718 results about "Wide-bandgap semiconductor" patented technology

High electron mobility transistors are provided that include a non-uniform aluminum concentration AlGaN based cap layer having a high aluminum concentration adjacent a surface of the cap layer that is remote from the barrier layer on which the cap layer is provided. High electron mobility transistors are provided that include a cap layer having a doped region adjacent a surface of the cap layer that is remote from the barrier layer on which the cap layer is provided. Graphitic BN passivation structures for wide bandgap semiconductor devices are provided. SiC passivation structures for Group III-nitride semiconductor devices are provided. Oxygen anneals of passivation structures are also provided. Ohmic contacts without a recess are also provided.

A normally-off cascode power switch circuit is disclosed fabricated in wide bandgap semiconductor material such as silicon carbide or gallium nitride and which is capable of conducting current in the forward and reverse direction under the influence of a positive gate bias. The switch includes cascoded junction field effect transistors (JFETs) that enable increased gain, and hence blocking voltage, while minimizing specific on-resistance.

A method of producing a trench gate type MOSFET is provided in which each intersection trench is formed as a two-stage trench structure. A gate trench is backfilled with a mask material and the mask material is then patterned to form a mask used for forming each intersection trench. The intersection trench intersecting the gate trench is provided so as to be deeper than the gate trench. A Schottky electrode is provided in the bottom of each intersection trench 10p. In this manner, there is provided a trench gate type semiconductor device and a method of producing the same, in which: the cell pitch can be reduced even when a wide band gap semiconductor is used as a main semiconductor substrate; good ohmic contacts can be obtained; and an excessive electric field is prevented from being applied to an insulating film in the bottom of each trench.

High electron mobility transistors are provided that include a non-uniform aluminum concentration AlGaN based cap layer having a high aluminum concentration adjacent a surface of the cap layer that is remote from the barrier layer on which the cap layer is provided. High electron mobility transistors are provided that include a cap layer having a doped region adjacent a surface of the cap layer that is remote from the barrier layer on which the cap layer is provided. Graphitic BN passivation structures for wide bandgap semiconductor devices are provided. SiC passivation structures for Group III-nitride semiconductor devices are provided. Oxygen anneals of passivation structures are also provided. Ohmic contacts without a recess are also provided.

The present invention is a novel field effect transistor having a channel region formed from a narrow bandgap semiconductor film formed on an insulating substrate. A gate dielectric layer is formed on the narrow bandgap semiconductor film. A gate electrode is then formed on the gate dielectric. A pair of source/drain regions formed from a wide bandgap semiconductor film or a metal is formed on opposite sides of the gate electrode and adjacent to the low bandgap semiconductor film.

A wide band gap semiconductor device is disclosed. A first trench in a gate electrode part and a second trench in a source electrode part (Schottky diode part) are disposed so that the first and second trenches are close to each other while and the second trench is deeper than the first trench. A metal electrode is formed in the second trench to form a Schottky junction on a surface of an n-type drift layer in the bottom of the second trench. Further, a p+-type region is provided in part of the built-in Schottky diode part being in contact with the surface of the n-type drift layer, preferably in the bottom of the second trench. The result is a wide band gap semiconductor device which is small in size and low in on-resistance and loss, and in which electric field concentration applied on a gate insulating film is relaxed to suppress lowering of withstand voltage to thereby increase avalanche breakdown tolerance at turning-off time.

A field effect transistor comprising a silicon containing body is provided. After formation of a gate dielectric, gate electrode, and a first gate spacer, a drain side trench is formed and filled with a wide band gap semiconductor material. Optionally, a source side trench may be formed and filled with a silicon germanium alloy to enhance an on-current of the field effect transistor. Halo implantation and source and drain ion implantation are performed to form various doped regions. Since the wide band gap semiconductor material as a wider band gap than that of silicon, impact ionization is reduced due to the use of the wide band gap semiconductor material in the drain, and consequently, a breakdown voltage of the field effect transistor is increased compared to transistors employing silicon in the drain region.

