Abstract: A transistor is disclosed. The transistor includes a substrate, a superlattice structure that includes a plurality of heterojunction channels, and a gate that extends to one of the plurality of heterojunction channels. The transistor also includes a source adjacent a first side of the superlattice structure and a drain adjacent a second side of the superlattice structure.

Abstract: Provided are a semiconductor substrate and a transistor. The semiconductor substrate includes a base, an insulating layer, a semiconductor layer, a wide bandgap diffusion buffer layer and a nucleation layer. The insulating layer is disposed on the base. The semiconductor layer is disposed on the insulating layer. The wide bandgap diffusion buffer layer is disposed on the semiconductor layer, wherein the bandgap of the wide bandgap buffer diffusion layer is higher than 2.5 eV. The nucleation layer is disposed on the wide bandgap diffusion buffer layer, wherein the nucleation layer includes an aluminum-containing layer.

Abstract: A semiconductor device includes a doped substrate and a seed layer in direct contact with the substrate. The seed layer includes a first seed sublayer having a first lattice structure. The first seed layer is doped with carbon. The seed layer further includes a second seed sublayer over the first see layer, wherein the second seed layer has a second lattice structure. The semiconductor device further includes a graded layer in direct contact with the seed layer. The graded layer includes a first graded sublayer including AlGaN having a first Al:Ga ratio; a second graded sublayer including AlGaN having a second Al:Ga ratio different from the first Al:Ga ratio; and a third graded sublayer over including AlGaN having a third Al:Ga ratio different from the second Al:Ga ratio. The semiconductor device includes a channel layer over the graded layer. The semiconductor device includes an active layer over the channel layer.

Abstract: A semiconductor device and a method of making the same. The device includes a substrate having an AlGaN layer located on one or more GaN layers, for forming a two dimensional electron gas at an interface between the AlGaN layer and the GaN layer. The device also includes a source contact. The device further includes a drain contact. The device also includes a gate contact located between the source contact and the drain contact. The gate contact includes a gate electrode. The gate contact also includes an electrically insulating layer located between the gate electrode and the AlGaN layer. The insulating layer includes at least one aperture for allowing holes generated during an off-state of the device to exit the device through the gate electrode.

Abstract: An electrode structure, a GaN-based semiconductor device including the electrode structure, and methods of manufacturing the same, may include a GaN-based semiconductor layer and an electrode structure on the GaN-based semiconductor layer. The electrode structure may include an electrode element including a conductive material and a diffusion layer between the electrode element and the GaN-based semiconductor layer. The diffusion layer may include a material which is an n-type dopant with respect to the GaN-based semiconductor layer, and the diffusion layer may contact the GaN-based semiconductor layer. A region of the GaN-based semiconductor layer contacting the diffusion layer may be doped with the n-type dopant. The material of the diffusion layer may comprise a Group 4 element.

Abstract: A field-effect transistor includes a carrier transport layer made of nitride semiconductor, a gate electrode having first and second sidewall surfaces on first and second sides, respectively, an insulating film formed directly on the gate electrode to cover at least one of the first and second sidewall surfaces, first and second ohmic electrodes formed on the first and second sides, respectively, a passivation film including a first portion extending from the first ohmic electrode toward the gate electrode to cover a surface area between the first ohmic electrode and the gate electrode and a second portion extending from the second ohmic electrode toward the gate electrode to cover a surface area between the second ohmic electrode and the gate electrode, wherein the insulating film is in direct contact with at least the first and second passivation film portions, and has a composition different from that of the passivation film.

Abstract: A method for fabricating a semiconductor device is disclosed. The method includes sequentially forming a first semiconductor layer, a second semiconductor layer and a semiconductor cap layer containing a p-type impurity element on a substrate, forming a dielectric layer having an opening after the forming of the semiconductor cap layer, forming a third semiconductor layer containing a p-type impurity element on the semiconductor cap layer exposed from the opening of the dielectric layer, and forming a gate electrode on the third semiconductor layer.

Abstract: A III-nitride transistor includes a III-nitride channel layer, a barrier layer over the channel layer, the barrier layer having a thickness of 1 to 10 nanometers, a dielectric layer on top of the barrier layer, a source electrode contacting the channel layer, a drain electrode contacting the channel layer, a gate trench extending through the dielectric layer and barrier layer and having a bottom located within the channel layer, a gate insulator lining the gate trench and extending over the dielectric layer, and a gate electrode in the gate trench and extending partially toward the source and the drain electrodes to form an integrated gate field-plate, wherein a distance between an interface of the channel layer and the barrier layer and the bottom of the gate trench is greater than 0 nm and less than or equal to 5 nm.

