高纯VPE-GaAs、LPE-GaAs的电学性质

用Van der Pauw法测量高纯VPE-GaAs和LPE-GaAs样品在20—300K温度范围内的电学性质,分析了它们的电子散射机理.最纯的VPE-GaAs样品峰值迁移率高达3.76×10~5cm~2/V·s,LPE-GaAs样品的峰值迁移率为2.54×10~5Cm~3/V·s.这两个样品的总离化杂质浓度分别为 7.7 × 10~(13)cm~(-3)和 1.55 ×10~(14)cm~(-3).     

7μmGaAs／AlGaAs多量子阱红外探测器

利用GaAs(51(?))/Al_(0.36)Ga_(0.64)As(200(?))多量子阱结构实现了黑体辐射的探测,探测器的峰值波长为7μm,77K温度下D~*达到1.09×10~9cm·Hz~(1/2)·W~(-1),电压响应率为2.5×10~4V·W~(-1).     

四硼酸锂单晶的热电和压电性能

在50—-150℃的温度范围内测量了Li_2B_4O_7(LTB)单晶的热电、压电和介电性能.室温时,LTB的介电常数K_3约为10(100kHz),介电tgδ约为1(10kHz),液氮温度下,tgδ降到～10~(-3),室温时测得的热电系数约为-30μC/m~2·K,而当温度为-150℃时,热电系数增至-120μC/m~2·K,并显示出能与室温下获得的TGS的值相媲美的热电品质因素p/K值,测量结果表明,Li_2B_4O_7的一次和二次热电分量为独立分量,其一次效应对热电效应起主要作用.压电测量表明,Li_2B_4O_7的g_(33)值((?)270×10~(-3)V·m/N)和g_h值((?)100×10~(-3)V·m/N)大,预示着Li_2B_4O_7在压力传感器领域的应用前景.     

激光再结晶和氢退火对多晶硅电学性质的影响

连续Ar~+激光再结晶能使多晶硅的电阻率下降,迁移率显著增高,对离子注入剂量为5×10~(11)—5×10~(15)cm~(-2)的多晶硅经激光再结晶后再进行等离子氢退火,能使其电学性质得到进一步改善,更接近于单晶硅.掺杂浓度为1×10~(17)cm~(-3)时,电阻率从1.2Ω·cm下降到0.45Ω·cm,迁移率从 62cm~2/V·s增高到 271cm~2/V·s,电激活能从 0.03eV下降到-0.007eV,晶界陷阱态密度从3.7×10~(11)cm~(-2)下降到 1.7×10~(11)cm~(-2)。本文在现有多晶硅导电模型的基础上.提出了大晶粒(L=15μm)多晶硅的计算公式。结果表明,在掺杂浓度在1×10~(16)—1×10~(20)cm~(-3)的范围内,理论和实验符合较好。     

水平法生长GaSb单晶的研究

本文采用独特的工艺和装置,用水平法研制GaSb单晶.已获得不掺杂p型晶体,室温下其载流子浓度和迁移率分别为1.0～1.7×10~(17)cm~(-3)和630～780cm~2/V·s;渗Te的n型单晶两者分别为1.4×10~(18)cm~(-3)和2690cm~2/V·s,成晶率大于50%.本文还探讨了研制过程中存在的几个问题.     

分子束外延高性能P型GaAs单晶薄膜

用国产分子束外延设备生长出性能优良、表面平整光洁的GaAs。不掺杂的P型GaAs空穴浓度为 2-8×10~(14)cm~(-3),室温迁移率为360-400cm~2/V·s.使用国产材料,纯度为 2N5并经我们“提纯”的 Be作为 P型掺杂剂.掺 Be的 P型GaAs空穴浓度范围从1.0 × 10~(15)至6×10~(15)cm~(-3).其室温迁移率与空穴浓度的关系曲线与国外文献的经验曲线相符.当空穴浓度为1—2 ×10~(15)cm~(-3)时,室温迁移率达 400cm~2/V·s.低温(77K)迁移率为 3500—7000cm~2/V·s.在4.2K下对不同空穴浓度的P型GaAs样品进行了光荣光测量和分析.     

