As/P气氛转换对InGaAs/InP异质结界面的影响研究

采用分子束外延(MBE)方法,在半绝缘InP(100)衬底上外延InGaAs/InP超晶格结构。通过优化As、P转换时间,研究了As、P气氛转换对InGaAs/InP异质结界面特性的影响。经原子力显微镜测试和X射线衍射谱分析,样品在关P阀5 s、开As阀5 s的生长条件下,表面均方根粗糙度(RMS)为0.205 nm,单边卫星峰达20级,一级卫星峰的半高宽(FWHM)为145.05 arc sec,表明界面控制良好。     

InGaAs/InP材料的MOCVD生长研究

研究了InGaAs/InP材料的MOCVD生长技术和材料的性能特征。InP衬底的晶向偏角能够明显影响外延生长模型以及外延层的表面形貌,用原子力显微镜(AFM)观察到了外延层表面原子台阶的聚集现象(step-bunching现象),通过晶体表面的原子台阶密度和二维生长模型解释了台阶聚集现象的形成。对外延材料进行化学腐蚀,通过双晶X射线衍射(DCXRD)分析发现异质结界面存在应力,用异质结界面岛状InAs富集解释了应力的产生。通过严格控制InGaAs材料的晶格匹配,并优化MOCVD外延生长工艺,制备出厚层InGaAs外延材料,获得了低于1×1015cm-3的背景载流子浓度和良好的晶体质量。     

MOCVD生长InGaAs/InP体材料研究

首先给出在InP衬底上利用MOCVD法生长InP、InGaAs的生长条件，而后分别给出了InP／InP的生长特性，InGaAs／InP的组份控制和生长特性及生长温度对InGaAs特性的影响。     

太赫兹InP基InAlAs/InGaAs PHEMTs的研制

研制了一种T型栅长为90 nm的InP基In0.52Al0.48As/In0.65Ga0.35As赝配高电子迁移率晶体管(PHEMTs).该器件的总栅宽为2×25 μm,展现了极好的DC直流和RF射频特性,其最大饱和电流密度和最大有效跨导分别为894 mA/mm和1640 mS/mm.采用LRM+ (Line-Reflect-Reflect -Match)校准方法实现系统在1~110 GHz全频段内一次性校准,减小了传统的分段测试多次校准带来的误差, 且测试数据的连续性较好.在国内完成了器件的1~110 GHz全频段在片测试,基于1~110 GHz在片测试的S参数外推获得的截止频率ft和最大振荡频率fmax分别为252 GHz和394 GHz.与传统的测试到40 GHz外推相比,本文外推获得的fmax更加准确.这些结果的获得是由于栅长的缩短,寄生效应的减小以及1~110 GHz全频段在片测试的实现.器件的欧姆接触电阻率减小为0.035 Ω·mm.     

一种InGaAs/InP复合沟道高电子迁移率晶体管模拟的新方法

采用一种新方法对InGaAs/InP复合沟道高电子迁移率晶体管进行了模拟.该方法通过流体力学模型和密度梯度模型的联合求解,得到了沟道内的电子密度分布.与一些传统方法相比,该方法收敛性更好,速度更快,且同样适用于其他类型高电子迁移率晶体管器件的模拟.利用仿真对InGaAs/InP复合沟道高电子迁移率晶体管进行了深入研究.     

InP/InGaAs探测器对伪装目标成像研究

高性能InP/InGaAs宽光谱探测器将前截止波长延伸到0.9μm之前,实现可见/短波双波段探测,大大丰富了探测目标的信息量,提高对目标的识别率.本文采用InP/InGaAs宽光谱探测器相机,通过设置一系列伪装实验,对比不同伪装目标的可见光波图像与短波红外图像的差异,重点探究短波红外对伪装目标的识别特性.通过实验结果发现:短波红外对一定厚度塑料、硅胶、皮肤具有穿透性;颜料、染料等同色不同材质的物体对短波红外具有选择性吸收,基于以上特性,短波红外体现了较好的伪装识别效果.在成像对比实验的基础上,进一步选择伪装效果对可见光和短波红外具有明显差异的实验样品,分别测量了它们对短波红外和可见光的反射率等参数,以深入地分析和理解短波红外识别伪装的机理.     

