Abstract: A semiconductor device includes: a compound semiconductor substrate; a buffer layer, a channel layer, and a Schottky junction forming layer sequentially disposed on the compound semiconductor substrate, the buffer layer, the channel layer, and the Schottky junction forming layer each being compound semiconductor materials; a source electrode and a drain electrode located on the Schottky junction forming layer; and a gate electrode disposed between the source and drain electrodes and forming a Schottky junction with the Schottky junction forming layer. The dopant impurity concentration in the channel layer is inversely proportional to the third power of depth into the channel layer from a top surface of the channel layer. The gate electrode has a gate length in a range from 0.2 ?m to 0.6 ?m.

Abstract: A semiconductor device reduces the on-resistance and, at the same time, raises the breakdown voltage. The drain electrode 20 of the semiconductor device runs through cap layer 13 and electron supply layer 12 and gets to a position lower than two-dimensional electron gas layer 14 in channel layer 11. Thus, the drain electrode 20 directly contacts the channel layer 11, the electron supply layer 12 and the cap layer 13. Angles (acute angles) ?, ø and ? are formed by the drain electrode 20 and the channel layer 11, the electron supply layer 12 and the cap layer 13 as viewed in the direction in which a hetero interface is formed (the transverse direction in FIG. 1) and relationships of ø<? and ø?? are established. In other words, ø is made smallest among the angles and the drain electrode 20 is remarkably tapered particularly at the position of the electron supply layer 12.

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: A novel semiconductor transistor is presented. The semiconductor structure has a gate region forming a channel with repetitive patterns in the direction perpendicular to the current flow, so that the portion of its channel that is not strictly planar contributes to a significant reduction of the silicon area occupied by the device. It offers the advantage of lower on-resistance for the same silicon area while improving on its dynamic performances. The additional cost to shape the channel region of the device in periodic repetitive patterns is minimum, which makes the present invention easy to implement in any conventional CMOS process technology and very cost effective.

Abstract: A transistor structure comprising an active semiconductor layer with metal source and drain contacts formed in electrical contact with the active layer. A gate contact is formed between the source and drain contacts for modulating electric fields within the active layer. A spacer layer is formed above the active layer and a conductive field plate formed above the spacer layer, extending a distance Lf from the edge of the gate contact toward the drain contact. The field plate is electrically connected to the gate contact and provides a reduction in the peak operational electric field.

Abstract: An aspect of the present invention inheres in a semiconductor device includes a semiconductor region, a source electrode and a drain electrode, which are provided on a main surface of the semiconductor region, a gate electrode exhibiting normally-off characteristics, the gate electrode being provided above the main surface of the semiconductor region while interposing a p-type material film therebetween, and being arranged between the source electrode and the drain electrode, and a fourth electrode that is provided on the main surface of the semiconductor region, and is arranged between the gate electrode and the drain electrode.

Abstract: A nitride semiconductor device includes: a first nitride semiconductor layer; a second nitride semiconductor layer formed on the first nitride semiconductor layer and having a wider band gap than the first nitride semiconductor layer; and a third nitride semiconductor layer formed on the second nitride semiconductor layer. A region of the third nitride semiconductor layer located below the gate electrode is formed with a control region having a p-type conductivity, and a region of the third nitride semiconductor layer located between the gate electrode and each of the source electrode and the drain electrode is formed with a high resistive region having a higher resistance than the that of the control region.

Abstract: Disclosed is an RF power FET or HEMT including an electrically-conductive substrate, a grounding metallization layer disposed on a bottom surface of the electrically-conductive substrate, an active area comprising at least one cell including source, gate and drain electrodes disposed over a top surface of the electrically-conductive substrate, and an electrically-conductive shallow trench electrically connecting the source electrode to the grounding metallization layer by way of the electrically-conductive substrate. This configuration results in the effective RF ground being very close to the active area of the FET in order to reduce parasitic source inductance and resistance. This results in potentially higher gain, higher saturation point, higher 3rd-order intercept, more efficient combining of the input RF signal, and more efficient extraction of the output RF signal.

