120 results about "Aluminium gallium nitride" patented technology

A zinc oxide (ZnO) field effect transistor exhibits large input amplitude by using a gate insulating layer. A channel layer and the gate insulating layer are sequentially laminated on a substrate. A gate electrode is formed on the gate insulating layer. A source contact and a drain contact are disposed at the both sides of the gate contact and are electrically connected to the channel layer via openings. The channel layer is formed from n-type ZnO. The gate insulating layer is made from aluminum nitride/aluminum gallium nitride (AlN/AlGaN) or magnesium zinc oxide (MgZnO), which exhibits excellent insulation characteristics, thus increasing the Schottky barrier and achieving large input amplitude. If the FET is operated in the enhancement mode, it is operable in a manner similar to a silicon metal oxide semiconductor field effect transistor (Si-MOS-type FET), resulting in the formation of an inversion layer.

A nitride semiconductor device according to one embodiment of the present invention comprises: a non-doped first aluminum gallium nitride (Al_xGa_1-xN (0≦x≦1)) layer which is formed as a channel layer; a non-doped or n type second aluminum gallium nitride (Al_yGa_1-yN (0≦x≦1,x<y)) layer which is formed on the first aluminum gallium nitride layer as a barrier layer; an aluminum nitride (AlN) film which is formed on the second aluminum gallium nitride layer as a gate insulating film lower layer; an aluminum oxide (Al₂O₃) film which is formed on the aluminum nitride film as a gate insulating film upper layer; a source electrode and a drain electrode which are formed as first and second main electrodes to be electrically connected to the second aluminum gallium nitride layer, respectively; and a gate electrode which is formed on the aluminum oxide film as a control electrode.

The invention discloses a method for enhancing the antistatic ability of GaN-based light-emitting diode. The epitaxial wafer structure of the light-emitting diode sequentially comprises an underlay, alow-temperature buffer layer, an unadulterated GaN high-temperature buffer layer, an aluminum gallium nitride/ GaN superlattice structure, the unadulterated GaN high-temperature buffer layer, an N type contact layer, an N type GaN conductive layer, a light-emitting layer multiple quantum well structure MQW, a P type aluminum gallium nitride electric barrier layer, a P type GaN conductive layer and a P type contact layer in a sequence from down to up. In the invention, the aluminum gallium nitride/ GaN superlattice periodic structure is inserted in the unalloyed GaN high temperature buffer layer. The insertion of the aluminum gallium nitride/ GaN superlattice periodic structure can effectively improve crystal quality of materials, thereby enhancing the antistatic ability of the GaN-based light-emitting diode and improving the reliability and the stability of devices.

The present invention relates to a high voltage and high power gallium nitride (GaN) transistor structure. In general, the GaN transistor structure includes a sub-buffer layer that serves to prevent injection of electrons into a substrate during high voltage operation, thereby improving performance of the GaN transistor structure during high voltage operation. Preferably, the sub-buffer layer is aluminum nitride, and the GaN transistor structure further includes a transitional layer, a GaN buffer layer, and an aluminum gallium nitride Schottky layer.

The invention discloses an LED (Light Emitting Diode) epitaxial structure with a P (Positive) type superlattice and a preparation method thereof. The epitaxial structure comprises a substrate, wherein a GaN (Gallium Nitride) buffer layer, an undoped GaN layer, an n (negative) type GaN layer, a multi-quantum well luminous layer, a first P type GaN layer, a P type AlGaN (Aluminium Gallium Nitride) electronic blocking layer and a second P type GaN layer are sequentially arranged on the substrate from bottom to top, and the P type superlattice formed by a PInGaN (P type Indium Gallium Nitride) potential well layer and a PAlGaN potential barrier layer in a periodic interactive overlapping way is arranged between the P type AlGaN electronic blocking layer and the second P type GaN layer. The PInGaN potential well layer in the P type superlattice generates and constrains a great number of holes for the formation of a two-dimensional hole high-density state; the PAlGaN potential barrier layer hinders the escape of the holes; in such a way, the transverse spreading of the holes is improved, the electron overflow can be prevented, the hole injection efficiency is increased and the electron and hole recombination probability is improved; and therefore, the brightness of a chip can be improved by 5-10%.

