半导体材料研究的新进展（续）

光学微腔是指具有高品质因子而尺寸与谐振光波长（1）相比拟的光学微型谐振器。随着MBE、MOCVD生长技术和现代微细加工技术发展，设计、制造有实用价值的光学微腔已成为可能，关在低（无）阈值激光器研制方面取得了很大进展。大家知道，当光腔尺度与光波长可比拟时，腔内真空场的光学模式数则大大减小（1个光学模式占有相当于(λ／2n)~3大小体积，n为介质有效折射率)。在理想情况下，若用一个边长为半波长，周界为全反射壁的立方微腔，有可能将一个单模光场分离出来，这为实现低（无）阈值激光器的研制提供了科学依据。

立方相 Al_xGa_(1-x)N/GaAs(100)的MOVCD外延生长

利用MOCVD生长技术在GaAs(100)衬底上生长了高质量的立方相AlGaN薄膜。通过光致发光（PL）、扫描电镜（SEM）分析了不同NH_3流量、不同生长温度对AlGaN外延层的结晶质量和表面形貌的影响。发现相对高的NH_3流量和相对高的生长温度可以提高AlGaN外延层的结晶质量。

Metalorganic Chemical Vapor Deposition of GaNAs Alloy Using Dimethylhydrazine as Nitrogen Precursor

GaNAs alloy is grown by metalorganic chemical vapor deposition (MOCVD) using dimethylhydrazine (DMHy) as the nitrogen precursor. High-resolution X-ray diffraction (HRXRD) and secondary ion mass spectrometry (SIMS) are combined in determining the nitrogen contents in the samples. Room temperature photoluminescence (RTPL) measurement is also used in characterizing. The influence of different Ga precursors on GaNAs quality is investigated. Samples grown with triethylgallium (TEGa) have better qualities and less impurity contamination than those with trimethylgallium (TMGa). Nitrogen content of 5.688% is achieved with TEGa. The peak wavelength in RTPL measurement is measured to be 1278.5nm.

MOVPE生长的GaN基蓝色与绿色LED

报道用自行研制的LP-MOVPE设备,在蓝宝石(α-Al_2O_3)衬底上生长出以InGaN为有源区的蓝光和绿光InGaN/AlGaN双异质结构以及InGaN/GaN量子阱结构的LED,其发射波长分别为430～450nm和520～540nm。

InGaAs/GaAs多量子阱SEED设计和特性研究

分析计算了InGaAs/GaAs多量子阱(SEED)的激子吸收行为,对器件的多量子阱及谐振腔结构进行了设计和理论分析, 用MOCVD系统生长了多量子阱外延材料,并且对器件的反射谱和光电流谱特性进行了测试。

选择区域生长高质量InGaAsP多量子阱材料

采用LP-MOVPE在SiO_2掩膜的InP衬底上实现了高质量的InGaAsP多量子阱(MQW)的选择区域生长(SAG)。通过改变生长温度和生长压力，MQW的适用范围由C波段扩展至L波段，即MQW的光致发光波长从1546nm延展至1621nm。光致发光(PL)测试表明

InGaAs/GaAs多量子阱 SEED面阵结构特性与设计（英文）

讨论了谐振腔中的DBR对InGaAs/GaAs多量子阱SEED面阵光反射特性的影响。采用InGaAs/GaAs作为多量子阱SEED器件的有源区，从而获得了980nm工作波长。设计和分析了InGaAs/GaAs多量子阱SEED中的一种用于倒装焊的新型谐振腔结构。多量子阱材料是用MOCVD系统生长，利用微区光反射谱、PL谱以及X射线双晶衍射对多量子阱材料进行了测量和分析，测量结果表明多量子阱材料具有良好的质量，证明了器件结构的设计和分析是准确的。

InGaN/AlGaN双异质结绿光发光二极管

报道了用LP-MOVPE技术在蓝宝石(α-Al_2O_3)衬底上生长出以双掺Zn和Si的InGaN为有源区的绿光InGaN/AlGaN双异质结结构，并研制成功发射波长为520-540nm的绿光LED。

Au-GaN肖特基结的伏安特性

在MBE和MOCVD两种方法制备的n-GaN材料上制作了Au-GaN肖特基结，测定了肖特基结的室温I-V特性。分析表明

表面电场导致InGaAs/GaAs量子阱子带跃迁选择定则的改变

报道用MOCVD方法制作高质量的InGaAs/GaAs应变量子阱材料.单量子阱样品在室温光伏谱中出现清晰的11H、12H、21H和22H激子吸收峰.首次用室温光伏方法研究表面自建电场导致InGaAs/GaAs量子阱中子带间跃迁选择定则的改变.

