GapLPE半导体材料的扫描电子显微镜研究

本文论术了用扫描电子显微镜ＧａＰＬＰＥ半导体材料，二次电子像用于分析样品的表面形貌     

防潮的方法和成分

本专利涉及表面涂油防潮、防雾的方法。更详细地说是涉及用新的硅碳氟化合物涂在硅质表面上防潮、防雾。特别是提到新的硅碳氟化合物涂在羟基表面上,防潮的时间长。大家知道,用各种化学剂和混合剂去处理硅质表面,像:汽车和飞机的档风玻璃、民房和商业楼房的窗玻璃对于防潮、防雾多少还是有效的。然而,这样处理的不足之处是:所要求的延续时间比较短,因为受机械磨损、元件自然磨损以及像光透射的干扰等的限制。已经发现,羟基表面用下列式中的小量混合物基本可以防潮。     

衍射光学元件杂散光分析的数据结构及鬼像分析

当光学系统中存在衍射元件时,特别是高功率激光光学系统中,由于多级衍射和多次反射的存在,因此系统中将会产生危害性的杂散光和鬼像。提出了一种用于衍射光学元件杂散光分析的树形数据结构,树的每一个结点描述了系统中两个表面之间传输的光束参数,并且根据光路计算结果,动态地开辟内存空间存放杂散光和鬼像的位置、能量等数据。对含1个衍射面和7个常规面的光学系统作了实例计算,表明用这种数据结构可以全面分析系统中的杂散光,给出鬼像位置和估计鬼像能量。当取最高反射次数为4次,衍射级为0到±5级时,运行时间在1s以内,成功地分析了该红外光学系统的鬼像。     

红外热像仪测量切削温度的误差来源分析与实验研究

用红外热像仪测量切削温度时,拍摄角度、距离以及物体表面发射率都是导致测温误差的来源。在红外热像仪测温理论分析的基础上,对这些因素用控制变量法进行实验。结果结果表明,拍摄角度在5o~10o和30o~35o这两个范围内,测温误差较小。热像仪与切削区之间的距离在1.1m~1.2m的范围内,测量温度比较稳定。对于粗加工45号钢而言,表面发射率设在0.48~0.45之间,温度波动较小,此区间的发射率为较好。研究结果对于红外热像仪现场监测切削温度,具有实际的指导意义。     

基于96A热像仪图像可视化识别

使用偏微分方程(PDE)方法,对96A热像仪断层扫描(CT)数据进行可视化研究,同时采用两种基本的图像可视化方法,实现了表面重建和立体绘制,其基本原理是通过PDE方法将相关元素集成到单一的面板当中,即首先使用偏微分方法用CT进行表面扫描,其输出相关参数后用PDE方法确定边界条件,而后在提取边界条件下,进行底部表面重建。PDE方法被广泛地用于立方体构建,并能够有效地识别表面特征。通过将Alpha第三个参数w引入PDE方法中,可以创建出一个实心的几何体,在此基础上,用3D纹理贴图绘制几何体的体积。适度调节相关传递函数,并将三维纹理的Alpha值与PDE参数w相关联。实验结果表明了该方法可以获得较清晰的热像图像。     

X射线衍射和散射光束线环面聚焦镜的面形精度与像差分析

介绍了用于NSRL的X射线衍射和散射光束线中环面聚焦镜的成像原理和基本结构,分析计算了各种像差和面形精度对成像质量的影响,重点描述了镜子因受力弯曲在子午方向的曲率变化与理论值的误差以及反射表面受同步辐射光照射而产生的热载变形,进而求得实验样品上束斑成像的高度.最后用CCD探测实际光斑的尺寸,结果表明:理论计算与实测数据非常吻合.     

机械密封摩擦环粗糙表面的计算机模拟

用计算机模拟仿真机械密封摩擦环的粗糙表面,该方法能得到与工程实际较为吻合的密封环表面的三雏形貌,以及表面轮廓高度的分布数值,可用于为机械密封环表面润滑、摩擦等性能的数值分析提供数据输入.     

重型铝合金结构裂纹振动红外热像检测的建模和分析

为了实现重型铝合金承力结构裂纹的振动红外热像无损检测,优化检测条件,提出振动热像检测的数学模型,用解析法研究金属裂纹振动热像检测的检测条件和影响因素。用试验说明振动热像法的有效性,用强迫振动理论和瞬态传热理论对振动热像法进行数学建模和解析计算,得出裂纹区表面温升与裂纹阻尼、激振力幅值、激振频率、激振时间、裂纹深度等力学参数的函数关系。结果表明,理论计算结果与试验现象相吻合,所提出的解析模型可以精确地描述多种主要力学参数对振动热像的影响规律。以建模和解析法研究振动热像法的振动发热规律对揭示其内在规律和建立标准操作参数窗口具有普遍意义     

基于ObjectARX 2004的表面粗糙度自动标注

介绍了在AutoCAD环境下基于ObjectARX 2004和微软基础类库(Microsoft Foundation Class,MFC)用户界面的表面粗糙度自动标注技术,它可像AutoCAD内部命令一样很方便地被使用,也可用于参数化设计.对Visual C++.NET开发环境的设置、自动标注的编程要求及编程中的若干问题进行了讨论和解决,最后给出了表面粗糙度自动标注的实例.     