Abstract: In accordance with one or more embodiments, an apparatus and method involves a channel region, barrier layers separated by the channel region and a dielectric on one of the barrier layers. The barrier layers have band gaps that are different than a band gap of the channel region, and confine both electrons and holes in the channel region. A gate electrode applies electric field to the channel region via the dielectric. In various contexts, the apparatus and method are amenable to implementation for both electron-based and hole-based implementations, such as for nmos, pmos, and cmos applications.

Abstract: A device includes a source and a drain for transmitting and receiving an electronic charge. The device also includes a first stack and a second stack for providing at least part of a conduction path between the source and the drain, wherein the first stack includes a first gallium nitride (GaN) layer of a first polarity, and the second stack includes a second gallium nitride (GaN) layer of the second polarity, and wherein the first polarity is different from the second polarity. At least one gate operatively connected to at least the first stack for controlling a conduction of the electronic charge, such that, during an operation of the device, the conduction path includes a first two-dimensional electron gas (2DEG) channel formed in the first GaN layer and a second 2DEG channel formed in the second GaN layer.

Abstract: A III-N device is described with a III-N layer, an electrode thereon, a passivation layer adjacent the III-N layer and electrode, a thick insulating layer adjacent the passivation layer and electrode, a high thermal conductivity carrier capable of transferring substantial heat away from the III-N device, and a bonding layer between the thick insulating layer and the carrier. The bonding layer attaches the thick insulating layer to the carrier. The thick insulating layer can have a precisely controlled thickness and be thermally conductive.

Abstract: A nitride semiconductor device includes a first semiconductor layer, a second semiconductor layer, a conductive substrate, a first electrode, a second electrode, and a control electrode. The second semiconductor layer is directly bonded to the first semiconductor layer. The conductive substrate is provided on and electrically connected to the first semiconductor layer. The first electrode and the second electrode are provided on and electrically connected to a surface of the second semiconductor layer on a side opposite to the first semiconductor layer. The control electrode is provided on the surface of the second semiconductor layer between the first electrode and the second electrode. The first electrode is electrically connected to a drain electrode of a MOSFET formed of Si. The control electrode is electrically connected to a source electrode of the MOSFET. The conductive substrate is electrically connected to a gate electrode of the MOSFET.

Abstract: A semiconductor structure includes a first III-V compound layer. A second III-V compound layer is disposed on the first III-V compound layer and different from the first III-V compound layer in composition. A carrier channel is located between the first III-V compound layer and the second III-V compound layer. A source feature and a drain feature are disposed on the second III-V compound layer. A gate electrode is disposed over the second III-V compound layer between the source feature and the drain feature. Two slanted field plates are disposed on the two side walls of the combined opening of the opening in a protection layer and the opening in a dielectric cap layer disposed on the second III-V compound layer.

Abstract: A III-nitride device is provided comprising a semiconductor substrate; a stack of active layers on the substrate, each layer comprising a III-nitride material; a gate, a source and a drain contact on the stack, wherein a gate, a source and a drain region of the substrate are projections of respectively the gate, the source and the drain contact in the substrate; and a trench in the substrate extending from a backside of the substrate (side opposite to the one in contact with the stack of active layers) to an underlayer of the stack of active layers in contact with the substrate, the trench completely surrounding the drain region, being positioned in between an edge of the gate region towards the drain and an edge of the drain region towards the gate and having a width such that the drain region of the substrate is substantially made of the semiconductor material.

Abstract: A high voltage durability III-nitride semiconductor device comprises a support substrate including a first silicon body, an insulator body over the first silicon body, and a second silicon body over the insulator body. The high voltage durability III-nitride semiconductor device further comprises a III-nitride semiconductor body characterized by a majority charge carrier conductivity type, formed over the second silicon body. The second silicon body has a conductivity type opposite the majority charge carrier conductivity type. In one embodiment, the high voltage durability III-nitride semiconductor device is a high electron mobility transistor (HEMT) comprising a support substrate including a <100> silicon layer, an insulator layer over the <100> silicon layer, and a P type conductivity <111> silicon layer over the insulator layer.

