the base substrate; and an electrode structure disposed on the semiconductor layer, wherein the electrode structure includes: a first electrode ohmic-contacting the semiconductor layer; a ohmic contact unit ohmic-contacting the semiconductor layer and spaced apart from the first electrode; and a schottky contact unit schottky-contacting the semiconductor layer and covering the ohmic contact unit.

Abstract: A method for fabricating a III-nitride semiconductor device includes providing a III-nitride substrate having a first surface and a second surface opposing the first surface, forming a III-nitride epitaxial layer coupled to the first surface of the III-nitride substrate, and removing at least a portion of the III-nitride epitaxial layer to form a first exposed surface. The method further includes forming a dielectric layer coupled to the first exposed surface, removing at least a portion of the dielectric layer, and forming a metallic layer coupled to a remaining portion of the dielectric layer such that the remaining portion of the dielectric layer is disposed between the III-nitride epitaxial layer and the metallic layer.

Abstract: Disclosed herein is a nitride based semiconductor device. There is provided a nitride based semiconductor device including: a base substrate; an epitaxial growth layer disposed on the base substrate and generating 2-dimensional electron gas (2DEG) therein; and an electrode structure disposed on the epitaxial growth layer and having an extension extending into the epitaxial growth layer, wherein the epitaxial growth layer includes a depressing part depressed thereinto from the surface of the epitaxial growth layer, and the depressing part includes: a first area in which the extension is disposed; and a second area that is an area other than the first area.

Abstract: A method for manufacturing a Schottky diode comprising steps of 1) providing a region with a dopant of a second conductivity type opposite to a first conductivity type to form a top doped region in a semiconductor substrate of said first conductivity type; 2) providing a trench through the top doped region to a predetermined depth and providing a dopant of the second conductivity type to form a bottom dopant region of the second conductivity type; and 3) lining a Schottky barrier metal layer on a sidewall of the trench at least extending from a bottom of the top doped region to a top of the bottom doped region.

Abstract: A semiconductor structure includes a III-nitride substrate characterized by a first conductivity type and having a first side and a second side opposing the first side, a III-nitride epitaxial layer of the first conductivity type coupled to the first side of the III-nitride substrate, and a plurality of III-nitride epitaxial structures of a second conductivity type coupled to the III-nitride epitaxial layer. The semiconductor structure further includes a III-nitride epitaxial formation of the first conductivity type coupled to the plurality of III-nitride epitaxial structures, and a metallic structure forming a Schottky contact with the III-nitride epitaxial formation and coupled to at least one of the plurality of III-nitride epitaxial structures.

Abstract: A semiconductor structure includes a III-nitride substrate with a first side and a second side opposing the first side. The III-nitride substrate is characterized by a first conductivity type and a first dopant concentration. The semiconductor structure also includes a III-nitride epitaxial structure including a first III-nitride epitaxial layer coupled to the first side of the III-nitride substrate and a plurality of III-nitride regions of a second conductivity type. The plurality of III-nitride regions have at least one III-nitride epitaxial region of the first conductivity type between each of the plurality of III-nitride regions. The semiconductor structure further includes a first metallic structure electrically coupled to one or more of the plurality of III-nitride regions and the at least one III-nitride epitaxial region. A Schottky contact is created between the first metallic structure and the at least one III-nitride epitaxial region.

Abstract: A monolithic semiconductor structure includes a stack of layers. The stack includes a substrate; a first layer made from a first semiconductor material; and a second layer made from a second semiconductor material. The first layer is situated between the substrate and the second layer and at least one of the first semiconductor material and the second semiconductor material contains a III-nitride material. The structure includes a power transistor, including a body formed in the stack of layers; a first power terminal at a side of the first layer facing the second layer; a second power terminal at least partly formed in the substrate; and a gate structure for controlling the propagation through the body of electric signals between the first power terminal and the second power terminal.

