4英寸高质量InSb晶体生长研究

InSb晶体是制备中波红外探测器的重要材料。为了满足新一代超大规模阵列红外焦平面探测器的发展需求,开展了大尺寸InSb晶体的生长研究,解决了晶体生长的诸多关键技术,成功地生长出了直径为4 in的高质量InSb单晶,并加工出了高质量的4 in InSb抛光晶片。测试表明,直径大于120 mm的晶体长度超过100 mm,晶体位错密度小于100 cm^-2,其电学参数均匀,载流子浓度、载流子迁移率均满足制备高性能大规格红外焦平面探测器的要求。这为新一代超大规模阵列红外焦平面探测器的发展奠定了良好的材料基础。     

InSb焦平面探测器的J-T制冷器

论述了InSb红外探测器制冷的必要性及所需的制冷温度，分析了InSb焦平面探测器对制冷的要求比分立引出（或单元）探测器更为严格的原因，指出InSb焦平面探测器的制冷温度在77－90K区间，其探测率变化不大；在137K时，分立引出（或单元）InSb探测器仍有较高输出信噪比，但这时焦平面探测器的SNR却有较严重的下降。试验表明，采用J－T节流制冷器的InSb焦平面探测器可以实现高性能。     

InSb薄膜分子束外延技术研究

InSb材料由于其优异的光电性能,一直是军事领域重要的红外探测器材料。而高温工作是InSb发展的一个重要方向,开发分子束外延InSb材料是实现高温工作的基础。本文采用分子束外延工艺生长获得了高质量的InSb薄膜,通过金相显微镜、X射线双晶衍射仪、原子力显微镜、SEM和EDX等检测手段对InSb外延膜进行表面缺陷、晶体质量表征和分析,并采用标准的InSb器件工艺制备128×128焦平面探测器芯片进行材料的验证,结果表明该材料性能可以满足制备高性能器件的要求。     

锑化铟红外焦平面探测器发展现状

近年来,红外探测器技术发展迅速,在国防、气象、红外遥感和航空航天等众多领域应用广泛。作为中波红外波段最重要的探测器之一,锑化铟(InSb)红外焦平面探测器具有量子效率极高、暗电流小、器件响应线性度高、稳定性好、灵敏度极高等特点,因此备受人们的关注和重视。InSb焦平面探测器性价比高,优势十分突出,其快速发展在很大程度上提高了红外整机性能,同时还覆盖了导弹精确制导、卫星预警探测、机载搜索侦察、红外成像及消防、医疗、电力检测、工业测温等军民两用领域。梳理了国外发达国家在InSb红外焦平面探测器方面的研究情况,分析了其发展方向并对发展前景及趋势进行了展望。     

100 mm直径低位错密度InSb单晶生长研究

InSb是一种重要的中波红外探测器材料。为了满足更大规模、更高质量红外焦平面探测器的发展要求,对100 mm直径低位错密度InSb单晶的生长进行了研究。通过改良生长方法、优化籽晶、改进缩颈工艺、优化热场,最终获得位错密度小于等于100 cm-2、直径大于等于100 mm的大尺寸低位错密度InSb晶体。晶体沿晶棒从头到尾部的位错密度分布均匀,可用率高,能够满足大规模高质量红外焦平面探测器的使用需求。     

4 in InSb晶片加工技术研究

在红外探测领域,InSb材料已经大规模地被用于制造3～5 μm波长范围的焦平面阵列探测器。对更大规模、更高性能探测器的需求日益增长,而该类探测器需要在更大尺寸、更高质量的晶片上制备。所以,对4 in InSb晶片加工技术进行了研究。通过优化研磨、抛光工艺参数,最终获得总厚度偏差小于等于10 μm、翘曲度小于等于20 μm、表面粗糙度小于1 nm、表面质量优的4 in InSb晶片,提高了加工效率,能够满足大规模高质量红外焦平面探测器的使用需求。     

电感耦合等离子体刻蚀InSb芯片工艺的研究

随着InSb红外焦平面阵列探测器的发展,焦平面阵列规模不断增大,像元面积越来越小.湿法刻蚀因为其各向同性刻蚀的特点,导致像元的钻蚀严重,已经难以满足大规格InSb焦平面器件的要求.采用电感耦合等离子体(ICP)刻蚀大规格InSb阵列芯片,研究不同腔体压力对刻蚀速率、表面形貌的影响及InSb表面残留聚合物的去除方法.     

锑化铟焦平面阵列的性能预测

由于锑化铟材料的工艺成熟、生产率令人满意及其优良性能,使它能在中波长(2-5.4μm)的红外系统中被优先选用。只是在超过130K温度下,InSb才不如其他探测器材料。为了实现在大阵列制式中InSb探测器固有的高性能,必须设计出一种低噪声、使InSb与焦平面电子学隔离及适合特殊应用的速率要求的读出装置。为了获得最高性能,读出装置必须有一个以上的简易开关矩阵。讨论了转换积分器和缓冲共栅极输入电路,并将它与一创新的斩波器-稳定器电路作比较。稳定电路是使用了载流子调制技术,将探测器信号向上转换成较高的频率,其中MO-SFFT的1/f噪声很低。对质量不同的InSb探测器与为提高工作温度(>100K)的探测器阻抗匹配而专门设计的斩波器-稳定读出装置相接的焦平面性能作了预测。     

Si基InSb红外焦平面阵列探测器的研究

针对InSb 红外焦平面芯片中InSb 与Si 读出电路热膨胀系数不匹配导致芯片龟裂及铟柱断裂现象,开展了Si基InSb 红外焦平面探测器（FPA）的研究。运用磨抛减薄技术及金刚石点切削技术对芯片背面进行精确减薄,得到厚度为15m的InSb芯片;研究了在InSb芯片和Si片上溅射及蒸发减反膜工艺,得到InSb芯片和Si片粘贴后红外中短波光谱的透过率高达88%;对器件的整体工艺路线进行了探索,最终制备出Si基128128元InSb 红外焦平面探测器器件,测试结果表明:器件探测率、响应率及串音等性能指标达到传统工艺制备的器件性能指标;经温冲试验后测试器件结构保持完好,性能未发生变化,证明该工艺路线可解决芯片受应力冲击而产生的铟柱断裂及芯片龟裂的现象,可有效提高InSb焦平面探测器芯片的成品率。     

应力制约的InSb焦平面探测器均匀性

采用焦平面探测器均匀性作为衡量InSb芯片承受应力的方法,通过工艺改进有效地降低了应力水平,提高了128×128 InSb焦平面探测器的均匀性,取得了响应非均匀性为3.0%的结果.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.     

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.