Abstract: The present invention reduces the dynamic on resistance in the channel layer of a GaN device by etching a void in the nucleation and buffer layers between the gate and the drain. This void and the underside of the device substrate may be plated to form a back gate metal layer. The present invention increases the device breakdown voltage by reducing the electric field strength from the gate to the drain of a HEMT. This electric field strength is reduced by placing a back gate metal layer below the active region of the channel. The back gate metal layer may be in electrical contact with the source or drain.

Abstract: The invention relates to a new High Electron Mobility Transistor (HEMT), made essentially of layers of Group XIII element(s) nitride(s). Contrary to currently available transistors of this type, the transistor according to the invention is produced on a homosubstrate made of gallium-containing nitride, has no nucleation layer and its buffer layer is remarkably thinner than in known HEMTs. Preferably, at least the buffer layer, being a part of the transistor according to the present invention, is produced by epitaxial methods and the direction of growth of said layer in an epitaxial process is essentially perpendicular to the direction of growth of the substrate. The invention relates also to a method of manufacturing of High Electron Mobility Transistor (HEMT).

Abstract: The present invention relates to fabrication of enhancement mode and depletion mode High Electron Mobility Field Effect Transistors on the same die separated by as little as 10 nm. The fabrication method uses selective decomposition and selective regrowth of the Barrier layer and the Cap layer to engineer the bandgap of a region on a die to form an enhancement mode region. In these regions zero or more devices may be fabricated.

Abstract: A semiconductor structure includes a first III-V compound layer. A second III-V compound layer is disposed on the first III-V compound layer and is different from the first III-V compound layer in composition. A source feature and a drain feature are disposed on the second III-V compound layer. A gate electrode is disposed over the second III-V compound layer between the source feature and the drain feature. A fluorine region is embedded in the second III-V compound layer under the gate electrode. A gate dielectric layer is disposed over the second III-V compound layer. The gate dielectric layer has a fluorine segment on the fluorine region and under at least a portion of the gate electrode.

Abstract: A III-nitride power semiconductor device that includes a plurality of III-nitride heterojunctions.

Abstract: A semiconductor structure is disclosed. The semiconductor structure includes a first layer. A second layer is disposed on the first layer and different from the first layer in composition. An interface is between the first layer and the second layer. A third layer is disposed on the second layer. A gate is disposed on the third layer. A source feature and a drain feature are disposed on opposite sides of the gate. Each of the source feature and the drain feature includes a corresponding metal feature at least partially embedded in the second and the third layer. A corresponding intermetallic compound underlies each metal feature. Each intermetallic compound contacts a carrier channel located at the interface.

Abstract: The present invention provides a semiconductor device having such a structure formed by sequentially laminating a lower barrier layer composed of lattice-relaxed AlxGa1-xN (0?x?1), a channel layer composed of InyGa1-yN (0?y?1) with compressive strain and a contact layer composed of AlzGa1-zN (0?z?1), wherein a two-dimensional electron gas is produced in the vicinity of an interface of said InyGa1-yN channel layer with said AlzGa1-zN contact layer; a gate electrode is formed so as to be embedded in the recessed portion with intervention of an insulating film, which recessed portion is formed by removing a part of said AlzGa1-zN contact layer by etching it away until said InyGa1-yN channel layer is exposed; and, ohmic electrodes are formed on the AlzGa1-zN contact layer. Thus, the semiconductor device has superior uniformity and reproducibility of the threshold voltage while maintaining a low gate leakage current, and is also applicable to the enhancement mode type.

Abstract: A field effect transistor (FET) includes source and drain electrodes, a channel layer, a barrier layer over the channel layer, a passivation layer covering the barrier layer for passivating the barrier layer, a gate electrode extending through the barrier layer and the passivation layer, and a gate dielectric surrounding a portion of the gate electrode that extends through the barrier layer and the passivation layer, wherein the passivation layer is a first material and the gate dielectric is a second material, and the first material is different than the second material.

Abstract: A III-nitride semiconductor electronic device comprises a semiconductor laminate provided on a primary surface of a substrate, a first electrode in contact with the semiconductor laminate, and a second electrode. The semiconductor laminate includes a channel layer and a barrier layer making a junction with the channel layer. The channel layer comprises first III-nitride semiconductor containing aluminum as a Group III constituent element, and the barrier layer comprises second III-nitride semiconductor containing aluminum as a Group III constituent element. The semiconductor laminate including first, second and third regions arranged along the primary surface, and the third region is located between the first region and the second region. The barrier layer includes first to third portions included in the first to third regions, respectively.