Abstract: In view of achieving a cost reduction of an antenna switch, a technique is provided which can reduce harmonic distortion generated in the antenna switch as much as possible in particular even when the antenna switch is comprised of a field effect transistor formed over a silicon substrate. Each of a TX series transistor, an RX series transistor, and an RX shunt transistor is comprised of a low voltage MISFET, while a TX shunt transistor is comprised of a high voltage MISFET. Thus, by reducing the number of serial connections of the high voltage MISFETs constituting the TX shunt transistor, the nonuniformity of the voltage amplitudes applied to the respective serially-coupled high voltage MISFETs is suppressed. As a result, the generation of high-order harmonics can be suppressed.

Abstract: An IC includes a substrate having a semiconductor top surface, a plurality of metal interconnect levels having inter-level dielectric (ILD) layers therebetween on the top surface, and a bottom surface. A plurality of through substrate vias (TSVs) extend from a TSV terminating metal interconnect level downward to the bottom surface. The plurality of TSVs include an electrically conductive filler material surrounded by a dielectric liner that define a projected volume. The projected volume includes a projected area over the electrically conductive filler material and a projected height extending upwards from the TSV terminating metal interconnect level to a metal interconnect level above, and a projected sidewall surface along sidewalls of the projected volume. A crack suppression structure (CSS) protects TSVs and includes a lateral CSS portion that is positioned lateral to the projected volume and encloses at least 80% of the projected sidewall surface.

Abstract: A III-V-group compound semiconductor device includes a substrate, a channel layer provided over the substrate, a barrier layer provided on the channel layer so as to form a hetero-interface, a plurality of electrodes provided on the barrier layer, an insulator layer provided to cover an entire upper surface of the barrier layer except for at least partial regions of the electrodes, and a hydrogen-absorbing layer stacked on the insulator layer or an integrated layer in which an hydrogen-absorbing layer is integrated with the insulator layer.

Abstract: A silicon carbide semiconductor device with a Schottky barrier diode includes a first conductivity type silicon carbide substrate, a first conductivity type silicon carbide drift layer on a first surface of the substrate, a Schottky electrode forming a Schottky contact with the drift layer, and an ohmic electrode on a second surface of the substrate. The Schottky electrode includes an oxide layer in direct contact with the drift layer. The oxide layer is made of an oxide of molybdenum, titanium, nickel, or an alloy of at least two of these elements.

Abstract: A Schottky gate (27?, 27?) of a metal-semiconductor FET (20?, 20?) is formed on a semiconductor comprising substrate (21) by, etching a gate recess (36) so as to expose a slightly depressed surface (362) of the substrate (21), the etching step also producing surface undercut cavities (363) extending laterally under the etch mask (43) from the gate recess (36), then conformally coating the slightly depressed surface (362) with a first Schottky forming conductor (40?) and substantially also coating inner surfaces (366) of the surface undercut cavities (363), and forming a Schottky contact to the semiconductor comprising substrate (21), adapted when biased to control current flow in a channel (22) extending between source (23) and drain (24) of the FET (20?, 20?) under the gate recess (36).

Abstract: The present invention relates to the field of microelectronic technology. It discloses a mixed Schottky/P-N junction diode and a method of making the same. The mixed Schottky/P-N junction diode comprises a semiconductor substrate having a bulk region and a doped region, and a conductive layer on the semiconductor substrate. The doped region has opposite doping from that of the bulk region. A P-N junction is formed between the bulk region and the doped region, a Schottky junction is formed between the conductive layer and the semiconductor substrate, and an ohmic contact is formed between the conductive layer and the doped region. The mixed Schottky/P-N junction diode of the present invention has high operating current, fast switching speed, small leakage current, high breakdown voltage, ease of fabrication and other advantages.

Abstract: Hybrid semiconductor devices including a PIN diode portion and a Schottky diode portion are provided. The PIN diode portion is provided on a semiconductor substrate and has an anode contact on a first surface of the semiconductor substrate. The Schottky diode portion is also provided on the semiconductor substrate and includes a polysilicon layer on the semiconductor substrate and a ohmic contact on the polysilicon layer. Related Schottky diodes are also provided herein.