液相外延HgCdTe的研究

本文对液相外延生长HgCdTe及其汞压控制进行了研究。在理论上对开管滑动系统中汞损失的影响作了分析和计算,提出了准平衡汞压的方法。在实验中设计制作了独特的汞回流装置,实现了对汞压的控制。通过生长工艺的条件实验,得到了各工艺参数影响外延片性能的关系,制备出表面光亮,组分为x=0.211±0.002,x=0.28±0.001的Hg_(1-x)Cd_xTe外延片。在77°K下n型(未退火)和P型外延片的迁移率分别为3.36×10~3cm~2/V·s和1.81×10~3cm~2/V·s,载流子浓度分别为1.09×10~(15)cm~(-3)和1.04×10~(16)cm~(-3)。     

一种汽相外延Ga_xIn_(1-x)As的技术

本文描述了一种汽相外延Ga_xIn_(1-x)As的技术:在AsCl_3/Ga/In/H_2体系中,采用Ga/In合金源汽相生长Ga_xIn_1As。该方法具有外延层组分重复可控、均匀性好的特点;且易于获得高纯外延Ga_xIn_(1-xAs层。外延Ga_(0.47)In_(0.53)As电学参数最佳值已达:n300K=1.2×10~(15)cm~(-3),μ300K=9580cm~2/V·s;n77K=1.1×10~(15)cm~(-3),μ77K=3.82×10~4cm~2/V·s。     

三分量全保偏光纤加速度传感器的研究

报道了三分量全保偏光纤加速度传感器的实验研究结果。传感器由6个弹性柱体共同支撑1个质量块构成三分量结构,由3个迈克尔逊全保偏光纤干涉仪共用一个光源组成。光学部分采用全保偏光纤干涉仪结构,消除了干涉光束偏振态随机变化引起的信号衰落,采用光频调制相位载波解调信号处理技术,消除了相位随机漂移引起的信号衰落,从而实现了对加速度信号的稳定检测。传感器的工作频带为5~500 Hz,加速度灵敏度达到660 rad/g,系统最小可测相位差为10-5rad,最小可测加速度达1.5×10-7m/s2,工作频带内加速度灵敏度变化小于2 dB。三轴加速度灵敏度和频率响应曲线与理论分析的结果基本一致。     

压电石英晶体线加速度计

加速度计是惯性制导和惯性导航等应用中重要的传感器之一,其原理和结构多种多样.本文详细介绍了新近研制的悬臂梁式压电石英晶体线加速度传感器.实验表明:分辨率优于10~(-2)m/s~2,非线性度低于1%,测量上限可达1000m/s~2.     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

Complete approach to automatic identification and sub-pixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

A Versatile Mixed-Signal Pin Approach for Cost-Effective Test of Automotive ICs

Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V.     

Optical vibration and deviation measurement of rotating machine parts

It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer （LDV）.     

社长序言（英文）

正Happy New Year!As we step into a new year,we take a look back at the key feature topics covered in China Communications over the past 12 months and set out our expecta-     

Call for Papers

正Introduction Jointly sponsored by the China Institute of Communications(CIC)and the IEEE Communications Society(IEEE ComSoc)since the year 2013,China Communications,currently,is aiming to gradually realise the transition from journal to magazine content and style.     

INTEGRATION OF OPTICAL AND WIRELESS NETWORKS

正For a long time,optical and wireless systems/net-works are developed in separate communities witha few attempts for in-depth convergence.In fact,it prom-ises many advantages to combine the optical and wire-less technologies in the levels of systems and networks.Recently,both academia and industry have made manyefforts to enter a new phase of development to take op-tical and wireless systems as fully integrated networks.To provide high bandwidth and reliable service for bothfixed and mobile users,a well-designed network must     

Call for Papers—Feature Topic,Vol.12,No.3,2015

正Smart Grid Communications The electric power industry is undergoing profound changes as the industry aims to capture the promise of a smart grid for a sustainable energy future.Enabled by the advanced sensing devices such as Phasor Measurement Units(PMUs),increasingly powerful