基于蓝宝石衬底的高性能AlGaN/GaN二维电子气材料与HEMT器件

利用低压MOCVD技术在蓝宝石衬底上生长了高性能的AlGaN/GaN二维电子气(2DEG)材料,室温和77K温度下的电子迁移率分别为946和2578cm2/(V*s),室温和77K温度下2DEG面密度分别为1.3×1013和1.27×1013cm-2.并利用AlGaN/GaN二维电子气材料制造出了高性能的HEMT器件,栅长为1μm,源漏间距为4μm,最大电流密度为485mA/mm(VG=1V),最大非本征跨导为170mS/mm(VG=0V),截止频率和最高振荡频率分别为6.7和24GHz.     

分子束外延AlGaN/GaN异质结场效应晶体管材料

用自组装的氨源分子束外延 (NH3-MBE)系统和射频等离子体辅助分子束外延 (PA-MBE)系统在 C面蓝宝石衬底上外延了优质 Ga N以及 Al Ga N/Ga N二维电子气材料。Ga N膜 (1 .2 μm厚 )室温电子迁移率达3 0 0 cm2 /V· s,背景电子浓度低至 2× 1 0 1 7cm- 3。双晶 X射线衍射 (0 0 0 2 )摇摆曲线半高宽为 6arcmin。 Al Ga N/Ga N二维电子气材料最高的室温和 77K二维电子气电子迁移率分别为 73 0 cm2 /V·s和 1 2 0 0 cm2 /V· s,相应的电子面密度分别是 7.6× 1 0 1 2 cm- 2和 7.1× 1 0 1 2 cm- 2 ;用所外延的 Al Ga N/Ga N二维电子气材料制备出了性能良好的 Al Ga N/Ga N HFET(异质结场效应晶体管 ) ,室温跨导为 5 0 m S/mm(栅长 1 μm) ,截止频率达 1 3 GHz(栅长 0 .5μm)。该器件在 3 0 0°C出现明显的并联电导 ,这可能是材料中的深中心在高温被激活所致     

MBE生长的跨导为186mS/mm的AlGaN/GaN HEMT

用分子束外延 ( MBE)技术研制出了 Al Ga N/Ga N高电子迁移率晶体管 ( HEMT)材料 ,其室温迁移率为 10 35cm2 /V· s、二维电子气浓度为 1.0× 10 13 cm - 2 ;77K迁移率为 2 6 53cm2 /V· s、二维电子气浓度为 9.6× 10 12 cm- 2 。用此材料研制了栅长为 1μm、栅宽为 80μm、源 -漏间距为 4μm的 Al Ga N/Ga N HEMT,其室温最大非本征跨导为 186 m S/mm、最大漏极饱和电流密度为 92 5m A/mm、特征频率为 18.8GH z。另外 ,还研制了具有 2 0个栅指 (总栅宽为 2 0× 80μm =1.6 mm )的大尺寸器件 ,该器件的最大漏极饱和电流为 1.33A。     

RF-MBE生长AlGaN/GaN极化感应二维电子气材料

用射频等离子体辅助分子束外延技术 (RF- MBE)在 C面蓝宝石衬底上外延了高质量的 Ga N膜以及 Al Ga N/Ga N极化感应二维电子气材料 .所外延的 Ga N膜室温背景电子浓度为 2× 10 1 7cm- 3 ,相应的电子迁移率为 177cm2 /(V· s) ;Ga N (0 0 0 2 ) X射线衍射摇摆曲线半高宽 (FWHM)为 6′;Al Ga N/Ga N极化感应二维电子气材料的室温电子迁移率为 730 cm2 /(V· s) ,相应的电子气面密度为 7.6× 10 1 2 cm- 2 ;用此二维电子气材料制作的异质结场效应晶体管 (HFET)室温跨导达 5 0 m S/mm (栅长 1μm) ,截止频率达 13GHz(栅长 0 .5 μm)     

RF-MBE生长的AlGaN/GaN高电子迁移率晶体管特性

用射频分子束外延技术研制出了室温迁移率为10 35 cm2 /(V·s) ,二维电子气浓度为1.0×10 1 3cm- 2 ,77K迁移率为2 6 5 3cm2 /(V·s) ,二维电子气浓度为9.6×10 1 2 cm- 2 的Al Ga N/Ga N高电子迁移率晶体管材料.用此材料研制的器件(栅长为1μm,栅宽为80μm,源-漏间距为4μm )的室温非本征跨导为186 m S/m m,最大漏极饱和电流密度为92 5 m A/m m,特征频率为18.8GHz.     