Abstract: A group III nitride semiconductor device having a gallium nitride based semiconductor film with an excellent surface morphology is provided. A group III nitride optical semiconductor device 11a includes a group III nitride semiconductor supporting base 13, a GaN based semiconductor region 15, an active layer active layer 17, and a GaN semiconductor region 19. The primary surface 13a of the group III nitride semiconductor supporting base 13 is not any polar plane, and forms a finite angle with a reference plane Sc that is orthogonal to a reference axis Cx extending in the direction of a c-axis of the group III nitride semiconductor. The GaN based semiconductor region 15 is grown on the semipolar primary surface 13a. A GaN based semiconductor layer 21 of the GaN based semiconductor region 15 is, for example, an n-type GaN based semiconductor, and the n-type GaN based semiconductor is doped with silicon.

Abstract: A switching circuit includes a switching device including the first and second main electrodes and a control electrode; and a driver including: a first rectifying device having an anode terminal connected to the first main electrode of the switching device; a first driving device having a first main electrode connected to a cathode terminal of the first rectifying device and a second main electrode connected to the control electrode of the switching device; a second driving device having a first main electrode connected to the control electrode of the switching device and a second main electrode connected to the second main electrode of the switching device; and input terminals receiving control signals inputted to a control electrode of the first driving device and a control electrode of the second driving device.

Abstract: A semiconductor device includes a nitride semiconductor stacked structure including a carrier transit layer and a carrier supply layer; a p-type nitride semiconductor layer provided over the nitride semiconductor stacked structure and including an active region and an inactive region; an n-type nitride semiconductor layer provided on the inactive region in the p-type nitride semiconductor layer; and a gate electrode provided over the active region in the p-type nitride semiconductor layer.

Abstract: In view of achieving a cost reduction of an antenna switch, a technique is provided which can reduce harmonic distortion generated in the antenna switch as much as possible in particular even when the antenna switch is comprised of a field effect transistor formed over a silicon substrate. Each of a TX series transistor, an RX series transistor, and an RX shunt transistor is comprised of a low voltage MISFET, while a TX shunt transistor is comprised of a high voltage MISFET. Thus, by reducing the number of serial connections of the high voltage MISFETs constituting the TX shunt transistor, the nonuniformity of the voltage amplitudes applied to the respective serially-coupled high voltage MISFETs is suppressed. As a result, the generation of high-order harmonics can be suppressed.

Abstract: A wide bandgap semiconductor rectifying device of an embodiment includes a first-conductive-type wide bandgap semiconductor substrate and a first-conductive-type semiconductor layer that has an impurity concentration lower than that of the substrate. The device also includes a first-conductive-type first semiconductor region, and a second-conductive-type second semiconductor region that is formed between the first regions. The device also includes second-conductive-type third semiconductor regions in which at least part of the third regions are connected to the second wide bandgap semiconductor region, the third regions being formed between the first regions, the third regions having a width narrower than that of the second region. The device also includes a first electrode and a second electrode. In the device, a direction in which a longitudinal direction of the third regions are projected onto a (0001) plane of the layer has an angle of 90±30 degrees with respect to a <11-20> direction of the layer.

Abstract: Disclosed herein is a nitride based semiconductor device. There is provided a nitride based semiconductor device including: a base substrate; an epitaxial growth layer disposed on the base substrate and generating 2-dimensional electron gas (2DEG) therein; and an electrode structure disposed on the epitaxial growth layer and having an extension extending into the epitaxial growth layer, wherein the epitaxial growth layer includes a depressing part depressed thereinto from the surface of the epitaxial growth layer, and the depressing part includes: a first area in which the extension is disposed; and a second area that is an area other than the first area.

Abstract: A GaN semiconductor device which has a low on-resistance, has a very small leak current when a reverse bias voltage is applied and is very excellent in withstand voltage characteristic, said GaN semiconductor device having a structure being provided with a III-V nitride semiconductor layer containing at least one hetero junction structure of III-V nitride semiconductors having different band gap energies; a first anode electrode arranged on a surface of said III-V nitride semiconductor by Schottky junction; a second anode electrode which is arranged on the surface of said III-V nitride semiconductor layer by Schottky junction, is electrically connected with said first anode electrode and forms a higher Schottky barrier than a Schottky barrier formed by said first anode electrode; and an insulating protection film which is brought into contact with said second anode electrode and is arranged on the surface of said III-V nitride semiconductor layer.