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

Abstract: A high electron mobility transistor includes a free-standing supporting base having a III nitride region, a first III nitride barrier layer which is provided on the first III nitride barrier layer, a III nitride channel layer which is provided on the first III nitride barrier layer and forms a first heterojunction with the first III nitride barrier layer, a gate electrode provided on the III nitride channel layer so as to exert an electric field on the first heterojunction, a source electrode on the III nitride channel layer and the first III nitride barrier, and a drain electrode on the III nitride channel layer and the first III nitride barrier. The III nitride channel layer has compressive internal strain, and the piezoelectric field of the III nitride channel layer is oriented in the direction from the supporting base towards the first III nitride barrier layer.

Abstract: A vertical type GaN series field effect transistor having excellent pinch-off characteristics is provided. A compound semiconductor device includes a conductive semiconductor substrate, a drain electrode formed on a bottom surface of the conductive semiconductor substrate, a current blocking layer formed on a top surface of the conductive semiconductor substrate, made of high resistance compound semiconductor or insulator, and having openings, an active layer of compound semiconductor burying the openings and extending on an upper surface of the current blocking layer, a gate electrode formed above the openings and above the active layer, and a source electrode formed laterally spaced from the gate electrode and formed above the active layer.

Abstract: Methods of forming semiconductor devices having customized contacts are provided including providing a first insulator layer and patterning the first insulator layer such that the first insulator layer defines at least one contact window. A second insulator layer is provided on the first insulator layer and in the at least one contact window such that the second insulator layer at least partially fills the at least one contact window. A first portion of the second insulator layer is etched such that a second portion of the second insulator layer remains in the at least one contact window to provide at least one modified contact window having dimensions that are different than dimensions of the at least one contact window. Related methods and devices are also provided.

Abstract: A semiconductor device includes: a substrate 101, a first nitride semiconductor layer 104S which includes a plurality of nitride semiconductor layers formed on the substrate 101, and has a channel region; a second semiconductor layer 105 which is formed on the first nitride semiconductor layer 104S, and has a conductivity type opposite a conductivity type of the channel region; a conductive layer which is in contact with the second semiconductor layer 105, and includes a metal layer 107 or a high carrier concentration semiconductor layer having a carrier concentration of 1×1018 cm?3 or higher; an insulating layer 110 formed on the conductive layer; a gate electrode 111 formed on the insulating layer 110; and a source electrode 108 and a drain electrode 109 formed to laterally sandwich the second semiconductor layer 105.

Abstract: A semiconductor device and a fabrication method of the semiconductor device, the semiconductor device including: a substrate; a nitride based compound semiconductor layer placed on the substrate and doped with a first transition metal atom; an aluminum gallium nitride layer (AlxGa1?xN) (where 0.1<=x<=1) placed on the nitride based compound semiconductor layer; a nitride based compound semiconductor layer placed on the aluminum gallium nitride layer (AlxGa1?xN) (where 0.1<=x<=1) and doped with a second transition metal atom; an aluminum gallium nitride layer (AlyGa1?yN) (where 0.1<=y<=1) placed on the nitride based compound semiconductor layer doped with the second transition metal atom; and a gate electrode, a source electrode, and a drain electrode which are placed on the aluminum gallium nitride layer (AlyGa1?yN) (where 0.1<=y<=1).

Abstract: An Enhancement-mode (E-mode) high electron mobility transistor (HEMT) includes a channel layer with a 2-Dimensional Electron Gas (2DEG), a barrier layer inducing the 2DEG in the channel layer, source and drain electrodes on the barrier layer, a depletion layer on the barrier layer between the source and drain electrodes, and a gate electrode on the depletion layer. The barrier layer is recessed below the gate electrode and the depletion layer covers a surface of the recess and extends onto the barrier layer around the recess.

