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Liu X.-B.,Hebei Semiconductor Research Institute | Zhao Y.-Z.,Hebei Semiconductor Research Institute | Wang S.-D.,Hebei Semiconductor Research Institute | Wang Z.-Q.,Hebei Semiconductor Research Institute
2016 International Forum on Wide Bandgap Semiconductors China, IFWS 2016 - Conference Proceedings | Year: 2016

In this paper a novel package based on GaN MMICs chipset, comprising a driver amplifier and a power amplifier using Si-based packing technique will be presented. The GaN HEMT on SiC power amplifiers is superior to GaAs/Si based FET due to its higher power density and wider band gap. The thermal matching and thermal conductivity of the package are taken into consideration in order to avoid the high channel temperature lower the performance of the power amplifier. For an operation frequency band from 14 to 18 GHz, the module achieves beyond 39 dBm of output power under pulsed conditions Vgs = -2 V and Vds = +28 V, small signal gain of around 36.8 dB. The chipset are assembled in a 9.7 mm ×6.5 mm × 0.81 mm Si-based package. © 2016 IEEE.


PubMed | Hebei Semiconductor Research Institute and Peking University
Type: | Journal: Scientific reports | Year: 2016

The high-field transport characteristics of nearly lattice-matched InAlN/GaN heterostructures with different barrier thickness were investigated. It is found that the current in the InAlN/GaN heterostructures with ultrathin barrier shows unsaturated behaviors (or secondary rising) at high voltage, which is different from that of AlGaN/GaN heterostructures. This phenomenon is more obvious if the barrier thickness is thinner and the channel width is narrower. The experimental results demonstrate that it is the increasing carrier density excited from the more defect states by the hot electrons with larger electron saturation velocity that results in the unsaturated current behaviors in InAlN/GaN heterostructures. Our results pave a way for further optimizing InAlN barrier design and improving the reliability of InAlN/GaN HEMTs.


Feng Z.H.,Hebei Semiconductor Research Institute | Zhou R.,Hebei Semiconductor Research Institute | Xie S.Y.,University of Electronic Science and Technology of China | Yin J.Y.,Hebei Semiconductor Research Institute | And 5 more authors.
IEEE Electron Device Letters | Year: 2010

Enhancement-mode (E-mode) AlGaN/GaN heterojunction field effect transistors (HFETs) with a nominal gate length of 0.35 μm are fabricated on a SiC substrate by fluorine plasma ion implantation without the use of gate recess. The threshold voltage is measured to be +0.2 V by linear extrapolation from the transfer characteristics. The E-mode device exhibits a saturation drain current density of 735 mA/mm at a gate bias of 4 V, a peak transconductance of 269 mS/mm, a current-gain cutoff frequency fT of 39 GHz, and a maximum oscillation frequency fmax of 91 GHz. At 18 GHz, the fabricated E-mode device exhibits a maximum output power density of 3.65 W/mm, a linear gain of 11.6 dB, and a peak power-added efficiency of 42%. This is the first report of the large-signal performance of AlGaN/GaN E-mode HFETs in the Ku-band. © 2006 IEEE.


Zhang S.,Harbin Institute of Technology | Liu B.,Hebei Semiconductor Research Institute | Yin J.Y.,Hebei Semiconductor Research Institute | Sun H.H.,Harbin Institute of Technology | And 2 more authors.
Journal of Physics D: Applied Physics | Year: 2011

The growth mechanisms of vertical compositional inhomogeneities were investigated in lattice-matched AlInN films prepared by metalorganic chemical vapour deposition. X-ray diffraction and secondary ion mass spectrometry measurements demonstrated a fluctuation of the indium (In) atomic fraction at the initial growth stage. Some In droplets formed on the surface of the inhomogeneous AlInN films, when In was excess caused by the initial Al-rich AlInN layer. The compositional inhomogeneities were attributed to the self-assembled In droplets by increasing the surface In content. © 2011 IOP Publishing Ltd.


PubMed | Hebei University and Hebei Semiconductor Research Institute
Type: Journal Article | Journal: Dalton transactions (Cambridge, England : 2003) | Year: 2016

CdO:Ag nanocomposites with metallic Ag nanoparticles embedded in the polycrystalline CdO matrix were synthesized by the solid-state reaction method. The addition of Ag led to increased grain boundaries of CdO and created numerous CdO/Ag interfaces. By incorporating Ag into the CdO matrix, the power factor was increased which was probably due to the carrier energy filtering effect induced by the enhanced energy-dependent scattering of electrons. In addition, reduced thermal conductivity was also achieved by stronger phonon scattering from grain boundaries, CdO/Ag interfaces and Ag nanoparticles. These concomitant effects resulted in enhanced ZT values for all CdO:Ag nanocomposites, demonstrating that the strategy of introducing metallic Ag nanoparticles into the CdO host was very effective in optimizing the thermoelectric performance.