一种InGaAs/InP复合沟道高电子迁移率晶体管模拟的新方法

采用一种新方法对InGaAs/InP复合沟道高电子迁移率晶体管进行了模拟.该方法通过流体力学模型和密度梯度模型的联合求解,得到了沟道内的电子密度分布.与一些传统方法相比,该方法收敛性更好,速度更快,且同样适用于其他类型高电子迁移率晶体管器件的模拟.利用仿真对InGaAs/InP复合沟道高电子迁移率晶体管进行了深入研究.     

ZnO/PS异质结的光学和电学性质

用脉冲激光沉积的方法在多孔硅(PS)衬底上沉积ZnO薄膜,在室温下测量了ZnO/PS异质结的结构及光学和电学性质.X射线衍射仪和扫描电子显微镜测量表明,制备的ZnO薄膜具有一定的c轴取向,但薄膜存在较多缺陷.光致发光谱显示,PS的发光与ZnO的发光相叠加,呈现白光发射.对异质结I-V特性曲线的测量表明,异质结呈现出与普通二极管不同的整流特性,其反向电流不饱和,据此提出了能带模型.     

栅长90nm的晶格匹配InAlAs／InGaAs／InP HEMT

文章报道了90nm栅长的晶格匹配InP基HEMT器件。栅图形是通过80kV的电子束直写的,并采用了优化的三层胶工艺。器件做在匹配的InAlAs／InGaAs／InP HEMT材料上。当Vds=1．0V时,两指75μm栅宽器件的本征峰值跨导达到720ms／mm,最大电流密度为500mA／mm,器件的阂值电压为．0．8V,截止频率达到127GHz,最大振荡频率达到152GHz。     

高速InP/InGaAs雪崩光电二极管

采用分层吸收渐变电荷倍增(SAGCM)结构,通过两次扩散、多层介质淀积、AuZn p型欧姆接触、AuGeNi n型欧姆接触等工艺,设计制造了正面入射平面InP/InGaAs雪崩光电二极管,器件利用InGaAs做吸收层,InP做增益层,光敏面直径50 μm;测试结果表明器件有正常的光响应特性,击穿电压32～42 V,在低于击穿电压2 V左右可以得到大约10A/W的光响应度,在0到小于击穿电压1 V的偏压范围内,暗电流只有1 nA左右;器件在2.7 GHz以下有平坦的增益.     

Investigations on the interface abruptness in CBE-grown InGaAs/InP QW structures

In this work we present a detailed analysis of chemical beam epitaxy-grown (CBE) InGaAs/InP multi quantum well (MQW) interfaces to explain experimental data from high quality single and multi-QWs. Our results compare well with the best published data we have obtained some outstanding results. For example, the very intense absorption peak and the high number of satellite peaks in the diffraction rocking curve, were obtained even on samples grown in non-optimized conditions. A careful use of growth interruption at the interfaces allows us to obtain monolayer (ml) interfaces. Nevertheless, the switching of the group V element at each interface leads to strain formation. This effect could become dramatic in superlattice structures with periods smaller than about 5 nm and barriers of less than 3–4 nm. More generally, the conditions for the growth of high quality single and multiple QWs is discussed in this work and these will be correlated with fourier transform photoluminesence (FTPL), high resolution x-ray diffraction (HRXRD), absorption, photo-absorption and photo-current (in PIN structures) measurements.     