Abstract: An intermediate metal film is formed between a Schottky electrode and a pad electrode. A Schottky barrier height between the intermediate metal film and a silicon carbide epitaxial film is equivalent to or higher than a Schottky barrier height between the Schottky electrode and the silicon carbide epitaxial film. By this configuration, an excess current and a leak current through a pin-hole can be suppressed even in the case in which a Schottky barrier height between the pad electrode and the silicon carbide epitaxial film is less than the Schottky barrier height between the Schottky electrode and the silicon carbide epitaxial film.

Abstract: Hardmask films having high hardness and low stress are provided. In some embodiments a film has a stress of between about ?600 MPa and 600 MPa and hardness of at least about 12 GPa. In some embodiments, a hardmask film is prepared by depositing multiple sub-layers of doped or undoped silicon carbide using multiple densifying plasma post-treatments in a PECVD process chamber. In some embodiments, a hardmask film includes a high-hardness boron-containing film selected from the group consisting of SixByCz, SixByNz, SixByCzNw, BxCy, and BxNy. In some embodiments, a hardmask film includes a germanium-rich GeNx material comprising at least about 60 atomic % of germanium. These hardmasks can be used in a number of back-end and front-end processing schemes in integrated circuit fabrication.

Abstract: A III-nitride device includes a recessed electrode to produce a nominally off, or an enhancement mode, device. By providing a recessed electrode, a conduction channel formed at the interface of two III-nitride materials is interrupted when the electrode contact is inactive to prevent current flow in the device. The electrode can be a schottky contact or an insulated metal contact. Two ohmic contacts can be provided to form a rectifier device with nominally off characteristics. The recesses formed with the electrode can have sloped sides. The electrode can be formed in a number of geometries in conjunction with current carrying electrodes of the device. A nominally on device, or pinch resistor, is formed when the electrode is not recessed. A diode is also formed by providing non-recessed ohmic and schottky contacts through an insulator to an AlGaN layer.

Abstract: Improved Schottky diodes with reduced leakage current and improved breakdown voltage are provided by building a JFET with its current path of a first conductivity type serially located between a first terminal comprising a Schottky contact and a second terminal. The current path lies (i) between multiple substantially parallel finger regions of a second, opposite, conductivity type substantially laterally outboard of the Schottky contact, and (ii) partly above a buried region of the second conductivity type that underlies a portion of the current path, which regions are electrically coupled to the first terminal and the Schottky contact and which portion is electrically coupled to the second terminal. When reverse bias is applied to the first terminal and Schottky contact, the current path is substantially pinched off in vertical or horizontal directions or both, thereby reducing the leakage current and improving the breakdown voltage of the device.

Abstract: A device according to the invention comprises a Schottky barrier formed by a metal-semiconductor junction between a semiconductor nanowire (1) and a metal contact (5). The metal contact (5) at least partly encloses a circumferential area of each nanowire (1) along the length thereof. The nanowire (2) comprises a lowly doped region that is part of the metal-semiconductor junction. This lowly doped region can be formed by a nanowire segment, by the entire nanowire or in a core-shell configuration with a highly doped nanowire core (3) and the lowly doped region comprised in a shell (4). The device can be fabricated using a method according to the invention, where two different growth modes are used, the first comprising axial growth from a substrate (2) giving a suitable template for formation of the metal-semiconductor junction and the second step comprising radial growth enabling control of the doping levels in the lowly doped region.

Abstract: This invention discloses bottom-anode Schottky (BAS) device supported on a semiconductor substrate having a bottom surface functioning as an anode electrode with an epitaxial layer has a same doped conductivity as said anode electrode overlying the anode electrode. The BAS device further includes an Schottky contact metal disposed in a plurality of trenches and covering a top surface of the semiconductor substrate between the trenches. The BAS device further includes a plurality of doped JBS regions disposed on sidewalls and below a bottom surface of the trenches doped with an opposite conductivity type from the anode electrode constituting a junction barrier Schottky (JBS) with the epitaxial layer disposed between the plurality of doped JBS regions. The BAS device further includes an ultra-shallow Shannon implant layer disposed immediate below the Schottky contact metal in the epitaxial layer between the plurality of doped JBS regions.

Abstract: [Problem to be Solved] Provided is a semiconductor device in which the trade-off between the pressure resistance and the on-state resistance is improved and the performance is improved.

