化学束外延（CBE）的研究现状及其应用

化学速外延(CBE)是近三,四年才发展起来的一种新的外延生长技术,本文较系统地评述了CBE的研究现状,并在把CBE技术与MOCVD和MBE技术比较的基础上,着重介绍了CBE的原理和特点,最后介绍了它在制备化合物半导体薄膜和光电器件方面的和最新进展.     

化学束外延介绍

化学束外廷(Chemical Beam Epitaxy,简称CBE)是一种由分子束外延(MBE)和金属有机物化学汽相淀积(MOCVD)发展而来的新技术,它结合了MBE的束的属性和MOCVD的控制和采用全汽相源的特点,它综合了两者的优点而使各自的缺点得到弥补。最近用化学束外延得到的结果表明CBE具有超过MBE和MOCVD的潜力而成为一种非常重要的新的外延技术。本文主要通过与MBE和MOCVD的对比,对CBE作了简单的介绍。     

CBE设备的控制系统

化学束外延(CBE)是半导体超薄层材料生长技术的最新发展,它兼有MBE和MOCVD两者的优点。我们研制出了CBE设备。本文给出了CBE设备的控制系统的硬、软件设计。     

基于任务驱动和CBE相融合的教学模式可行性研究

任务驱动教学模式和CBE教学模式已被运用在一些课程教学中,并取得了一定的效果。从理论上分析任务驱动教学模式和CBE教学模式的内涵,探索基于任务驱动和CBE相融合的教学模式在《单元电气控制电路》课程中应用的可行性。     

国内首台化学束外延(CBE)系统的设计考虑及外延结果

研制了国内首台化学束外延(CBE)系统。半导体所用此系统进行了CBE实验,获得质量良好的半导体材料。本文给出该系统的设计考虑及CBE实验结果。     

化学束外延及其在半导体材料与器件中的应用

本文介绍了薄膜晶体生长的最新技术--化学束外延(CBE),通过与分子束外延(MBE)和金属有机化学汽相沉积(MOCVD)技术的比较,说明了这一新技术的基本概念,生长动力学以及在半导体材料和激光器件方面的应用.     

CBE模式在士官职业教育《电工基础》教学中的应用研究

CBE(Competency Based Education,以能力为基础的教育)教育模式强调以岗位所需职业能力的培养为核心,保证职业能力培养目标的实现,是士官职业教育中有效的教育模式之一。本文就CBE教育模式,结合士官职业教育中《电工基础》的教学改革,谈几点体会。     

光电子技术

TNZ 95050161化学束外延在光电子技术应用中的进展/周增析(中,国科学院半导体所)l]激光与红外一1995,25(4)’.一6~10 简要介绍了化学束外延(CBE)技术,综述了近年来CBE在光电子技术领域内取得的进展。图8(文) 研究T 1.06尸m和0.53尹m激光对硅pin光电二极管以及硅雪崩光电管的永久性损伤效应,测出了损伤闹值.实验发现,损伤闭值的大小与激光波长、脉冲宽度以及光电探测器结构有关.图4表泛参2(木)TNZ、95050162基子发光二极管阵列的光学中值滤波的实现/张建明,刘颖,刘福来,方志良,路明哲,母国光(南开大学现代光学所)lI红外与毫米波学报一1…     

MOCVD法生长HgCdTe薄膜晶体的发展趋势

本文综述MOCVD法生长HgCdTe薄膜晶体技术是生长超品格的需要,介绍了国内外的发展过程及本法的特点。目前在生长HgCdTe外延层方面存在的主要问题是外延层和衬底之间的互扩散和晶格失配。为此,在有机金属源、衬底外延工艺和生长方法上加以改进,因而发展成为:常压(标准)、低压、低温、光致、激光辅助MOCVD和化学束外延(CBE)等六种方法。     

基于CBE模式计算机基础课程教学研究

使用CBE模式对计算机基础课程进行教学,通过制定DACUM表对技能进行详细规范的考核。     

The role of brand community identification and reward on consumer brand engagement and brand loyalty in virtual brand communities

With the advent of interactive Web 2.0 (and beyond) technologies, the role of consumer brand engagement (CBE), which focuses on the consumer’s investment in their brand interactions, is of rapidly growing importance. Despite growing recognition of CBE’s importance in virtual brand communities, empirically-derived insight into its drivers, dynamics, and outcomes remains limited, as investigated in this study. Responding to this gap, we explore the effect of consumers’ brand community identification and reward on CBE, which we posit to subsequently affect brand loyalty. To investigate our hypotheses, we conducted a survey with 602 Facebook users. Our structural equation modeling results reveal brand community identification’s and reward’s positive effect on CBE, and a positive effect of CBE on brand loyalty. In addition, our findings reveal CBE’s partial mediating effect in the association of brand community identification and reward with brand loyalty. Theoretically, our findings further insight into CBE’s virtual community-based dynamics, with a focus on the role of community identification and reward. Practically, our results identify the key role of nurturing virtual community identification and the offering of reward to engage consumers.     