Optical properties of Zn-diffused InP layers for the planar-type InGaAs/InP photodetectors

Zn diffusion into InP was carried out ex-situ using a new Zn diffusion technique with zinc phosphorus particles placed around InP materials as zinc source in a semi-closed chamber formed by a modified diffusion furnace.The optical characteristics of the Zn-diffused InP layer for the planar-type InGaAs/InP PIN photodetectors grown by molecular beam epitaxy (MBE) has been investigated by photoluminescence (PL) measurements.The temperature-dependent PL spectrum of Zn-diffused InP samples at different diffusion temperatures showed that band-to-acceptor transition dominates the PL emission,which indicates that Zn was commendably diffused into InP layer as the acceptor.High quality Zn-diffused InP layer with typically smooth surface was obtained at 580 ℃ for 10 min.Furthermore,more interstitial Zn atoms were activated to act as acceptors after a rapid annealing process.Based on the above Zn-diffusion technique,a 50μm planar-type InGaAs/InP PIN photodector device was fabricated and exhibited a low dark current of 7.73 pA under a reverse bias potential of-5 V and a high breakdown voltage of larger than 41 V (I ＜ 10 μA).In addition,a high responsivity of 0.81 A/W at 1.31 μm and 0.97 A/W at 1.55 μm was obtained in the developed PIN photodetector.     

Strain from modified interface compositions in InGaAs/InP superlattices

Thin strained regions have been inserted at the interfaces of lattice-matched InGaAs/lnP superlattices to assess growth conditions for tailoring of localized compositional changes and for studying As-P intermixing behavior during heterojunction growth. Also, precise growth rates of binary composition layers were determined from specially designed superlattices using strained layers of common anion compounds inserted periodically into InP and GaAs. Growth rates of fractional monolayers are found to be identical to thick layer growth rates. When thin InAs, GaAs, GaP, ALAs, or AIP layers were inserted at the InGaAs/lnP heterojunctions, the measured strain at either one or both interfaces was equal to the strain predicted from the growth rate x time product. Excess strain seen in some cases is due to a change in As-P intermixing and this component can be separated from the predicted strain. Insertion of Ga-compounds at the InP-grown-on-InGaAs interface causes interface roughening which degrades the superlattice. For all other compositions the thin, highly strained regions are not detrimental to the crystalline quality of the periodic structure.     

单片InGaAs／InP PIN PD阵列

文章简要地介绍了ＩｎＧａＡｓ／ＩｎＰ ＰＩＮ ＰＤ阵列的制作现状及其应用和发展趋势。     

InP/InGaAs探测器氮化硅钝化膜的ICPCVD生长技术

采用ICPCVD工艺对InP/InGaAs探测器进行SiNx薄膜钝化,讨论了不同气体比例、射频功率和反应压力对SiNx薄膜应力和致密性的影响.初步得到了低应力、良好致密性的SiNx薄膜沉积工艺.利用此工艺制作的InP/InGaAs探测器在偏压为-10 mV的暗电流比PECVD工艺制作的器件降低了一个数量级,为4.4×10-8 A.     

p-i-n InP/InGaAs光电探测器电流及电容特性研究

为了实现高灵敏度探测,红外探测器需要得到优化。利用Silvaco器件仿真工具研究了p-i-n型InP/In_0.53Ga_0.47As/In_0.53Ga_0.47As光电探测器结构,模拟了结构中吸收层浓度和台阶宽度对暗电流及结电容的影响。结果表明,随着吸收层掺杂浓度的逐渐增大,器件暗电流逐渐减小,结电容逐渐增大;当台阶宽度变窄时,器件暗电流随之减小,结电容也随之变小。最后研究了光强和频率对器件结电容的影响：在低光强下,器件结电容基本不变;当光强增大到1 W/cm²时,器件结电容迅速增大;器件结电容随频率的升高而减小,其峰值由缺陷能级引起。     

基于Cl2基气体的InP/InGaAs干法刻蚀研究

对于用Cl2/Ar和Cl2/CH4/H2感应耦合等离子体(ICP)刻蚀InP/InGaAs多层膜进行了研究.发现用Cl2/Ar刻蚀InP/InGaAS时InP侧壁内切,在InP和lnGaAs界面存在侧壁不连续问题.而用Cl2/CH4/H2刻蚀时,两层侧壁是平整连续的,且刻蚀区表面的粗糙度也比较小.分析了两种气体组合的刻蚀机理,对上述实验现象给出了解释.