Abstract: A III-N device is described with a III-N layer, an electrode thereon, a passivation layer adjacent the III-N layer and electrode, a thick insulating layer adjacent the passivation layer and electrode, a high thermal conductivity carrier capable of transferring substantial heat away from the III-N device, and a bonding layer between the thick insulating layer and the carrier. The bonding layer attaches the thick insulating layer to the carrier. The thick insulating layer can have a precisely controlled thickness and be thermally conductive.

Abstract: Enhancement mode III-nitride devices are described. The 2DEG is depleted in the gate region so that the device is unable to conduct current when no bias is applied at the gate. Both gallium face and nitride face devices formed as enhancement mode devices.

Abstract: Techniques for employing different channel materials within the same CMOS circuit are provided. In one aspect, a method of fabricating a CMOS circuit includes the following steps. A wafer is provided having a first semiconductor layer on an insulator. STI is used to divide the first semiconductor layer into a first active region and a second active region. The first semiconductor layer is recessed in the first active region. A second semiconductor layer is epitaxially grown on the first semiconductor layer, wherein the second semiconductor layer comprises a material having at least one group III element and at least one group V element. An n-FET is formed in the first active region using the second semiconductor layer as a channel material for the n-FET. A p-FET is formed in the second active region using the first semiconductor layer as a channel material for the p-FET.

Abstract: A transistor includes a first semiconductor layer formed on a substrate, a second semiconductor layer formed on the first semiconductor layer and has a band gap larger than that of the first semiconductor layer, a control layer formed on the second semiconductor layer and contains p-type impurities, a gate electrode formed in contact with at least part of the control layer and a source electrode and a drain electrode formed on both sides of the control layer, respectively. A third semiconductor layer made of material having a lower etch rate than that of the control layer is formed between the control layer and the second semiconductor layer.

Abstract: An embodiment of a compound semiconductor device includes: a substrate; an electron channel layer and an electron supply layer formed over the substrate; a gate electrode, a source electrode and a drain electrode formed on or above the electron supply layer; and a p-type semiconductor layer formed between the electron supply layer and the gate electrode. The p-type semiconductor layer contains, as a p-type impurity, an element same as that being contained in at least either of the electron channel layer and the electron supply layer.

Abstract: To suppress adverse affect caused by dopant in a conductive semiconductor layer in a GaN-based device having a structure in which the conductive semiconductor layer is inserted between a substrate and an active layer. In an HEMT device 10, n-GaN (n-type GaN wafer) is used as a substrate 11. A p-type GaN layer (conductive semiconductor layer) 12 is formed on the substrate 11 for the purpose of reducing a leak current and suppressing current collapse, etc. A non-doped AlN layer (semi-insulating semiconductor layer) 13 is formed on the p-type GaN layer 12, and a channel layer (active layer) 14 formed of semi-insulating GaN and an electron supply layer (active layer) 15 formed of n-AlGaN are sequentially formed by the MBE method, MOVPE method, or the like.

Abstract: Some exemplary embodiments of high voltage cascoded III-nitride semiconductor package utilizing clips on a package support surface have been disclosed. One exemplary embodiment comprises a III-nitride transistor attached to a package support surface and having an anode of a diode stacked over a source of the III-nitride transistor, a first conductive clip coupled to a gate of the III-nitride transistor and the anode of the diode, and a second conductive clip coupled to a drain of the III-nitride transistor. The conductive clips are connected to the package support surface and expose respective flat portions that are surface mountable. In this manner, reduced package footprint, improved surge current capability, and higher performance may be achieved compared to conventional wire bonded packages. Furthermore, since a low cost printed circuit board (PCB) may be utilized for the package support surface, expensive leadless fabrication processes may be avoided for cost effective manufacturing.

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

Abstract: A field effect transistor having a channel, a gate, and a structure for decreasing a gate-to-channel capacitance of the transistor as an operating frequency of the transistor increases. The structure can comprise, for example, a barrier disposed between the gate and the channel, which has a dielectric permittivity and/or a conductivity that varies with an operating frequency of the transistor. In an embodiment, the barrier comprises a layer of conducting material, such as conducting polymer, conducting semiconductor, conducting semi-metal, amorphous silicon, polycrystalline silicon, and/or the like.

