溅射SiGe薄膜及其等时等温退火效应

分别在n-Si(100)和SiO2衬底上用离子束溅射法淀积SiGe薄膜.用俄歇电子谱测定薄膜Ge含量为15%～16%.对样品进行常规炉退火以考察退火温度和时间对薄膜结晶度的影响.采用X射线衍射确定薄膜物相.发现在同样退火条件下,SiGe在n-Si衬底上比SiO2上有更高的结晶度.通过曲线拟合,得到平均晶粒尺寸与退火温度和时间的依赖关系分别是自然指数和近线性的抛物线函数.推断出溅射SiGe薄膜的热退火结晶可能是晶粒生长控制过程.     

LPCVD-SiGe薄膜的物理及电学特性

采用低压化学气相沉积法(LPCVD),分别在n-Si和SiO2衬底上制备Si1-xGex薄膜。Ge的组分比由俄歇电子谱(AES)测定。对n-Si和SiO2衬底上的Si1-xGex分别进行热扩散和热退火处理,以考察热扩散和退火条件对薄膜物理及电学特性的影响。薄膜的物相由X射线衍射(XRD)确定。其薄层电阻、载流子迁移率及浓度分别由四探针法和霍尔效应法测定。基于XRD图谱,根据Scherer公式,估算出平均晶粒大小。数值拟合得到霍尔迁移率与平均晶粒尺寸为近似的线性关系,从而得出LPCVD-Si1-xGex薄膜的电输运特性基本符合Seto模型的结论。     

Ni诱导非晶SiGe薄膜结晶

采用Ni诱导结晶的方法在氧化硅衬底上制备多晶SiGe薄膜.通过X射线衍射(XRD)、俄歇电子深度分布谱(AES)等测试方法对获得的多晶SiGe薄膜特性进行了表征,并对退火气氛中氧的存在对非晶SiGe结晶的影响进行了研究.研究表明Ni的参与可以显著降低非晶SiGe薄膜的结晶时间以及结晶温度;退火气氛中氧的存在对非晶SiGe结晶有明显阻碍作用;采用先在高纯N2(99.99%)气氛下快速热退火(RTA)预处理,再在普通退火炉中长时间退火的方法可以明显改善非晶SiGe薄膜的结晶情况     

Ni诱导非晶SiGe薄膜结晶

采用Ni诱导结晶的方法在氧化硅衬底上制备多晶SiGe薄膜.通过X射线衍射(XRD)、俄歇电子深度分布谱(AES)等测试方法对获得的多晶SiGe薄膜特性进行了表征,并对退火气氛中氧的存在对非晶SiGe结晶的影响进行了研究.研究表明Ni的参与可以显著降低非晶SiGe薄膜的结晶时间以及结晶温度;退火气氛中氧的存在对非晶SiGe结晶有明显阻碍作用;采用先在高纯N2(99.99%)气氛下快速热退火(RTA)预处理,再在普通退火炉中长时间退火的方法可以明显改善非晶SiGe薄膜的结晶情况.     

SiO2衬底上PECVD-Si1-xGex薄膜研究

在覆盖SiO2的n-Si(100)衬底上,采用等离子体增强化学沉积法(PECVD)制备Si1-xGex薄膜材料。薄膜Ge含量x及元素的深度分布由俄歇电子谱(AES)测定。对Si1-xGex进行热退火处理,以考察退火温度和时间对薄膜特性的影响。薄膜的物相通过X射线衍射(XRD)确定。基于XRD图谱,利用Scherer公式计算平均晶粒大小。Si1-xGex薄膜载流子霍尔迁移率由霍尔效应法测定。数值拟合得到霍尔迁移率与平均晶粒尺寸为近线性关系,从而得出PECVD-Si1-xGex薄膜的电输运特性基本符合Seto模型的结论。     