Abstract: A method for fabricating a transistor and the resulting transistor is disclosed. The method generally includes steps (A) to (E). Step (A) may form a high mobility layer. The high mobility layer is generally configured to carry a two-dimensional electron gas. Step (B) may form a planar layer on the high mobility layer. Step (C) may form a barrier layer on the planar layer. Step (D) may form a doped layer on the barrier layer. The doped layer is generally a low bandgap III-V semiconductor. Step (E) may form a gate in contact with the doped layer. The gate may be separated from both a source and a drain by corresponding ungated recess regions. The high mobility layer, the planar layer, the barrier layer, the doped layer, the source, the gate and the drain are generally configured as a pseudomorphic high electron mobility transistor.

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: In an aspect of a semiconductor device, there are provided a substrate, a transistor including an electron transit layer and an electron supply layer formed over the substrate, a nitride semiconductor layer formed over the substrate and connected to a gate of the transistor, and a controller controlling electric charges moving in the nitride semiconductor layer.

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: A multiple field plate transistor includes an active region, with a source, a drain, and a gate. A first spacer layer is over the active region between the source and the gate and a second spacer layer over the active region between the drain and the gate. A first field plate on the first spacer layer is connected to the gate. A second field plate on the second spacer layer is connected to the gate. A third spacer layer is on the first spacer layer, the second spacer layer, the first field plate, the gate, and the second field plate, with a third field plate on the third spacer layer and connected to the source. The transistor exhibits a blocking voltage of at least 600 Volts while supporting a current of at least 2 Amps with an on resistance of no more than 5.0 m?-cm2, of at least 600 Volts while supporting a current of at least 3 Amps with an on resistance of no more than 5.3 m?-cm2, of at least 900 Volts while supporting a current of at least 2 Amps with an on resistance of no more than 6.

Abstract: A manufacturing method of a device having series-connected HEMTs is presented. Transistors are formed on a substrate and integratedly serial-connected as an integrated device by interconnection wires. Therefore, the voltage of the device is the sum of the voltages across each transistors so that the device can have high breakdown voltage.

Abstract: In one example, we describe a new high performance AlGaN/GaN metal-insulator-semiconductor heterostructure field-effect transistor (MISHFET), which was fabricated using HfO2 as the surface passivation and gate insulator. The gate and drain leakage currents are drastically reduced to tens of nA, before breakdown. Without field plates, for 10 ?m of gate-drain spacing, the off-state breakdown voltage is 1035V with a specific on-resistance of 0.9 m?-cm2. In addition, there is no current slump observed from the pulse measurements. This is the best performance reported on GaN-based, fast power-switching devices on sapphire, up to now, which efficiently combines excellent device forward, reverse, and switching characteristics. Other variations, features, and examples are also mentioned here.

Abstract: An enhancement mode (E-mode) HEMT is provided that can be used for analog and digital applications. In a specific embodiment, the HEMT can be an AlN/GaN HEMT. The subject E-mode device can be applied to high power, high voltage, high temperature applications, including but not limited to telecommunications, switches, hybrid electric vehicles, power flow control and remote sensing. According to an embodiment of the present invention, E-mode devices can be fabricated by performing an oxygen plasma treatment with respect to the gate area of the HEMT. The oxygen plasma treatment can be, for example, an O2 plasma treatment. In addition, the threshold voltage of the E-mode HEMT can be controlled by adjusting the oxygen plasma exposure time. By using a masking layer protecting regions for depletion mode (D-mode) devices, D-mode and E-mode devices can be fabricated on a same chip.

Abstract: The buffer breakdown of a group III-N HEMT on a p-type Si substrate is significantly increased by forming an n-well in the p-type Si substrate to lie directly below the metal drain region of the group III-N HEMT. The n-well forms a p-n junction which becomes reverse biased during breakdown, thereby increasing the buffer breakdown by the reverse-biased breakdown voltage of the p-n junction and allowing the substrate to be grounded. The buffer layer of a group III-N HEMT can also be implanted with n-type and p-type dopants which are aligned with the p-n junction to minimize any leakage currents at the junction between the substrate and the buffer layer.