优化生长的In_xGa_(1-x)As缓冲层上双势垒In_yGa_(1-y)As/Al_zGa_(1-z)As/GaAs/Al_zGa_(1-z)As多量子阱应变状态测量

一种多步生长方法应用于GaAs衬底上的In_xGa_(1-x)As缓冲层的MOCVD生长.在这种In_xGa_(1-x)As缓冲层上生长的In_yGa_(1-y)As/Al_zGa_(1-z)As/GaAs/Al_zGa_(1-x)As双垫垒量子阱材料表现出了很好的晶格特性和光学性质.超晶格的室温光伏谱中出现很强的22H高阶机制吸收峰,表明超晶格界面质量很好.主要应用X射线双晶衍射方法,给出了样品中各层的应变状态.据此,合理地解释了样品的光学测试结果.

高精度双晶衍射（HRDCD）方法检测InGaAs/GaAs超薄应变层量子阱结构参数

应变超薄层结构的组分、厚度应变状态的直接检测,对于器件应用具有重要的意义,该文中,利用MOCVD方法得到高质量的InGaAs/GaAs量子阱材料,采用双晶衍射方法的弱信号收集技术,结合运动学理论模拟,得出同时包含几个不同阱宽的InGaAs/GaAs量子阱结构的重要参数,其检测结果与光致发光(PL)、透射电子显微镜(TEM)等方法的测试结果基本一致,表明X射线双晶衍射方法是检测超薄层应变量子阱结构的一个有效方法。

低压-金属有机物汽相外延生长的Ga（1-x）InxAs/InP激光器中深能级的研究

应用深能级瞬态谱(DLTS)技术详细研究低压-金属有机物汽相外延(LP-MOVPE)生长的Ga_(0.74)In_(0.53)As/InP量子阱、宽接触和质子轰击条形异质结激光器中的深能级。样品的DLTS表明,在宽接触激光器的i-Ga_(0.47)In(0.53)As有源层里观察到 H1(Ev+0.09eV)和E1(E_c-0.35eV)陷阱,它们可能分别与样品生长过程中扩散到i-Ga_(0.47)In_(0.53)As有源层的Zn和材料本身的原生缺陷有关。而条形激光器的i-Ga_(0.47)In_(0.53)A_s有源层的 H_2(E_v+0.11eV)和 E_2(E_q-0.42eV)陷阱则可能是H1和E1与质子轰击引起的损伤相互作用的产物 。

Growth and photoluminescence of InAlGaN films

Two quaternary InAlGaN films were grown by metal-organic chemical-vapor deposition (MOCVD) on sapphire (0001) substrates with and without high-temperature GaN interlayer, respectively. The structural and optical properties of the quaternary films were investigated by high-resolution X-ray diffraction (HRXRD), high-resolution electron microscopy (HREM), temperature-dependent photoluminescence (PL) spectroscopy and time-resolved photoluminescence (TRPL) spectroscopy. According to the HRXRD and PL results, it is demonstrated that two samples have the same crystal quality. The TRPL signals of both samples were fitted well as a stretched exponential decay from 14 K to 250 K, indicating significant disorder in the materials, which is attributed to recombination of excitons localized in disorder quantum nanostructures such as quantum dots or quantum disks originating from indium (In) clusters or In composition fluctuation. The cross-section HREM measurement further proves that there exist disorder quantum nanostructures in the quaternary. By investigating the temperature dependence of the dispersive exponent beta, it is shown that the stretched exponential decays of the two samples originate from different mechanisms. (C) 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fabrication of 1.3 mu m Si-based MEMS tunable optical filter

In this paper we report the fabrication of 1.3 mum Si-based MEMS tunable optical filter, by surface micromaching. Through wet etching of polyimide sacrificial layer, a tunable Fabry-Perot filter was successfully fabricated. We make the capacitance measurement of the prototype device, compare the experimental curve with the theoretical one, and explain the difference between them.