Abstract: The invention relates to a semiconductor device, in particular to a chemical field effect transistor (ChemFET), a high-electron mobility transistor (HEMT) and an ion-sensitive field effect transistor (ISFET), as well as a method for manufacturing the same. The semiconductor device comprises a structure, the structure comprises a substrate, a first layer comprising GaN and a second layer comprising InAlN, wherein the first and the second layer are arranged parallely to each other on the substrate, and wherein the structure comprises a third layer comprising diamond.

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 semiconductor device including a first GaN layer, an AlGaN layer, a second GaN layer, a gate electrode, a source electrode, and a drain electrode sequentially stacked on a substrate, capable of improving a leakage current and a breakdown voltage characteristics generated in the gate electrode by locally forming a p type GaN layer on the AlGaN layer, and a manufacturing method thereof, and a manufacturing method thereof are provided. The semiconductor device includes: a substrate, a first GaN layer formed on the substrate, an AlGaN layer formed on the first GaN layer, a second GaN layer formed on the AlGaN layer and including a p type GaN layer, and a gate electrode formed on the second GaN layer, wherein the p type GaN layer may be in contact with a portion of the gate electrode.

Abstract: An AlN layer (2), a GaN buffer layer (3), a non-doped AlGaN layer (4a), an n-type AlGaN layer (4b), an n-type GaN layer (5), a non-doped AlN layer (6) and an SiN layer (7) are sequentially formed on an SiC substrate (1). At least three openings are formed in the non-doped AlN layer (6) and the SiN layer (7), and a source electrode (8a), a drain electrode (8b) and a gate electrode (19) are evaporated in these openings.

Abstract: The present invention has an object to provide an FET and a method of manufacturing the FET that are capable of increasing the threshold voltage as well as decreasing the on-resistance. The FET of the present invention includes a first undoped GaN layer; a first undoped AlGaN layer formed on the first undoped GaN layer, having a band gap energy greater than that of the first undoped GaN layer; a second undoped GaN layer formed on the first undoped AlGaN layer; a second undoped AlGaN layer formed on the second undoped GaN layer, having a band gap energy greater than that of the second undoped GaN layer; a p-type GaN layer formed in the recess of the second undoped AlGaN layer; a gate electrode formed on the p-type GaN layer; and a source electrode and a drain electrode which are formed in both lateral regions of the gate electrode, wherein a channel is formed at the heterojunction interface between the first undoped GaN layer and the first undoped AlGaN layer.

Abstract: A III-nitride power semiconductor device that includes a plurality of III-nitride heterojunctions.

Abstract: A semiconductor wafer includes a base wafer, a first semiconductor portion that is formed on the base wafer and includes a first channel layer containing a majority carrier of a first conductivity type, a separation layer that is formed over the first semiconductor portion and contains an impurity to create an impurity level deeper than the impurity level of the first semiconductor portion, and a second semiconductor portion that is formed over the separation layer and includes a second channel layer containing a majority carrier of a second conductivity type opposite to the first conductivity type.

Abstract: Provided is a nitride semiconductor device including: a nitride semiconductor layer over a substrate wherein the nitride semiconductor has a two-dimensional electron gas (2DEG) channel inside; a drain electrode in ohmic contact with the nitride semiconductor layer; a source electrode spaced apart from the drain electrode, in Schottky contact with the nitride semiconductor layer, and having an ohmic pattern in ohmic contact with the nitride semiconductor layer inside; a dielectric layer formed on the nitride semiconductor layer between the drain electrode and the source electrode and on at least a portion of the source electrode; and a gate electrode disposed on the dielectric layer to be spaced apart from the drain electrode, wherein a portion of the gate electrode is formed over a drain-side edge portion of the source electrode with the dielectric layer interposed therebetween, and a manufacturing method thereof.

Abstract: Enhancement mode III-nitride devices are described. The 2DEG is depleted in the gate region so that the device is unable to conduct current when no bias is applied at the gate. Both gallium face and nitride face devices formed as enhancement mode devices.

Abstract: Semiconductor heterostructures to reduce short channel effects are generally described. In one example, an apparatus includes a semiconductor substrate, one or more buffer layers coupled to the semiconductor substrate, a first barrier layer coupled to the one or more buffer layers, a back gate layer coupled to the first barrier layer wherein the back gate layer includes a group III-V semiconductor material, a group II-VI semiconductor material, or combinations thereof, the back gate layer having a first bandgap, a second barrier layer coupled to the back gate layer wherein the second barrier layer includes a group III-V semiconductor material, a group II-VI semiconductor material, or combinations thereof, the second barrier layer having a second bandgap that is relatively larger than the first bandgap, and a quantum well channel coupled to the second barrier layer, the quantum well channel having a third bandgap that is relatively smaller than the second bandgap.

