Beijing Huajin Chuangwei Technology Co.

Beijing, China

Beijing Huajin Chuangwei Technology Co.

Beijing, China
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Yan J.,CAS Institute of Semiconductors | Wang Q.,CAS Institute of Semiconductors | Wang Q.,University of Posts and Telecommunications | Wang X.,CAS Institute of Semiconductors | And 6 more authors.
Journal of Applied Physics | Year: 2016

In this paper, a theoretical study of N-polar GaN/AlxGa1-xN/GaN heterostructures is conducted systematically. The dependence of two-dimensional hole gas (2DHG, at the bottom AlxGa1-xN/GaN interface) and electron gas (2DEG, at the upper GaN/AlxGa1-xN interface) sheet densities on variables, such as GaN top layer thickness, AlxGa1-xN back barrier thickness, and Al content, is investigated. The effect of n-type doping in AlxGa1-xN and δ-doping concentrations in the GaN buffer on 2DHG and 2DEG sheet densities is also presented. For the unintentionally doped structure, the 2DHG-induced electric field E2DHG provides the only driving force in the 2DEG formation. Thus, in order to get high dense of 2DEG in such heterostructure, 2DEG and 2DHG shall coexist through proper AlxGa1-xN back barrier design. While for intentionally doped structure (with the n-type doped AlxGa1-xN back barrier layer or δ-doped GaN buffer layer), ionized donor-induced electric field Edonor is another driving force for 2DEG. The obtained insight offers indications for the structure design of the N-polar GaN/AlxGa1-xN/GaN high electron mobility transistors. © 2016 Author(s).


Kang H.,Key Laboratory Of Semiconductor Materials Scienceinstitute Of Semiconductorschinese Academy Of Sciencesbeijing100083Pr China | Xiao H.,Key Laboratory Of Semiconductor Materials Scienceinstitute Of Semiconductorschinese Academy Of Sciencesbeijing100083Pr China | Wang C.,Key Laboratory Of Semiconductor Materials Scienceinstitute Of Semiconductorschinese Academy Of Sciencesbeijing100083Pr China | Jiang L.,Key Laboratory Of Semiconductor Materials Scienceinstitute Of Semiconductorschinese Academy Of Sciencesbeijing100083Pr China | And 9 more authors.
Physica Status Solidi (A) Applications and Materials Science | Year: 2015

In this paper, AlGaN/GaN- and GaN/AlGaN/GaN-based Schottky barrier diodes (SBDs) were fabricated and studied for comparison. The recorded electrical characteristics of the devices show that the introduction of a GaN cap layer can evidently reduce the reverse leakage current and suppress the forward current decay of the devices. What is more important, the GaN/AlGaN/GaN-based SBDs are capable of greatly alleviating the unrecoverable degradation of the reverse characteristics, which was observed in the device without a GaN cap layer when the device was under long time reverse dc stress. Detailed analyses were discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Li W.,KeyLab of Semiconductor Materials Science | Wang Q.,Institute Of Semiconductorschinese Academy Of Sciencesbeijingpr China | Wang C.,KeyLab of Semiconductor Materials Science | Yin H.,KeyLab of Semiconductor Materials Science | And 4 more authors.
Physica Status Solidi (A) Applications and Materials Science | Year: 2016

In this paper, (InxAl1-xN/AlN)MQWs/InN/GaN heterostructure with a (InxAl1-xN/AlN)MQWs barrier layer and an InN channel layer is presented. The numerical calculations of 2DEG characteristics are made using a self-consistent solution of the Schrödinger and Poisson equations. The influence of (InxAl1-xN/AlN)MQWs and InN layer on band diagrams, 2DEG sheet density and carrier confinement are studied. The results show that an InN insert layer can improve the carrier-confinement ability without degrading the 2DEG sheet density in the heterostructure. The (InxAl1-xN/AlN)MQWs/InN/GaN heterostructure has both a larger 2DEG sheet density and better confinement of 2DEG than conventional InAlN/GaN and AlGaN/GaN heterojunctions. The 2DEG sheet density is as dramatically large as 3.85×1013cm-2 with an AlN thickness of 1.5nm, an In0.18Al0.82N thickness of 1.5nm, an InN thickness of 0.5nm, and pair number of 5. In addition, the influence of AlN thickness, InAlN thickness, indium content, and pair number on the 2DEG sheet density of the (InxAl1-xN/AlN)MQWs/InN/GaN heterostructure has been studied. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Kang H.,CAS Institute of Semiconductors | Wang Q.,University of Posts and Telecommunications | Xiao H.,CAS Institute of Semiconductors | Wang C.,CAS Institute of Semiconductors | And 12 more authors.
Physica Status Solidi (A) Applications and Materials Science | Year: 2015