One embodiment of a quantum well structure comprises an active region including active layers that comprise quantum wells and barrier layers wherein some or all of the active layers are p type doped. P type doping some or all of the active layers improves the quantum efficiency of III-V compound semiconductor light emitting diodes by locating the position of the P-N junction in the active region of the device thereby enabling the dominant radiative recombination to occur within the active region. In one embodiment, the quantum well structure is fabricated in a cluster tool having a hydride vapor phase epitaxial (HVPE) deposition chamber with a eutectic source alloy. In one embodiment, the indium gallium nitride (InGaN) layer and the magnesium doped gallium nitride (Mg—GaN) or magnesium doped aluminum gallium nitride (Mg—AlGaN) layer are grown in separate chambers by a cluster tool to avoid indium and magnesium cross contamination. Doping of group III-nitrides by hydride vapor phase epitaxy using group III-metal eutectics is also described. In one embodiment, a source is provided for HVPE deposition of a p-type or an n-type group III-nitride epitaxial film, the source including a liquid phase mechanical (eutectic) mixture with a group III species. In one embodiment, a method is provided for performing HVPE deposition of a p-type or an n-type group III-nitride epitaxial film, the method including using a liquid phase mechanical (eutectic) mixture with a group III species.

In a nitride semiconductor device according to one embodiment of the invention, a p-type gallium nitride (GaN) layer electrically connected to a source electrode and extending and projecting to a drain electrode side with respect to a gate electrode is formed on an undoped or n-type aluminum gallium nitride (AlGaN) layer serving as a barrier layer.

The invention relates to a gallium nitride based light-emitting diode, in particular to a high-power gallium nitride based light-emitting diode structure; the high-power gallium nitride based light-emitting diode comprises a substrate, an N-type gallium nitride layer arranged on the substrate, a AlGaN cavity barrier layer arranged on a high table top of the N-type gallium nitride layer, an asymmetrical multiple quantum well active layer arranged on the cavity barrier layer, a P-type gallium nitride layer arranged on the asymmetrical multiple quantum well active layer, a P+-InGaN conducting layer arranged on the P-type gallium nitride layer, and an indium titanium oxide electrode layer which is arranged on the P+-InGaN conducting layer from bottom to top; a silicon dioxide passivation layer is arranged on the top surface of the whole light-emitting diode and the side surface connected to the high and low table tops, an N electrode is arranged on the lower table top of the N-type gallium nitride layer, and a P-electrode is arranged in the middle of the indium titanium oxide electrode layer. The light-emitting diode structure can improve the injection efficiency of the cavity and improve the photoelectric conversion efficiency.

A high electron mobility transistor (HEMT) is disclosed that includes a semi-insulating silicon carbide substrate, an aluminum nitride buffer layer on the substrate, an insulating gallium nitride layer on the buffer layer, an active structure of aluminum gallium nitride on the gallium nitride layer, a passivation layer on the aluminum gallium nitride active structure, and respective source, drain and gate contacts to the aluminum gallium nitride active structure.

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 (Al_xGa_1-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 (Al_xGa_1-xN) (where 0.1<=x<=1) and doped with a second transition metal atom; an aluminum gallium nitride layer (Al_yGa_1-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 (Al_yGa_1-yN) (where 0.1<=y<=1). Accordingly, piezo charge is inactivated, leakage current and current collapse are reduced, high frequency characteristics can be improved by obtaining a high resistivity semiconductor layer, and stable high frequency performance can be obtained.

High electron mobility transistors (HEMTs) and methods of fabricating HEMTs are provided. Devices according to embodiments of the present invention include a gallium nitride (GaN) channel layer and an aluminum gallium nitride (AlGaN) barrier layer on the channel layer. A first ohmic contact is provided on the barrier layer to provide a source electrode and a second ohmic contact is also provided on the barrier layer and is spaced apart from the source electrode to provide a drain electrode. A GaN-based cap segment is provided on the barrier layer between the source electrode and the drain electrode. The GaN-based cap segment has a first sidewall adjacent and spaced apart from the source electrode and may have a second sidewall adjacent and spaced apart from the drain electrode. A non-ohmic contact is provided on the GaN-based cap segment to provide a gate contact. The gate contact has a first sidewall which is substantially aligned with the first sidewall of the GaN-based cap segment. The gate contact extends only a portion of a distance between the first sidewall and the second sidewall of the GaN-based cap segment.