Abstract: A III-nitride device includes a recessed electrode to produce a nominally off, or an enhancement mode, device. By providing a recessed electrode, a conduction channel formed at the interface of two III-nitride materials is interrupted when the electrode contact is inactive to prevent current flow in the device. The electrode can be a schottky contact or an insulated metal contact. Two ohmic contacts can be provided to form a rectifier device with nominally off characteristics. The recesses formed with the electrode can have sloped sides. The electrode can be formed in a number of geometries in conjunction with current carrying electrodes of the device. A nominally on device, or pinch resistor, is formed when the electrode is not recessed. A diode is also formed by providing non-recessed ohmic and schottky contacts through an insulator to an AlGaN layer.

Abstract: The present invention relates a method for forming a monocrystalline GeN layer (4) on a substrate (1) comprising at least a Ge surface (3). The method comprises, while heating the substrate (1) to a temperature between 550° C. and 940° C., exposing the substrate (1) to a nitrogen gas flow. The present invention furthermore provides a structure comprising a monocrystalline GeN layer (4) on a substrate (1). The monocrystalline GeN formed by the method according to embodiments of the invention allows passivation of surface states present at the Ge surface (3).

Abstract: A GaN heterojunction FET has an AlxGa1-xN first graded layer and an AlyGa1-yN second graded layer, which are formed sequentially on a channel layer. The Al mole fraction x of the first graded layer decreases linearly from, for example, 0.2 at an interface of the first graded layer with the channel layer to 0.1 at an interface thereof with the second graded layer. The Al mole fraction y of the second graded layer increases from, for example, 0.1 at an interface of the second graded layer with the first graded layer to 0.35 at a surface located on the opposite side from the first graded layer. Because the intrinsic polarization of AlGaN depends on the Al mole fraction, fixed negative charge is generated in the AlxGa1-xN first graded layer, and fixed positive charge is generated in the AlyGa1-yN second graded layer.

Abstract: A semiconductor device provided with a silicon carbide semiconductor substrate, and an ohmic metal layer joined to one surface of the silicon carbide semiconductor substrate in an ohmic contact and composed of a metal material whose silicide formation free energy and carbide formation free energy respectively take negative values. The ohmic metal layer is composed of, for example, a metal material such as molybdenum, titanium, chromium, manganese, zirconium, tantalum, or tungsten.

Abstract: The structure for millimeter-wave frequency applications, includes a Schottky barrier diode (SBD) with a cutoff frequency (FC) above 1.0 THz formed on a SiGe BiCMOS wafer. A method is also contemplated for forming a Schottky barrier diode on a SiGe BiCMOS wafer, including forming a structure which provides a cutoff frequency (Fc) above about 1.0 THz. In embodiments, the structure which provides a cutoff frequency (Fc) above about 1.0 THz may include an anode having an anode area which provides a cutoff frequency (FC) above about 1.0 THz, an n-epitaxial layer having a thickness which provides a cutoff frequency (FC) above about 1.0 THz, a p-type guardring at an energy and dosage which provides a cutoff frequency (FC) above about 1.0 THz, the p-type guardring having a dimension which provides a cutoff frequency (FC) above about 1.0 THz, and a well tailor with an n-type dopant which provides a cutoff frequency (FC) above about 1.0 THz.

Abstract: The present invention relates a method for forming a monocrystalline GeN layer (4) on a substrate (1) comprising at least a Ge surface (3). The method comprises, while heating the substrate (1) to a temperature between 550° C. and 940° C., exposing the substrate (1) to a nitrogen gas flow. The present invention furthermore provides a structure comprising a monocrystalline GeN layer (4) on a substrate (1). The monocrystalline GeN formed by the method according to embodiments of the invention allows passivation of surface states present at the Ge surface (3).

Abstract: A silicon carbide semiconductor device includes a substrate; a drift layer having a first conductivity type; an insulating layer; a Schottky electrode; an ohmic electrode; a resurf layer; and second conductivity type layers. The drift layer and the second conductivity type layers provide multiple PN diodes. Each second conductivity type layer has a radial width with respect to a center of a contact region between the Schottky electrode and the drift layer. A radial width of one of the second conductivity type layers is smaller than that of another one of the second conductivity type layers, which is disposed closer to the center of the contact region than the one of the second conductivity type layers.