不同柔性衬底上CdS薄膜退火前后的性能比较

采用磁控溅射法分别在柔性PI衬底、柔性AZO衬底和柔性ITO衬底上制备CdS薄膜,并在干燥空气中以CdCl2为源380℃退火,分别研究了不同柔性衬底及退火工艺对CdS薄膜形貌、结构和光学性能的影响。研究结果表明:退火前在不同柔性衬底上的CdS薄膜形貌依赖于衬底类型,退火后CdS薄膜的晶粒再结晶,晶粒度增大明显,且不再依赖于衬底类型。不同柔性衬底上CdS薄膜均为立方相和六角相的混相结构,退火后,六角相比例增大,薄膜的结晶质量提高。透过率退火后改善明显,其中,在柔性AZO衬底上的CdS薄膜透过率超过80%。     

溅射时间对氧化钒薄膜性能的影响

采用直流磁控溅射法在普通玻璃上制备了氧化钒薄膜,并对薄膜采取了450 ℃真空退火处理,分别测量了退火前后薄膜XRD图谱及电阻,比较了不同溅射时间（120 min、100 min、60 min）对薄膜性能的影响。结果表明,溅射时间增长,薄膜的结晶度也增强,经过退火处理,薄膜的电阻明显减小,且溅射时间越长,薄膜的阻值越小,3块薄膜的电阻分别达到16.0 MΩ、65.0 MΩ、71.5 MΩ,其随温度变化的幅度也越小。     

铜薄膜的直流磁控溅射制备与表征

根据薄膜的形成机理,用直流磁控溅射方法制备出了表面结构平滑、致密的Cu薄膜.实验中,采用纯度＞99.9%的铜靶,工作气压保持在2.7 Pa不变,玻璃衬底温度随环境温度变化.用X射线衍射仪(XRD)、扫描电镜(SEM)研究了薄膜的织构、晶粒尺寸和表面形貌.结果表明,随着溅射功率增大,薄膜织构减弱;溅射功率增大和溅射时间增加均可使薄膜的晶粒尺寸增大,在溅射功率≤100 W时获得的薄膜晶粒细小,有裂纹缺陷;溅射功率为150 W,溅射时间为30 min时,薄膜表面结构平滑、致密,晶粒尺寸相对较大.须进一步改进工艺参数,如衬底温度等,从而制备出表面结构平滑、致密、晶粒细小的薄膜.     

BST薄膜电容器的制备及其调谐性能研究

利用氩离子束溅射技术在SiO2/Si衬底上淀积Ba0.8Sr0.2TiO3(BST)薄膜,该薄膜在氧气气氛中500℃退火处理30 min,然后利用集成电路平面工艺将薄膜制作成叉指结构电容器。X-射线衍射仪(XRD)和扫描电镜(SEM)分析表明,BST薄膜具有钙钛矿结构,薄膜表面光滑,晶粒致密且分布均匀。调谐性能测试结果表明,该电容器具有较高的电容调谐率,在室温100 kHz频率下,对于2 V的直流偏压,其调谐率和损耗因子分别为62%和0.02。这说明具有此结构的BST薄膜电容器可望应用于微波集成电路。     

Si(111)上生长LiNbO_3薄膜的研究

利用射频磁控溅射的方法,在Si(111)衬底上制备了LiNbO3薄膜。采用X射线衍射(XRD)和扫描电子显微镜(SEM)研究了衬底温度、退火温度和溅射气体压强对LiNbO3薄膜结晶和表面形貌的影响,并用椭圆偏振仪测量了薄膜的厚度和折射率。结果表明:衬底温度为450℃时制备的薄膜,退火前后都没有LiNbO3相生成;衬底温度为500～600℃时,LiNbO3薄膜出现(012)、(104)和(116)面衍射峰,经600℃退火后3个衍射峰的强度加强;衬底温度为600℃时,经600～900℃退火得到的LiNbO3薄膜,除出现(012)、(104)和(116)面衍射峰外,还出现(006)面衍射峰;溅射气体压强从0.8 Pa增大到2.4 Pa时,经800℃退火后得到的LiNbO3薄膜表面晶粒团簇变小,而0.8 Pa制备的薄膜经800℃退火后LiNbO3相的结晶程度较其它压强下完善;900℃退火后得到的LiNbO3薄膜折射率为2.25,与LiNbO3晶体相当。     

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.     

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.