Abstract: The Si substrate of a group III-N HEMT is formed in layers that define a p-n junction which electrically isolates an upper region of the Si substrate from a lower region of the Si substrate. As a result, the upper region of the Si substrate can electrically float, thereby obtaining a full buffer breakdown voltage, while the lower region of the Si substrate can be attached to a package by way of a conductive epoxy, thereby significantly improving the thermal conductivity of the group III-N HEMT and minimizing undesirable floating-voltage regions.

Abstract: A semiconductor device includes: a semiconductor base; a hetero semiconductor region which is in contact with the semiconductor base and which has a band gap different from that of the semiconductor base; a first electrode connected to the hetero semiconductor region; and a second electrode forming an ohmic contact to the semiconductor base. The hetero semiconductor region includes a laminated hetero semiconductor region formed by laminating a plurality of semiconductor layers in which crystal alignment is discontinuous at a boundary between at least two layers.

Abstract: An object of the present invention is to reduce on-state resistance and increases reliability in a semiconductor device having an electrode formed in a recessed structure. As illustrated in FIG. 1B, a first insulating layer 103 is formed. Then, as illustrated in FIG. 1C, a photolithography process is carried out to form a photoresist pattern 104. Subsequently, as illustrated in FIG. 1D, dry etching is applied to the first insulating layer 103. Then, as illustrated in FIG. 1E, a laminated semiconductor structure is etched. Next, in this state, wet etching is applied to the first insulating layer 103 as illustrated in FIG. 1F. Next, in this state, an electrode material 105 is formed on the entire exposed surface as illustrated in FIG. 1G. Finally, as illustrated in 1H, the photoresist pattern 104 is removed.

Abstract: A compound semiconductor device includes: a compound semiconductor layer; a source electrode; a drain electrode; a gate electrode; a field plate; and a low-conductivity region. The low-conductivity region is arranged within a region immediately below the field plate in a region where the two-dimensional carrier gas layer is formed, and has lower conductivity than a region above which the field plate or the gate electrode is not arranged in the region where the two-dimensional carrier gas layer is formed.

Abstract: A III-nitride device having a support substrate that may include a first silicon body, a second silicon body, an insulation body interposed between the first and second silicon bodies, and a III-nitride body formed over the second silicon body.

Abstract: The present invention includes methods for producing GaAs/Si composites, GaAs/Si composites, apparatus for preparing GaAs/Si composites, and a variety of electronic and photoelectric circuits and devices incorporating GaAs/Si composites of the present invention.

Abstract: According to an example embodiment, a high electron mobility transistor (HEMT) includes a substrate, a buffer layer on the substrate, a channel layer on the buffer layer, and a barrier structure on the channel layer. The buffer layer includes a 2-dimensional electron gas (2DEG). A polarization of the barrier structure varies in a region corresponding to a gate electrode. The HEMT further includes and the gate electrode, a source electrode, and a drain electrode on the barrier structure.

Abstract: A semiconductor device includes a first semiconductor layer, a second semiconductor layer, a two-dimensional carrier gas layer, a first main electrode, a second main electrode, a first gate electrode, and a second gate electrode. The first gate electrode is provided between a part of the first main electrode and a part of the second main electrode opposite to the part of the first main electrode. The second gate electrode is provided between another part of the first main electrode and another part of the second main electrode opposite to the another part of the first main electrode with a separation region interposed between the first gate electrode and the second gate electrode. The second gate electrode is controlled independently of the first gate electrode.

Abstract: Semiconductor transistor devices and related fabrication methods are provided. An exemplary transistor device includes a layer of semiconductor material having a channel region defined therein and a gate structure overlying the channel region. Recesses are formed in the layer of semiconductor material adjacent to the channel region, such that the recesses extend asymmetrically toward the channel region. The transistor device also includes stress-inducing semiconductor material formed in the recesses. The asymmetric profile of the stress-inducing semiconductor material enhances carrier mobility in a manner that does not exacerbate the short channel effect.