Abstract: An integrated circuit structure includes a substrate and a first and a second plurality of III-V semiconductor layers. The first plurality of III-V semiconductor layers includes a first bottom barrier over the substrate; a first channel layer over the first bottom barrier; and a first top barrier over the first channel layer. A first field-effect transistor (FET) includes a first channel region, which includes a portion of the first channel layer. The second plurality of III-V semiconductor layers is over the first plurality of III-V semiconductor layers and includes a second bottom barrier; a second channel layer over the second bottom barrier; and a second top barrier over the second channel layer. A second FET includes a second channel region, which includes a portion of the second channel layer.

Abstract: In one embodiment, the disclosure relates to an electronic device successively comprising from its base to its surface: (a) a support layer, (b) a channel layer adapted to contain an electron gas, (c) a barrier layer and (d) at least one ohmic contact electrode formed by a superposition of metallic layers, a first layer of which is in contact with the barrier layer. The device is remarkable in that the barrier layer includes a contact region under the ohmic contact electrode(s). The contact region includes at least one metal selected from the metals forming the superposition of metallic layers. Furthermore, a local alloying binds the contact region and the first layer of the electrode(s).

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 includes a group III nitride semiconductor supporting base, a GaN based semiconductor region, an active layer, and a GaN semiconductor region. The primary surface of the group III nitride semiconductor supporting base is not any polar plane, and forms a finite angle with a reference plane that is orthogonal to a reference axis extending in the direction of a c-axis of the group III nitride semiconductor. The GaN based semiconductor region, grown on the semipolar primary surface, includes a semiconductor layer of, for example, an n-type GaN based semiconductor doped with silicon. A GaN based semiconductor layer of an oxygen concentration of 5×1016 cm?3 or more provides an active layer, grown on the primary surface, with an excellent crystal quality.

Abstract: Enhancement mode III-nitride devices are described. The 2DEG is depleted in the gate region so that the device is unable to conduct current when no bias is applied at the gate. Both gallium face and nitride face devices formed as enhancement mode devices.

Abstract: Nanowire and larger, post-based HEMTs, arrays of such HEMTs, and methods for their manufacture are provided. In one embodiment, a HEMT can include a III-N based core-shell structure including a core member (e.g., GaN), a shell member (e.g., AlGaN) surrounding a length of the core member and a two-dimensional electron gas (2-DEG) at the interface therebetween. The core member including a nanowire and/or a post can be disposed over a doped buffer layer and a gate material can be disposed around a portion of the shell member. Exemplary methods for making the nanowire HEMTs and arrays of nanowire HEMTs can include epitaxially forming nanowire(s) and epitaxially forming a shell member from each formed nanowire. Exemplary methods for making the post HEMTs and arrays of post HEMTs can include etching a III-N layer to form III-N post(s) followed by formation of the shell member(s).

Abstract: A high electron mobility transistor includes a substrate, a buffer layer, a channel layer, a spacer layer, a schottky layer and a cap layer. The buffer layer is formed on the substrate. The channel layer is formed on the buffer layer, in which the channel layer comprises a superlattice structure formed with a plurality of indium gallium arsenide thin films alternately stacked with a plurality of indium arsenide thin films. The spacer layer is formed on the channel layer. The schottky layer is formed on the spacer layer. The cap layer is formed on the schottky layer.

Abstract: An improved HEMT formed from a GaN material system is disclosed which has reduced gate leakage current and eliminates the problem of current constrictions resulting from deposition of the gate metal over the step discontinuities formed over the gate mesa. One or more GaN based materials are layered and etched to form a gate mesa with step discontinuities defining source and drain regions. In order to reduce the leakage current, the step discontinuities are back-filled with an insulating material, such as silicon nitride (SiN), forming a flat surface relative to the source and drain regions, to enable to the gate metal to lay flat. By back-filling the source and drain regions with an insulating material, leakage currents between the gate and source and the gate and drain are greatly reduced. In addition, current constrictions resulting from the deposition of the gate metal over a step discontinuity are virtually eliminated.