肖特基C-V法研究Al_xGa_(1-x)N/GaN异质结界面二维电子气

通过对 Pt/ Al0 .2 2 Ga0 .78N/ Ga N肖特基二极管的 C- V测量 ,研究分析了 Al0 .2 2 Ga0 .78N/ Ga N异质结界面二维电子气 (2 DEG)浓度及其空间分布 .测量结果表明 ,Al0 .2 2 Ga0 .78N/ Ga N异质结界面 2 DEG浓度峰值对应的深度在界面以下 1.3nm处 ,2 DEG分布峰的半高宽为 2 .3nm ,2 DEG面密度为 6 .5× 10 1 2 cm- 2 .与 Alx Ga1 - x As/ Ga As异质结相比 ,其 2 DEG面密度要高一个数量级 ,而空间分布则要窄一个数量级 .这主要归结于 Alx Ga1 - x N层中～ MV / cm量级的压电极化电场和自发极化电场对 Alx Ga1 - x N/ Ga N异质结能带的调制和 Alx Ga1 -     

RF-MBE生长AlN/GaN超晶格结构二维电子气材料

用射频等离子体辅助分子束外延技术( RF- MBE)在c面蓝宝石衬底上外延了高质量的Ga N膜以及Al N/Ga N超晶格结构极化感应二维电子气材料.所获得的掺Si的Ga N膜室温电子浓度为2 .2e1 8cm- 3,相应的电子迁移率为2 2 1cm2 /( V·s) ;1μm厚的Ga N外延膜的( 0 0 0 2 ) X射线衍射摇摆曲线半高宽( FWHM)为7′;极化感应产生的二维电子气室温电子迁移率达到10 86cm2 /( V·s) ,相应的二维电子气面密度为7.5e1 2 cm- 2 .     

采用ALD Al2O3作为栅介质的薄势垒增强型AlGaN/GaN MIS-HEMT

本文报道了高性能的增强型（E-mode）氮化镓（GaN）基金属-绝缘体-半导体高电子迁移率晶体管（MIS-HEMT）,该器件势垒层为5-nm厚的铝镓氮（Al0.3Ga0.7N）,并采用氮化硅（SiN）钝化来控制二维电子气（2DEG）密度。与SiN钝化不同,采用原子层淀积（ALD）技术生长的氧化铝（Al2O3）不会增强异质结中的2DEG密度。刻蚀栅区的SiN介质可以耗尽沟道电子,之后采用ALD Al2O3作为栅介质,可以实现MIS结构。栅长为1 μm的E-mode MIS-HEMT具有657mA/mm的最大饱和电流（IDS）、187mS/mm的最大跨导（gm）和1V的阈值电压（Vth）。与相应的E-mode HEMT对比,由于Al2O3栅介质的引入,使器件的性能得到了很大的提升。本文对于同时实现高的Vth和IDS提供了很好的方法。     

In_(0.5)Ga_(0.5)P/GaAs二维空穴气p沟异质结场效应管

提出了一种新颖的 Ga As基 p沟异质结场效应管 (p HFET)概念 ,器件采用了 In0 .5Ga0 .5P/ Ga As异质系统及二维空穴气 (2 DHG)原理以改善 Ga As的空穴输运特性。据此原理研制的器件可在室温下工作 ,其实验结果为 :室温下 ,饱和电流 Idss=6 1m A/ mm,跨导 gm=4 1m S/ mm;77K下 ,饱和电流 Idss=94 m A/ mm,跨导 gm=6 1m S/ mm。预计该器件在微波和数字电路中极佳的电流密度及高频增益 ,因而具有良好的应用潜力。     

肖特基C-V法研究AlxGa1-xN/GaN异质结界面二维电子气

通过对Pt/AI0 22Ga078N/GaN肖特基二极管的C-V测量,研究分析了A1022Ga078N/GaN异质结界面二维电子气(2DEG)浓度及其空间分布.测量结果表明,Al0.22Ga.8N/GaN异质结界面2DEG浓度峰值对应的深度在界面以下1.3nm处,2DEG分布峰的半高宽为2.3nm,2DEG面密度为6.5×1012cm-2.与AlxGa1xAs/GaAs异质结比,其2DEG面密度要高一个数量级,而空间分布则要窄一个数量级.这主要归结于A1xGa1-xN层中～MV/cm量级的压电极化电场和自发极化电场对AlxGa1-xN/GaN异质结能带的调制和AlxGa1xN/GaN异质结界面有更大的导带不连续.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first