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: An i-GaN layer (electron transit layer), an n-GaN layer (compound semiconductor layer) formed over the i-GaN layer (electron transit layer), and a source electrode, a drain electrode and a gate electrode formed over the n-GaN layer (compound semiconductor layer) are provided. A recess portion is formed inside an area between the source electrode and the drain electrode of the n-GaN layer (compound semiconductor layer) and at a portion separating from the gate electrode.

Abstract: A normally off semiconductor device with a reduced off-state leakage current, which is applicable to a power switching element, includes: a substrate; an undoped GaN layer formed above the substrate; an undoped AlGaN layer formed on the undoped GaN layer; a source electrode and a drain electrode, formed on the undoped GaN layer or the undoped AlGaN layer; a P-type GaN layer formed on the undoped AlGaN layer and disposed between the source electrode and the drain electrode; and a gate electrode formed on the P-type GaN layer, wherein the undoped GaN layer includes an active region including a channel and an inactive region not including the channel, and the P-type GaN layer is disposed to surround the source electrode.

Abstract: A nitride semiconductor device includes a semiconductor layer stack including a first nitride semiconductor layer and a second nitride semiconductor layer stacked in this order on a substrate. A p-type third nitride semiconductor layer is selectively formed on the semiconductor layer stack, and a gate electrode is formed on the third nitride semiconductor layer. A first ohmic electrode and a second ohmic electrode are formed on regions of the semiconductor layer stack located at both sides of the third nitride semiconductor layer, respectively. A first gate electrode forms a Schottky contact with the third nitride semiconductor layer.

Abstract: A semiconductor device includes a substrate; a buffer layer; and a compound semiconductor layer laminated on the substrate with the buffer layer in between. The buffer layer has a dislocation density in a plane in parallel to an in-plane direction thereof, so that a volume resistivity of the buffer layer becomes a substantially maximum value.

Abstract: A field-effect transistor includes a semi-insulating substrate, a source electrode, a drain electrode, a gate electrode, the electrodes being provided on the semi-insulating substrate, and a buried gate region which is provided under the gate electrode and in which an impurity is doped, wherein a concave slit is provided in the semi-insulating substrate, the slit being located between the gate electrode and the drain electrode and being adjacent to the buried gate region at the side of the drain electrode.

Abstract: A semiconductor device includes a GaN electron transport layer provided over a substrate; a first AlGaN electron supply layer provided over the GaN electron transport layer; an AlN electron supply layer provided over the first AlGaN electron supply layer; a second AlGaN electron supply layer provided over the AlN electron supply layer; a gate recess provided in the second AlGaN electron supply layer and the AlN electron supply layer; and a gate electrode provided over the gate recess.

Abstract: A semiconductor sensor determines physical and/or chemical properties of a medium, in particular a pH sensor. The semiconductor sensor has an electronic component with a sensitive surface, said component being constructed for its part on the basis of semiconductors with a large band gap (wide-gap semiconductor). The sensitive surface is provided at least in regions with a functional layer sequence which has an ion-sensitive surface. The functional layer sequence has at least one layer which is impermeable at least for the medium and/or the materials or ions to be determined.

Abstract: A transistor with source and drain electrodes formed in contact with an active region and a gate between the source and drain electrodes and in contact with the active region. A first spacer layer is on at least part of the active region surface between the gate and drain electrodes and between the gate and source electrodes. The gate comprises a generally t-shaped top portion that extends toward the source and drain electrodes. A field plate is on the spacer layer and under the overhang of at least one section of the gate top portion. The field plate is at least partially covered by a second spacer layer that is on at least part of the first active layer surface and between the gate and drain and between the gate and source. At least one conductive path electrically connects the field plate to the source electrode or the gate.