A photovoltaic cell or other optoelectronic device having a wide-bandgap semiconductor used in the window layer. This wider bandgap is achieved by using a semiconductor composition that is not lattice-matched to the cell layer directly beneath it and/or to the growth substrate. The wider bandgap of the window layer increases the transmission of short wavelength light into the emitter and base layers of the photovoltaic cell. This in turn increases the current generation in the photovoltaic cell. Additionally, the wider bandgap of the lattice mismatched window layer inhibits minority carrier injection and recombination in the window layer.

An inverter circuit (120) is configured so as to perform synchronous rectification by six switching elements (130). The switching element (130) is formed of an unipolar device (SiC MOSFET in this case) using a wideband gap semiconductor. The inverter circuit (120) uses the body diode (131) of SiC MOSFET (130) as a freewheeling diode during synchronous rectification.

A conventional DRAM needs to be refreshed at an interval of several tens of milliseconds to hold data, which results in large power consumption. In addition, a transistor therein is frequently turned on and off; thus, deterioration of the transistor is also a problem. These problems become significant as the memory capacity increases and transistor miniaturization advances. A transistor is provided which includes a wide-gap semiconductor and has a trench structure including a trench for a gate electrode and a trench for element isolation. Even when the distance between a source electrode and a drain electrode is decreased, the occurrence of a short-channel effect can be suppressed by setting the depth of the trench for the gate electrode as appropriate.

Alternate layers of wide band gap and narrow band gaps of different kinds of semiconductors are used to form multiple channels of a FET. The channels are doped or formed as 2-DEG/2-DHG in narrow band semiconductor by charge supply layer in the wide band gap semiconductor. The different kinds of semiconductors form heterojunctions to confine the electrons/holes in separate thin spikes layers. A number of spikes (3-10 nm thick) of different doped or 2-DEG/2-DHG concentrations in various channels can result in overall electron concentration gradient such as a 1/x³ electron/hole concentrations profile. Such an electron/hole concentration gradient can result in a linear variation of drain current with voltage to obtain a wide dynamic range.

The invention was about low voltage metal organic chemistry vapour deposition equipment and the preparation. The system was made up of gas transport system, reaction chamber, sample pretreatment chamber, control system, tail gas treatment system. The sample pretreatment chamber was made up of ectotheca, sample pallet shelf, sample desk, gas bleed spore, plasma generator, flange, plate valve of switch between the sample pretreatment chamber and reaction chamber, flange of plate valve, magnetic transmit bar, magnetic cannula, flange of transmit bar. Its advantages include increased the growing of ZnO film and uniformity, benefit for the P type and intermingle of high impedance.

A power switching device includes an optically controlled component using a semiconducting carbon nanotube. An optical signal transmitted over an optical fiber controls the conductivity of the nanotube. The nanotube transmits a signal controlled by the optical signal to a wide-bandgap semiconductor power switch, which switches the power.

A method and the benefits resulting from the product thereof are disclosed for the growth of large, low-defect single-crystals of tetrahedrally-bonded crystal materials. The process utilizes a uniquely designed crystal shape whereby the direction of rapid growth is parallel to a preferred crystal direction. By establishing several regions of growth, a large single crystal that is largely defect-free can be grown at high growth rates. This process is particularly suitable for producing products for wide-bandgap semiconductors, such as SiC, GaN, AlN, and diamond. Large low-defect single crystals of these semiconductors enable greatly enhanced performance and reliability for applications involving high power, high voltage, and/or high temperature operating conditions.

A semiconductor device including a memory cell formed using a wide bandgap semiconductor, for example, an oxide semiconductor is provided. The semiconductor device includes a potential change circuit having a function of outputting a potential lower than a reference potential for reading data from the memory cell. With the use of the wide bandgap semiconductor, an off-state current of a transistor included in the memory cell can be sufficiently reduced, and the semiconductor device which can hold data for a long period can be provided.

A semiconductor device such as a reverse blocking type switching element is provided with a switching element made of a wide band gap semiconductor on the side of a first major plane where a first terminal is formed, while the wide band gap semiconductor is operable at a high voltage and in low loss. In a reverse blocking type switching element having a hetero junction diode for blocking a reverse direction current on the side of a second major plane where a second terminal is formed, a silicon semiconductor region is provided in a side surface of the semiconductor so as to prevent a deterioration of a withstanding voltage of the hetero junction diode.