Abstract: A silicon carbide semiconductor device includes a drift layer having first conductive type on a substrate, a cell region in the drift layer, a schottky electrode on the drift layer and multiple second conductive type layers in the cell region. The second conductive type layers are separated from each other and contact the schottky electrode. A size and an impurity concentration of the second conductive type layers and a size and an impurity concentration of a portion of the drift layer sandwiched between the second conductive type layers are determined so that a charge quantity of the second conductive type layers is equal to a charge quantity of the portion. Hereby, the pressure-proof JBS and low resistivity second conductive type layers arranged on a surface of the drift layer to provide a PN diode, can be obtained.

Abstract: A gallium nitride based semiconductor diode includes a substrate, a GaN layer formed on the substrate, an AlGaN layer formed on the GaN layer where the GaN layer and the AlGaN layer forms a cathode region of the diode, a metal layer formed on the AlGaN layer forming a Schottky junction therewith where the metal layer forms an anode electrode of the diode, and a high barrier region formed in the top surface of the AlGaN layer and positioned under an edge of the metal layer. The high barrier region has a higher bandgap energy than the AlGaN layer or being more resistive than the AlGaN layer.

Abstract: A junction barrier Schottky diode has an N-type well having surface and a first impurity concentration; a p-type anode region in the surface of the well, and having a second impurity concentration; and an N-type cathode region in the surface of the well and horizontally abutting the anode region, and having a third impurity concentration. A first N-type region vertically abuts the anode and cathode regions, and has a fourth impurity concentration. An ohmic contact is made to the anode and a Schottky contact is made to the cathode. The fourth impurity concentration is less than the first, second and third impurity concentrations.

Abstract: A semiconductor device includes a first semiconductor layer which is formed above a substrate, a Schottky electrode and an ohmic electrode which are formed on the first semiconductor layer to be spaced from each other and a second semiconductor layer which is formed to cover the first semiconductor layer with the Schottky electrode and the ohmic electrode exposed. The second semiconductor layer has a larger band gap than that of the first semiconductor layer.

Abstract: An electronic device made of group III/N materials and a method of fabricating the device. The method includes growing by epitaxy on a substrate layer the following successive layers: a layer adapted to contain an electron gas, a barrier layer, and a surface layer. The method also includes an etching step performed on at least part of the surface layer. After the etching step, an epitaxial regrowth is performed to grow a covering layer on the etched surface layer. The material of the surface layer and the material of the covering layer include at least one Group III element and nitrogen.

Abstract: A Schottky gate (27?, 27?) of a metal-semiconductor FET (20?, 20?) is formed on a semiconductor comprising substrate (21) by, etching a gate recess (36) so as to expose a slightly depressed surface (362) of the substrate (21), the etching step also producing surface undercut cavities (363) extending laterally under the etch mask (43) from the gate recess (36), then conformally coating the slightly depressed surface (362) with a first Schottky forming conductor (40?) and substantially also coating inner surfaces (366) of the surface undercut cavities (363), and forming a Schottky contact to the semiconductor comprising substrate (21), adapted when biased to control current flow in a channel (22) extending between source (23) and drain (24) of the FET (20?, 20?) under the gate recess (36).

Abstract: To provide a semiconductor device that has a sufficiently low on-resistance and excellent low-capacitance and high-speed characteristics as compared with conventional GaN-based diodes. The semiconductor device includes: a substrate (101); a buffer layer (102); a stack structure (103 and 104) including at least one heterojunction unit (103 and 104) that is a stack of a layer (GaN layer 103) made of a nitride semiconductor and a layer (AlGaN layer 104) made of another nitride semiconductor having a larger band gap than the nitride semiconductor (GaN layer 103); a Schottky electrode (106) that is placed at a first end of the stack structure (103 and 104) and forms a Schottky barrier contact with the heterojunction unit (103 and 104); and an ohmic electrode (107) that is placed at a second end of the stack structure (103 and 104) and forms an ohmic contact with the heterojunction unit (103 and 104).