A method of growing planar non-polar m-plane or semi-polar III-Nitride material, such as an m-plane gallium nitride (GaN) epitaxial layer, wherein the III-Nitride material is grown on a suitable substrate, such as an m-plane Sapphire substrate, using hydride vapor phase epitaxy (HVPE). The method includes in-situ pretreatment of the substrate at elevated temperatures in the ambient of ammonia and argon, growing an intermediate layer such as an aluminum nitride (AlN) or aluminum-gallium nitride (AlGaN) on the annealed substrate, and growing the non-polar m-plane III-Nitride epitaxial layer on the intermediate layer using HVPE.

A UV LED device and the method for fabricating the same are provided. The device has aluminum nitride nucleating layers, an intrinsic aluminum gallium nitride epitaxial layer, an n-type aluminum gallium nitride barrier layer, an active region, a first p-type aluminum gallium nitride barrier layer, a second p-type aluminum gallium nitride barrier layer, and a p-type gallium nitride cap layer arranged from bottom to top on a substrate. A window region is etched in the p-type gallium nitride cap layer for emitting the light generated.

The present disclosure involves a method of fabricating a semiconductor device. A surface of a silicon wafer is cleaned. A first buffer layer is then epitaxially grown on the silicon wafer. The first buffer layer contains an aluminum nitride (AlN) material. A second buffer layer is then epitaxially grown on the first buffer layer. The second buffer layer includes a plurality of aluminum gallium nitride (AlxGa1-xN) sub-layers. Each of the sub-layers has a respective value for x that is between 0 and 1. A value of x for each sub-layer is a function of its position within the second buffer layer. A first gallium nitride (GaN) layer is epitaxially grown over the second buffer layer. A third buffer layer is then epitaxially grown over the first GaN layer. A second GaN layer is then epitaxially grown over the third buffer layer.

The invention discloses a method for improving antistatic capability of a gallium nitride based light emitting diode. The method comprises the following steps: selecting a substrate; growing a gallium nitride nucleating layer on the substrate; growing an involuntary doped gallium nitride layer on the gallium nitride nucleating layer; growing an aluminum gallium nitride/ gallium nitride superlattice insertion layer on the involuntary doped gallium nitride layer; growing an N-type doped gallium nitride layer on the aluminum gallium nitride/ gallium nitride superlattice insertion layer; growing an indium gallium aluminum nitride multiple quantum-well light-emitting layer on the N-type doped gallium nitride layer; growing a P-type doped indium gallium aluminum nitride layer on the indium gallium aluminum nitride multiple quantum-well light-emitting layer; and growing a P-type doped gallium nitride layer on the P-type doped indium gallium aluminum nitride layer. By utilizing the method provided by the invention, the stress caused by lattice mismatch in an epitaxial layer can be modulated, simultaneously the dislocation in the epitaxial layer of the GaN (gallium nitride) can be deflected and combined, thus the density of threading dislocation in the epitaxial layer developed subsequently is reduced, the material quality is improved, and the antistatic capability of the light emitting diode is improved.

The invention provides an epitaxial structure for improving luminous efficiency. The epitaxial structure for improving the luminous efficiency sequentially comprises a substrate, a first GaN (Gallium Nitride) buffer layer, a second GaN buffer layer, an N-type GaN layer, a multi-quantum well (MQW) structure, a light-emitting layer multi-quantum well structure, a p-type GaN layer, a p-type AlGaN (aluminium gallium nitride) layer, a p-type GaN layer and a p-type contact layer from the bottom up, wherein the multi-quantum well structure consists of n layers of InxGa1-XN/GaN multi-quantum wells; the widths, the depths and the barrier heights of the n layers of the multi-quantum wells increase layer by layer; the barrier widths of the n layers of the multi-quantum wells decrease layer by layer; the well widths increasing layer by layer and the barrier widths decreasing layer by layer form regular correspondence; and n is an integer in a range of 2-12. A preparation method of the epitaxial structure for improving the luminous efficiency can optimize concentration distribution of electrons, reduce stresses generated in growth processes of multi-quantum wells, reduce a quantum confined stark effect (QCSE) and improve the luminous efficiency of the multi-quantum wells.

Aluminum gallium nitride (AlxGa1-xN, 0<x<1) is employed as a substrate of a Group III nitride compound semiconductor device. In light-emitting diodes and laser diodes employing the substrate, crack generation is prevented, even when a thick cladding layer formed of aluminum gallium nitride (AlxGa1-xN, 0<x<1) is stacked on the substrate. The smaller the difference in Al compositional proportion between the substrate and an aluminum gallium nitride (AlxGa1-xN, 0<x<1) layer, the less likely the occurrence of crack generation.