Abstract: A compound semiconductor device includes a substrate having an opening formed from the rear side thereof; a compound semiconductor layer disposed over the surface of the substrate; a local p-type region in the compound semiconductor layer, partially exposed at the end of the substrate opening; and a rear electrode made of a conductive material, disposed in the substrate opening so as to be connected to the local p-type region.

Abstract: A semiconductor device includes: a substrate; a semiconductor stacked structure, provided over the substrate, including an electron transit layer and an electron supply layer; a gate electrode, a source electrode, and a drain electrode provided over the semiconductor stacked structure; a gate pad, a source pad, and a drain pad provided over the gate electrode, the source electrode, and the drain electrode, and connected to the gate electrode, the source electrode, and the drain electrode, respectively; and a conductive layer provided under the gate pad, the source pad, and the drain pad, wherein a distance between the gate pad and the source pad is smaller than a distance between the gate pad and the drain pad.

Abstract: A heterojunction field-effect semiconductor device has a main semiconductor region comprising two layers of dissimilar materials such that a two-dimensional electron gas layer is generated along the heterojunction between the two layers. A source and a drain electrode are placed in spaced positions on a major surface of the main semiconductor region and electrically coupled to the 2DEG layer. Between these electrodes, a gate electrode is received in a recess in the major surface of the main semiconductor region via a p-type metal oxide semiconductor film and insulating film, whereby a depletion zone is normally created in the 2DEG layer, making the device normally off. The p-type metal oxide semiconductor film of high hole concentration serves for the normally-off performance of the device with low gate leak current, and the insulating film for further reduction of gate leak current.

Abstract: A semiconductor device includes: a first semiconductor layer; a second semiconductor layer; a two-dimensional carrier gas layer; a source electrode; a drain electrode; a gate electrode; and an auxiliary electrode located above the two-dimensional carrier gas layer between the gate electrode and the drain electrode. Channel resistance of the two-dimensional carrier gas layer between the gate electrode and the auxiliary electrode is set higher than channel resistance of the two-dimensional carrier gas layer between the gate electrode and the source electrode.

Abstract: A hybrid device including a silicon based MOSFET operatively connected with a GaN based device.

Abstract: A semiconductor device includes a substrate, a carrier transit layer disposed above the substrate, a compound semiconductor layer disposed on the carrier transit layer, a source electrode disposed on the compound semiconductor layer, a first groove disposed from the back of the substrate up to the inside of the carrier transit layer while penetrating the substrate, a drain electrode disposed in the inside of the first groove, a gate electrode located between the source electrode and the first groove and disposed on t he compound semiconductor layer, and a second groove located diagonally under the source electrode and between the source electrode and the first groove and disposed from the back of the substrate up to the inside of the carrier transit layer while penetrating the substrate.

Abstract: A semiconductor device includes a first semiconductor layer of a first conductivity type, a second semiconductor layer formed in contact with the first semiconductor layer, and a third semiconductor layer of a second conductivity type formed in contact with the second semiconductor layer, the first semiconductor layer provided with a first semiconductor region at a given distance from an interface between the first semiconductor layer and the second semiconductor layer, and an impurity concentration of the first semiconductor region higher than an impurity concentration of the first semiconductor layer except where the first semiconductor region is formed.

Abstract: Disclosed herein is a pseudomorphic high electron mobility transistor (PHEMT) power device (1) including a semi-insulating substrate (2); an epitaxial substrate (3) formed on the semi-insulating substrate (2) a contact layer (19). The contact layer (19) includes a lightly doped contact layer (20) formed on the Schottky layer (18), and a highly doped contact layer (21) formed on the lightly doped contact layer (20) and having a doping concentration higher than the lightly doped contact layer (20). The PHEMT power device (1) further includes a—wide recess (23) formed to penetrate the highly doped contact layer (21) and a narrow recess (24) formed in the wide recess (23) to penetrate the lightly doped contact layer (20). The gate electrode (6) is formed in the narrow recess (24) and in Schottky contact with the Schottky layer (18).