In this paper, AlGaN/GaN- and GaN/AlGaN/GaN-based Schottky barrier diodes (SBDs) were fabricated and studied for comparison. The recorded electrical characteristics of the devices show that the introduction of a GaN cap layer can evidently reduce the reverse leakage current and suppress the forward current decay of the devices. What is more important, the GaN/AlGaN/GaN-based SBDs are capable of greatly alleviating the unrecoverable degradation of the reverse characteristics, which was observed in the device without a GaN cap layer when the device was under long time reverse dc stress. Detailed analyses were discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Yan J.,CAS Institute of Semiconductors | Wang X.,CAS Institute of Semiconductors | Wang X.,Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices | Wang X.,ISCAS XJTU Joint Laboratory of Functional Materials and Devices for Informatics | And 12 more authors.
Journal of Applied Physics | Year: 2014

In this paper, a numerical study of InxGa1 -xN/AlyGa1- yN/GaN heterostructure is presented. The dependence of two-dimensional electron gas (2DEG) and two-dimensional hole gas (2DHG) sheet densities on variables, such as InxGa1- xN layer thickness and In content, and AlyGa 1-yN barrier layer thickness and Al content, are systematically investigated. The effect of P-type doping in In xGa1-xN on 2DEG and 2DHG sheet densities in this heterostructure is also studied. It is shown that the strong reverse electric field in InxGa1-xN cap layer contributes to the depletion of 2DEG at the AlyGa 1-yN/GaN interface. When InxGa1 -xN layer thickness and In content increases, 2DEG sheet density decreases significantly. P-type doping shows less influence on 2DEG compared to the polarization electric field in InxGa1 -xN layer. In addition, there exist critical values for all the variables beyond which 2DHG appears at the interface of In xGa1-xN/AlyGa 1-yN. Once 2DHG appears, it will prevent 2DEG from being further depleted. With proper design of AlyGa 1-yN layer, the coexistence of 2DEG and 2DHG in InxGa1-xN/AlyGa 1-yN/GaN structure can be avoided, showing that this structure has great potential in the fabrication of enhancement mode (E-mode) high electron mobility transistors. © 2014 AIP Publishing LLC.


Yan J.-D.,CAS Institute of Semiconductors | Wang Q.,CAS Institute of Semiconductors | Wang Q.,University of Posts and Telecommunications | Wang X.-L.,CAS Institute of Semiconductors | And 13 more authors.
Chinese Physics Letters | Year: 2015

Direct-current transfer characteristics of (InGaN)/AlGaN/AlN/GaN heterojunction field effect transistors (HFETs) are presented. A drain current plateau (IDS = 32.0mA/mm) for VGS swept from +0.7V to -0.6V is present in the transfer characteristics of InGaN/AlGaN/AlN/GaN HFETs. The theoretical calculation shows the coexistence of two-dimensional electron gas (2DEG) and two-dimensional hole gas (2DHG) in InGaN/AlGaN/AlN/GaN heterostructures, and the screening effect of 2DHG to the 2DEG in the conduction channel can explain this current plateau. Moreover, the current plateau shows the time-dependent behavior when IDS-VGSscans repeated are conducted. The obtained insight provides indication for the design in the fabrication of GaN-based super HFETs. © 2015 Chinese Physical Society and IOP Publishing Ltd.


Cui L.,CAS Institute of Semiconductors | Yin H.,CAS Institute of Semiconductors | Jiang L.,CAS Institute of Semiconductors | Wang Q.,CAS Institute of Semiconductors | And 10 more authors.
Journal of Semiconductors | Year: 2015

Fe doping is an effective method to obtain high resistivity GaN epitaxial material. But in some cases, Fe doping could result in serious deterioration of the GaN material surface topography, which will affect the electrical properties of two dimensional electron gas (2DEG) in HEMT device. In this paper, the influence of Fe doping on the surface topography of GaN epitaxial material is studied. The results of experiments indicate that the surface topography of Fe-doped GaN epitaxial material can be effectively improved and the resistivity could be increased after increasing the growth rate of GaN materials. The GaN material with good surface topography can be manufactured when the Fe doping concentration is 9 × 1019 cm-3. High resistivity GaN epitaxial material which is 1 × 109 Ω•cm is achieved. © 2015 Chinese Institute of Electronics.


Cui L.,CAS Institute of Semiconductors | Wang Q.,CAS Institute of Semiconductors | Wang Q.,Xian University of Posts and Telecommunications | Wang X.-L.,CAS Institute of Semiconductors | And 9 more authors.
Chinese Physics Letters | Year: 2015

A novel multi-finger gate high electron mobility transistor (HEMT) is designed to reduce the peak electric field value at the drain-side gate edge when the device is at off-state. The effective gate length (Leff ) of the multi-finger gate device is smaller than that of the field plate gate device. In this work, field plate gate, five-finger gate and ten-finger gate devices are simulated. The results of the simulation indicate that the multi-finger gate device has a lower peak value than the device with the gate field plate. Moreover, this value would be further reduced when the number of gate fingers is increased. In addition, it has the potential to make the HEMT work in a higher frequency since it has a lower effective length of gate. © 2015 Chinese Physical Society and IOP Publishing Ltd.

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