氮化后退火——一种提高超薄热氮化SiO_2膜性能的有效方法

本文对超薄热氮化SiO_2膜(～100A)进行了研究,提出一种氮化后退火的新工艺,所得薄膜有很好的抗氧化特性,和SiO_2薄膜相比,其固定电荷及界面态密度相当,在高电场应力下膜中产生的正电荷及电子陷阱较少,较好的电击穿特性,抗辐射性能有很大的改善,因而,是一种性能优良的超薄介质膜.     

氮化后退火——一种提高超薄热氮化SiO_2 膜性能的有效方法

本文对超薄热氮化SiO_2膜(～100A)进行了研究,提出一种氮化后退火的新工艺,所得薄膜有很好的抗氧化特性,和SiO_2薄膜相比,其固定电荷及界面态密度相当,在高电场应力下膜中产生的正电荷及电子陷阱较少,较好的电击穿特性,抗辐射性能有很大的改善,因而,是一种性能优良的超薄介质膜.     

热氮化SiO_2膜性能的试验研究

本文报导对热氮化SiO_2膜的研究结果.热氮化SiO_2膜的腐蚀特性、抗氧化特性的研究表明膜的化学结构与SiO_2不同.采用AES表面分析技术观察了膜中化学成份,从而证实了膜中的氮含量取决于氮化前的SiO_2膜厚和氮化时的条件,热氮化SiO_2膜的电学特性、抗辐射性能明显优于SiO_2膜.     

快速热氮化SiO_2膜陷阱特性的研究

本文采用雪崩热电子注入技术研究了快速热氯化SiO_2膜和氮化后再氧化SiO_2膜的体电子陷阱和界面态特性。揭示出电子陷阱的起源和放电机理;观察并解释了界面态密度随氮化时间以及平带电压漂移随注入时间的变化关系;提出降低体电子陷阱密度和界面态密度的有效途径。     

热氮化二氧化硅对MOS特性的影响

人们发现,在高温下氨气中进行SiO_2的热氮化,可以形成有用的薄栅绝缘物,具有热氮化SiO_2膜的MOS二极管的界面特性明显地受氮化条件的影响。在900℃左右,由于氨气分介产生氢气使原来SiO_2膜的性质发生变化导致了平带电压有一个负的漂移,大于1100℃氮化时,得到一个极好的MOS二极管特性,避免了由原先介质击穿所产生的高电场不稳定性。在硅的间隙中央和绝缘物中的电荷可以忽略的情况下,获得了低于10~(10)cm~(-2)电子伏~(-1)的表面态密度。在SiO_2膜上形成一个防止沾污的高势垒。甚至于采用钠沾污栅,MOS二极管的可动离子密度     

MIS结构中快速热氮化的SiO_xN_y膜电荷特性

本文报导了采用光I—V法研究MIS结构中新型的快速热氮化的SiO_xN_y膜电荷特性。给出这种介质膜和传统的SiO_2膜的体电荷面密度及其分布重心位置等实验结果。文中还用“改进”的雪崩热电子注入装置研究MIS结构中快速热氮化的SiO_xN_y膜的电荷特性。结果指出:快速热氮化后的再氧化工艺可有效地降低SiO_xN_y膜的体电子陷阱和界面陷阱密度;雪崩注入到一定程度后平带电压漂移出现“回转效应”,随后又前漂,弱呈现“N”形。本文就此提出了物理解释。结果还给出:界面电荷陷阱密度在禁带中分布随雪崩注入剂量(时间)的变化关系。文中还对实验结果进行了分析讨论。     

热氮化SiO2绝缘栅H^＋—ISFET及其PH响应机理的探讨

本文介绍了采用NH_3退火热氮化SiO_2薄膜为绝缘栅兼做敏感膜制作H~+-ISFET,其在pH值为2～13的范围内具有较好的线性响应,灵敏度为41.6～47.8mV/pH,典型值为45.7mV/pH.并运用双表面基模型分析了H~+-ISFET的工作机理,较为合理地解释了以SiO_2、Si_3N_4或氮化SiO_2为介质膜的H~+-ISFET的响应特性.     

快速热氮化超薄SiO_2膜特性的研究

本文主要研究了超薄快速热氮化(Rapid Thermal Nitridation)SiO_2膜在高电场下的电特性和抗辐照特性,采用AES和XPS等技术分析了RTN SiO_2膜的成份和结构。与同厚SiO_2膜相比,RTN SiO_2膜具有许多明显的优点,在同样条件下,当电场强度E≈1.5×10~7V/cm时,击穿时间t_(bd)比SiO_2的约高两个量级;在经过剂量高达10~7rad的Co~(60)辐照后,SiO_2膜的界面态密度及漏电流均增大1—2个量级,而RTN SiO_2膜的变化非常小。     

PECVD形成纳米级薄膜界面陷阱的物理模型

采用雪崩热电子注入技术研究了纳米级富氮 Si Ox Ny 薄膜界面陷阱的物理模型。证实了 PECVDSi Ox Ny 薄膜中界面陷阱来源于悬挂键的物理模型。观察到该纳米膜内存在着受主型电子陷阱 ,随着注入的增长 ,界面上产生的这种陷阱将起主导作用。发现到 Dit随雪崩热电子注入剂量增加而增大 ,禁带上半部 Dit的增大较下半部显著。指出了雪崩注入过程中在 Si Ox Ny 界面上产生两种性质不同的电子陷阱 ,并给出它们能级位置及密度大小关系。揭示出 PECVD法形成的这种纳米膜与快速热氮化制备的薄膜中、氮氧含量不同、界面陷阱特性变化不一样 ,并从薄膜氮化机制予以物理解析。给出了 PECVD形成纳米级薄膜的优化工艺条件 ,该工艺条件制成膜的界面陷阱及其它物理电学特性都比较好     

PECVD形成纳米级薄膜界面陷阱特性的雪崩热电子注入研究

采用雪崩热电子注入技术研究了纳米级SiOxNy薄膜界面陷阱特性.证实了PECVD SiOxNy薄膜中界面陷阱来源于悬挂键的物理模型.观察到该纳米膜内存在着受主型电子陷阱,随着注入的增长,界面上产生的这种陷阱将起主导作用.发现到界面陷阱密度随雪崩热电子注入剂量增加而增大,禁带上半部增大得较下半部显著.指出了雪崩注入过程中在SiOxNy界面上产生两种性质不同的电子陷阱,并给出它们在禁带中的位置与密度大小关系.揭示出PECVD法形成的SiOxNy纳米膜与快速热氮化制备的这种薄膜中、氮氧含量不同、界面陷阱特性变化关系不一样,并从形成薄膜氮化机制上予以合理的物理解析.给出了PECVD形成纳米级薄膜的优化工艺条件.     

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.