Xidian University

Yue Hao

Jincheng Zhang

Dong Wang

Jing Ning

Weihang Zhang

Xiaohua Ma

Peijun Ma

Kunlu Song

Junwei Liu

Boyu Wang

Zhihong Liu

Yachao Zhang

Lu Hao

Shenglei Zhao

Shihui Wang

Hong Zhou

Ling Yang

Zhiyu Lin

Xiaowei Zhou

Peixian Li

Chaochao Yan

Xuefeng Zheng

Chunfu Zhang

Jiaqi Zhang

Guofang Yang

Shuaishuai Dong

Yichang Wu

Dazheng Chen

Peng Ji

Chi Zhang

Chong Wang

Zhibin Chen

Yanqing Jia

Yingzhe Wang

Zhenling Tang

A material structure for silicon-based gallium nitride microwave and millimeter-wave devices and a manufacturing method thereof are provided. The material structure includes: a silicon substrate; a dielectric layer of high thermal conductivity, disposed on an upper surface of the silicon substrate, and an uneven first patterned interface being formed between the dielectric layer and the silicon substrate; a buffer layer, disposed on an upper surface of the dielectric layer, and an uneven second patterned interface being formed between the buffer layer and the dielectric layer; a channel layer, disposed on an upper surface of the buffer layer; and a composite barrier layer, disposed on an upper surface of the channel layer. In the material structure, the uneven patterned interfaces increase contact areas of the interfaces, a thermal boundary resistance and a thermal resistance of device are reduced, and a heat dissipation performance of device is improved.

Material structure for low thermal resistance silicon-based gallium nitride microwave and millimeter-wave devices and manufacturing method thereof

A method for preparing an AlN based template having a Si substrate and a method for preparing a GaN based epitaxial structure having a Si substrate are provided. The method for preparing the AlN based template having the Si substrate, which includes: providing the Si substrate; growing an AlN nucleation layer on the Si substrate; and introducing an ion passing through the AlN nucleation layer and into the Si substrate. After the AlN nucleation layer is prepared on the Si substrate, the ions are introduced into the Si substrate and the AlN nucleation layer through the AlN nucleation layer. In this way, types of the introduced ions can be expanded. In addition, a carrier concentration at an interface between the Si substrate and the AlN nucleation layer and a carrier concentration in the AlN nucleation layer can also be reduced.

Methods for preparing AlN based template having Si substrate and GaN based epitaxial structure having Si substrate

A low turn-on voltage GaN diode having an anode metal with a consistent crystal orientation and a preparation method thereof. The low turn-on voltage GaN diode having an anode metal with a consistent crystal orientation provided by the present disclosure includes a substrate layer, a GaN buffer layer, a GaN channel layer and an AlGaN barrier layer, which are arranged in sequence from bottom to top; a cathode arranged on the AlGaN barrier layer; a groove arranged in the GaN channel layer and the AlGaN barrier layer, and an anode provided on a bottom and a side wall of the groove and part of the AlGaN barrier layer; a dielectric layer provided on an uncovered portion of the AlGaN barrier layer; wherein, a contact portion of the anode with the groove and the AlGaN barrier layer is W or Mo metal with a crystal orientation of &#x3c;100&#x3e;.

Low turn-on voltage GaN diodes having anode metal with consistent crystal orientation and preparation method thereof

A bidirectional blocking monolithic heterogeneous integrated Cascode-structure field effect transistor, which mainly solves a problem that the existing monolithic heterogeneous integrated Cascode-structure field effect transistor has no reverse blocking characteristic. The field effect transistor includes a substrate, a GaN buffer layer, an AlGaN barrier layer and a SiN isolation layer, wherein an isolation groove is etched in the middle of the SiN isolation layer, a Si active layer is printed on the SiN isolation layer on one side of the isolation groove so as to prepare a Si metal oxide semiconductor field effect transistor, and a GaN high-electron-mobility transistor is prepared on the other side of the isolation groove, and a drain electrode of the GaN high-electron-mobility transistor is in Schottky contact with the AlGaN barrier layer to form a bidirectional blocking monolithic heterogeneous integrated Cascode-structure field effect transistor.

Bidirectional blocking monolithic heterogeneous integrated cascode-structure field effect transistor, and manufacturing method thereof

The present invention discloses an epitaxial lift-off process of graphene-based gallium nitride (GaN), and principally solves the existing problems about complex lift-off technique, high cost, and poor quality of lift-off GaN films. The invention is achieved by: first, growing graphene on a well-polished copper foil by CVD method; then, transferring a plurality of layers of graphene onto a sapphire substrate; next, growing GaN epitaxial layer on the sapphire substrate with a plurality of graphene layers transferred by the metal organic chemical vapor deposition (MOCVD) method; finally, lifting off and transferring the GaN epitaxial layer onto a target substrate with a thermal release tape. With graphene, the present invention relieves the stress generated by the lattice mismatch between substrate and epitaxial layer; moreover, the present invention readily lifts off and transfers the epitaxial layer to the target substrate by means of weak Van der Waals forces between epitaxial layer and graphene.

Epitaxial lift-off process of graphene-based gallium nitride

The present invention discloses a method for growing gallium nitride based on graphene and magnetron sputtered aluminum nitride, and a gallium nitride thin film. The method according to an embodiment comprises: spreading graphene over a substrate; magnetron sputtering an aluminum nitrite onto the graphene-coated substrate to obtain a substrate sputtered with aluminum nitrite; placing the substrate sputtered with aluminum nitride into a MOCVD reaction chamber and heat treating the substrate to obtain a heat treated substrate; growing an aluminum nitride transition layer on the heat treated substrate and a first and a second gallium nitride layer having different V-III ratios, respectively. The gallium nitrate thin film according to an embodiment comprises the following structures in order from bottom to top: a substrate (), a graphene layer (), an aluminum nitride nucleation layer () fabricated by using a magnetron sputtering method, an aluminum nitride transition layer () grown by MOCVD, and a first and a second gallium nitrate layer () having different V-III ratios.

Method for growing gallium nitride based on graphene and magnetron sputtered aluminum nitride

The present disclosure provides a method for characterizing ohmic contact electrode performance of a semiconductor device. The method comprises: preparing two sets of testing patterns on a semiconductor device; testing resistance values of the two sets of testing patterns respectively; calculating a sheet resistance of an ohmic contact area according to the obtained resistance values; and evaluating the ohmic contact electrode performance of the semiconductor device according to the sheet resistance of the ohmic contact electrode.

Method for characterizing ohmic contact electrode performance of semiconductor device

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.

Ultraviolet light emitting diode devices and methods for fabricating the same

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Xi'an, China

Yue Hao