Feng Z.H.,Hebei Semiconductor Research Institute
2014 IEEE International Conference on Electron Devices and Solid-State Circuits, EDSSC 2014 | Year: 2014

Carbon electronics based on diamond and graphene field effect transistors have attracted significant attention for potential RF applications. Graphene is a 2 dimensional atomic layer of carbon atoms with unique electronic transport properties, such as outstanding carrier mobility and high carrier saturation velocity, which make graphene an excellent candidate for applications in high-speed analog electronics. Diamond also shows several physical properties that make it interesting for high power applications. In this paper, we discuss the current status and the prospects and problems of graphene and diamond transistors. Those properties of graphene and diamond relevant for transistors, including preparation of high-quality graphene film in large-scale, weak current saturation of the graphene transistors, growth of single crystalline and electronic diamond film, and doping of the diamond are reviewed. Our works on graphene and diamond electronics are also introduced. With the deep going of the investigation, carbon electronics should be used in the near future. © 2014 IEEE.


Yu C.,Hebei Semiconductor Research Institute | Liu Q.,Hebei Semiconductor Research Institute | Li J.,Hebei Semiconductor Research Institute | Lu W.,Hebei Semiconductor Research Institute | And 3 more authors.
Applied Physics Letters | Year: 2014

We investigate the temperature dependent electrical transport properties of quasi-free standing bilayer graphene on 4H-SiC (0001) substrate. Three groups of monolayer epitaxial graphene and corresponding quasi-free standing bilayer graphene with different crystal quality and layer number homogeneity are prepared. Raman spectroscopy and atomic-force microscopy are used to obtain their morphologies and layer number, and verify the complete translation of buffer layer into graphene. The highest room temperature mobility reaches 3700 cm2/V·s for the quasi-free standing graphene. The scattering mechanism analysis shows that poor crystal quality and layer number inhomogeneity introduce stronger interacting of SiC substrate to the graphene layer and more impurities, which limit the carrier mobility of the quasi-free standing bilayer graphene samples. © 2014 AIP Publishing LLC.


Zhao J.,Shandong University | Lin Z.,Shandong University | Luan C.,Shandong University | Chen Q.,Shandong University | And 4 more authors.
Superlattices and Microstructures | Year: 2015

Based on the forward current-voltage (I-V) characteristics and the capacitance-voltage ( C-V ) curves between the gate and source, a method to determine the strain of the AlGaN barrier layer under the gate in AlGaN/AlN/GaN heterostructure field-effect transistors (HFETs) has been presented. With this proposed method, the strain of the AlGaN barrier layer for the prepared AlGaN/AlN/GaN HFETs with the normal-Ohmic contacts and the side-Ohmic contacts has been analyzed and determined. It was found that the normal- Ohmic contact processing greatly affected the strain of the AlGaN barrier layer and the tensile strain of the AlGaN barrier layer was gradually reduced from the middle to the Ohmic contacts for the AlGaN/AlN/GaN HFETs with the normal-Ohmic contacts, while the strain of the AlGaN barrier layer was weakly affected by the side-Ohmic contact processing. © 2014 Elsevier Ltd. All rights reserved.


Hu Z.,Hebei Semiconductor Research Institute | Gao X.,Hebei Semiconductor Research Institute | Cai S.,Hebei Semiconductor Research Institute
Proceedings of International Conference on ASIC | Year: 2011

A multiple-pole electro-thermal equivalent subcircuit model of power GaN HEMT is proposed. A quick and reliable electrical approach for direct extraction of thermal resistances and thermal capacitances is presented. Good agreement between measured and simulated I-V characteristics with thermal effect validates the electro-thermal model. © 2011 IEEE.


Feng Z.H.,Hebei Semiconductor Research Institute | Yu C.,Hebei Semiconductor Research Institute | Li J.,Hebei Semiconductor Research Institute | Liu Q.B.,Hebei Semiconductor Research Institute | And 4 more authors.
Carbon | Year: 2014

Owing to its ultra high carrier mobility, graphene transistor shows great application potential as high-frequency electronics. Intrinsic cutoff frequency (fT) of 427 GHz has been reported. But the maximum oscillation frequency (fmax) remains low, limiting its use in practical radio-frequency (RF) circuits. Here, we report an ultra clean self-aligned graphene transistors fabrication by pre-deposition of gold film on graphene as protection layer. This improved self-aligned fabrication keeps graphene away from any possible contamination, which makes our graphene transistors show good gate coupling and less parasitics, thus good dc and RF performances. The 100 nm gate-length graphene transistor exhibits a fmax of 105 GHz. Our study shows a pathway to fabrication of high-performance graphene transistors for future application in RF circuits. © 2014 Elsevier Ltd. All rights reserved.

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