Chemical beam epitaxy

Chemical beam epitaxy (CBE), an offshoot of molecular-beam epitaxy (MBE) and metalorganic chemical vapor deposition (MO-CVD), is described. It combines the beam nature of MBE and the control and use of all-vapor source as in MO-CVD. The growth kinetics of all three processes are examined, and their advantages and disadvantages are considered. The monolayer thickness control capabilities of CBE are highlighted. Device applications of CBE are discussed     

基于认证的高效公钥加密算法

 2003年,Gentry提出基于认证的公钥加密方案.在基于认证的公钥加密方案中,第三方对认证申请者的公钥和/或身份进行签名,并将签名作为认证发送给申请者,申请者保存该认证作为解密时的部分私钥.接收方对密文解密需要同时拥有第三方对其公钥和/或身份的认证和接收方公钥对应的私钥,因此基于认证的加密方案同时具备基于身份加密方案的公钥可认证性和传统公钥方案中的私钥免撤销性.本文提出一种高效、紧凑的基于认证的公钥混合加密算法,新算法能在非随机预言机模型下被证明满足选择密文攻击安全.     

Selective area epitaxy and growth over patterned substrates by chemical beam epitaxy

Selective area epitaxy and growth over patterned substrate using chemical beam epitaxy (CBE) were investigated. Truly selective area epitaxy with no deposition over the SiO/sub 2/ masks has been routinely obtained with excellent epilayer morphology. Uniform coverage was obtained for regrowth over etched mesas to form buried heterostructures. For growth over etch channels, very unique growth characteristics were obtained. Buried crescent stripes similar to those formed by liquid-phase epitaxy inside channels were also obtained by CBE. These growth characteristics demonstrated the unique of CBE for diode laser fabrication.<>     

First hydride free GaInP/GaAs carbon doped HBT grown by CBE usingDMAAs and TBP

A current gain of 120, for a base sheet resistance of 400 Ω/□, is reported in a carbon doped base heterojunction bipolar transistor grown by chemical beam epitaxy (CBE) without hydride sources. This result is to the authors' knowledge, the best obtained with hydride free CBE for this device     

CBE2R: clustered-based energy efficient routing protocol for underwater wireless sensor network

Routing in undersea environment is one of the challenging research areas due to the nature of acoustic channel and underwater harsh environment. In underwater environment, the major challenges are propagation delay, high bit error rates, limited bandwidth, uncontrolled node mobility, water current, 3D deployment and limited resources. Hence, designing an efficient and communication protocols for underwater environment is a challenging issue. To control the node mobility and prolong the battery power of the nodes, we proposed Clustered-Based Energy Efficient Routing (CBE2R) protocol. CBE2R controls the node mobility and prolongs the battery power of nodes by dividing the water depth into seven numbers of layers from top to seabed. CBE2R prolongs the battery power through powerful static courier nodes which are deployed from sea surface to seabed on different layers. Clustered-based routing mechanism with highest weighted value for data forwarding is based on seabed to bottom layer courier nodes through ordinary nodes. Bottom layer courier nodes collects the information from ordinary nodes and forwards to surface sink nodes by maximum power levels (p₁, p₂, …., p_n-1) through courier nodes which are deployed in different layers. For performance analysis the NS2.30 with AquaSim is used. The simulation results of CBE2R are compared with energy efficient REEP, EMGGR, and DRP. From simulation results it is observed that the performance CBE2R is higher than REEP, EMGGR and DRP.     

Improved emitter transit time using AlGaAs-GaInP composite emitterin GaInP/GaAs heterojunction bipolar transistors

A new emitter structure based on composite graded AlGaAs-GaInP approach is described, which allows significant reduction of CBE and improved high-frequency performance. A theoretical study of the composite and conventional emitter HBTs is performed to prove the superiority of composite emitter HBTs using Monte Carlo simulation of their transport properties. The self-aligned HBTs fabricated in this study are grown by CBE with TBA/TBP precursors. The current gain cutoff frequency (f_T) was 62 GHz for the composite emitter design HBT, and 45 GHz for conventional emitter design HBT. The CBE achieved with the composite emitter designs was at least 3 times lower than that of conventional designs and does not show significant variation with collector current. This leads to enhanced f_T characteristics by 15% for composite emitter HBT designs and confirms the theoretical expectations     

综述计算机辅助教育的若干问题

计算机辅助教育（CBE）是一种崭新的现代化教育手段,是以计算机为主要媒介所进行的活动。它既可用于优化教育与教学过程,又可用于改进教育与教学的管理,特别网络技术的发展,使这种新型的教学方式更加完善,因而已经改变或正在改变传统的教学模式。本文就它的几个基本问题进行了论述,以便让教师或学生对它有所了解。