MBE生长中缓冲层对InSb/GaAs质量影响的研究

用分子束外延(MBE)方法在GaAs(001)衬底上外延生长了InSb薄膜,并研究了异质外延InSb薄膜生长中缓冲层对材料质量的影响.采用原子力显微镜(AFM)、透射电子显微镜(TEM)、X射线双晶衍射(DCXRD)等方法研究了InSb/GaAs薄膜的表面形貌、界面特性以及结晶质量.通过生长合适厚度的缓冲层,获得了室温下DCXRD半高峰宽为272",迁移率为64 300 cm2V-1s-1的InSb外延层.     

GaAs超薄层腐蚀与非线性光学器件制作

用液相外延生长与H_2O_2选择腐蚀制备了GaAs—GaAlAs非线性光学器件。研究了H_2SO_4:H_2O_2:H_2O腐蚀液的快速腐蚀和H_2O_2—NH_3·H_2O的GaAs选择腐蚀过程。适宜pH值的H_2O_2腐蚀液对GaAs具有～1μm/小时的腐蚀速度,而对Ga_1-xAlxAs(x≥0.25)不产生腐蚀。分析和讨论了腐蚀过程和速择腐蚀机理。     

利用全固态分子束外延方法在Ge(100)衬底上异质外延GaAs薄膜及相关特性表征

利用全固态分子束外延(MBE)方法在Ge(100)衬底上异质外延GaAs薄膜,并通过高能电子衍射(RHEED)、高分辨X射线衍射(XRD),原子力显微镜等手段研究了不同生长参数对外延层的影响.RHEED显示在较高的生长温度或较低的生长速率下,低温GaAs成核层呈现层状生长模式.同时降低生长温度和生长速率会使GaAs薄膜的XRD摇摆曲线半高宽(FWHM)减小,并降低外延层表面的粗糙度,这主要是由于衬底和外延薄膜之间的晶格失配度减小的结果.     

在MBE生长的SI—GaAs衬底上单片集成AlGaAs/GaAs多量子阱激光器和GaAs金属—半导体场效应晶体理

近年来,在同一衬底上单片集成光电子器件的研究相当活跃,现已报导的一些光电子集成电路(OEIC),大多采用液相外延(LPE)生长多层结构。日本富士通的T.Sanade等人报导了在MBE生长的SI—GaAs衬底上的AlGaAs/GaAs多量子阱(MQW)LD和GaAsMESFET的单片集成。由MQW激光器和两只MESFET组成的集成结构如图1所示。所有外延层均用MBE法在(100)SI—GaAs衬底上生长。MBE生长分别进行三次,即n~+-GaAs接触层,激光器结构和FET层。生长激光器结构时,衬底温度为710℃。沟槽腐蚀后,先在SI—GaAs衬底上生     

GaAs表面处理及其椭圆偏振仪、俄歇电子能谱与X-光电子谱的特性测定

用椭圆偏振仪、俄歇电子能谱仪(AES)和X-光电子谱仪(XPS)等对经pH=7±0.05的H_2O_2-NH_40H溶液化学腐蚀或用NH_4OH:H_20=1:10和HCl:H_2O=1:1进行清洗后的GaAs表面残余氧化层厚度、折射率、纵向组分分布和Ga(3d)与As(3d)结合能变化等进行测定.三者实验结果对应很好.化学腐蚀后的GaAs表面有一层氧化物层,然后是氧化物与GaAs混合的过渡层,直至GaAs衬底.从NH_4OH:H_2O=1:10清洗后GaAs表面残余氧化层厚度,表面C吸附量和Ga/As的波动看,它均比用HCl:H_2O=1:1清洗为优,故用它作为GaAs在化学腐蚀后的清洗是可取的.     

基于金属背支撑刻蚀技术的柔性AlGaInP/AlGaAs/GaAs三结太阳电池研制

对柔性GaAs基太阳电池的制备方法进行研究,报道了一种用于制备柔性倒置生长的AlGaInP/AlGaAs/GaAs三结太阳电池的剥离和转移方法——金属背支撑选择性湿法刻蚀技术.在GaAs/GaInP选择性腐蚀的基础上进行了GaAs衬底层的腐蚀,研究了不同类型和体积比的溶液对GaAs/GaInP/AlInP结构腐蚀的选择特性,最终选用不同配比的H2 SO4-H2 O2系腐蚀液,获得快速、可控制、重复性好的去除衬底的两步腐蚀法.原子力显微镜测试结果表明,通过此方法能够成功地将电池外延层薄膜转移到Cu衬底上,并且在剥离和转移过程中外延层薄膜没有受到损伤.柔性AlGaInP/AlGaAs/GaAs三结太阳电池的开路电压超过3.4V.     

MBE生长GaAs/AlGaAs量子阱材料结构及其光学性能研究

系统研究了Ⅰ类组分量子阱结构材料GaAs/AlGaAs的结构设计、材料表征及光学性能.利用分子束外延(MBE)技术生长量子阱材料,原子力显微镜(AFM)测量结果表明样品表面粗糙度达到10-1 nm数量级.X射线双晶衍射测试结果显示材料具备良好的生长质量及晶格完整性.室温光致发光谱探测出量子阱导带电子与价带轻重空穴的复合发光,及施主-受主(D-A)能级间距与GaAs禁带宽度.综合分析结果表明用MBE方法制备实现了与设计结构高度相符的GaAs/Alo.27Gao.73As量子阱样品,为后期器件设计的精确实现提供了理论依据.     

在Si上集成GaAs LED

美国TI公司中央研究实验室研制成功一种在Si3位CMOS译码器上集成8只GaAs LED阵列.电源电压5V.Si衬底材料为P~-.该实验室采用了如下工艺:(1)先生长CMOS源和漏,然后通过SUi_2/Si_3N_4制作n~+Si,然后再在n~+Si飞上集成GaAs LED;(2)清洗工艺采用H_2SO_4-H_2O_2+2%HF;(3)用常规两步MDE方法生长1.5μmGaAs缓冲层.然后再生长GaAs双异质结LED外延层.     

用MBE制作ZnSe电流限制区的隐埋顶层平面条型(BCP)GaAlAs激光器

我们已经研制成功一种新型结构的GaAlAs可见光激光器,叫做隐埋顶层平面条型(BCP)激光器。这种激光器是用分子束外延(MBE),在复盖层上生长了一层外延ZnSe半绝缘层,并在其上留下一笮条区作为电流限制。图1是GaAlAs BCP激光器的结构示意图。其制作程序如下:在具有1.5μm深槽n型GaAs衬底上用一般的LPE生长了GaAlAs/GaAs DH结之后,第四层(P-GaAs,顶层)是通过SiO_2掩膜腐蚀成3—5μm的条宽的台面。然后,在用MBE晶片上外延一层与顶层同样厚的ZnSe半绝缘层。这种工艺能够在P型GaAlAs复盖层上生长出镜面的ZnSe     

原子氢辅助MBE生长的不同晶面GaAs表面形貌

研究了原子氢辅助分子束外延(MBE)中,原子氢对不同晶面GaAs外延层表面形貌特征的诱导作用.原子力显微镜(AFM)测试表明,在GaAs的(311)A和(331)A面,原子氢导致了台阶状形貌的形成.提出了一种简单模型,解释了台阶面形貌形成的物理机制.为最终有序低维纳米表面结构提供了一种实验参考.     

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