国产3D面积测定仪在食品接触用制品表面积测定中的应用

采用汇像PHS620BF型3D面积测定仪,分别对正方体、圆柱体、半球体标准块的表面积,以及7种不同材质和颜色食品接触用制品的选定表面区域的面积进行测定。测试结果表明,3种标准块表面积测定结果的RSD值为0.142%～0.177%,RE值为-2.89%～-1.09%;7种食品接触用制品的面积测定结果RSD值为0.0758%～1.27%。可以得出:该3D面积测定仪对3种标准块和7种食品接触用制品的表面积测定数据较为良好,可以用于食品接触用制品的检测工作。     

High-resolution scanning near-field EBIC microscopy: application to the characterisation of a shallow ion implanted p+-n silicon junction

High-resolution electron beam induced current (EBIC) analyses were carried out on a shallow ion implanted p⁺–n silicon junction in a scanning electron microscope (SEM) and a scanning probe microscope (SPM) hybrid system. With this scanning near-field EBIC microscope, a sample can be conventionally imaged by SEM, its local topography investigated by SPM and high-resolution EBIC image simultaneously obtained. It is shown that the EBIC imaging capabilities of this combined instrument allows the study of p–n junctions with a resolution of about 20 nm.     

Advanced semiconductor diagnosis by multidimensional electron-beam-induced current technique

We present advanced semiconductor diagnosis by using electron-beam-induced current (EBIC) technique. By varying the parameters such as temperature, accelerating voltage (V(acc)), bias voltage, and stressing time, it is possible to extend EBIC application from conventional defect characterization to advanced device diagnosis. As an electron beam can excite a certain volume even beneath the surface passive layer, EBIC can be effectively employed to diagnose complicated devices with hybrid structure. Three topics were selected to demonstrate EBIC applications. First, the recombination activities of grain boundaries and their interaction with Fe impurity in photovoltaic multicrystalline Si (mc-Si) are clarified by temperature-dependent EBIC. Second, the detection of dislocations between strained-Si and SiGe virtual substrate are shown to overcome the limitation of depletion region. Third, the observation of leakage sites in high-k gate dielectric is demonstrated for the characterization of advanced hybrid device structures.     

The effect of electron range on electron beam induced current collection and a simple method to extract an electron range for any generation function

The effect of electron range on electron beam induced current (EBIC) is demonstrated and the problem of the choice of the optimal electron ranges to use with simple uniform and point generation function models is resolved by proposing a method to extract an electron range-energy relationship (ERER). The results show that the use of these extracted electron ranges remove the previous disagreement between the EBIC curves computed with simple forms of generation model and those based on a more realistic generation model. The impact of these extracted electron ranges on the extraction of diffusion length, surface recombination velocity and EBIC contrast of defects is discussed. It is also demonstrated that, for the case of uniform generation, the computed EBIC current is independent of the assumed shape of the generation volume.     

Monte Carlo simulation of CL and EBIC contrasts for isolated dislocations

Electron beam-induced current (EBIC) and cathodoluminescence (CL) are widely used to investigate semiconductor materials and devices, particularly to obtain information on the recombination properties and the geometry of defects. This report describes a simple formulation of CL and EBIC contrasts based on the Born approximation of excess carrier density in the presence of a pointlike defect. Quantitative interpretation of the CL and EBIC images is often difficult because of a lack of accurate theory treating simultaneously both the details of the electron beam penetration in the semiconductor and the generation of EBIC and CL signals. To overcome this difficulty, the Monte Carlo approach to the phenomenon of the electron beam penetration in solids has been developed to calculate the CL and EBIC signals during a simulation of the electron trajectory. Results for an inclined dislocation in GaAs are presented.     

Observation of dislocations and microplasma sites in semiconductors by direct correlations of STEBIC,STEM and ELS

A high voltage electron microscope, equipped with scanning transmission (STEM) attachment, electron beam induced conductivity (EBIC) facilities, and electron energy loss spectrometer (ELS), has been used to investigate semiconductor devices. The capability of STEM to produce, simultaneously or sequentially, conductive and transmission images of the same specimen region, which can also be ELS analysed, is exploited in order to establish direct and unambiguous correlations between EBIC and STEM images of defective regions (dislocations and microplasma sites) in silicon devices. The results obtained are discussed in terms of correlations, resolution, contrast, and radiation damage; in addition, a comparison is made between this method and the other correlation methods based on EBIC/SEM (scanning electron microscope) and TEM (transmission electron microscope).     

A computerized signal acquisition system for the quantitative evaluation of EBIC and CL data in a SEM

Electron beam-induced current (EBIC) and cathodoluminescence (CL) are widely used methods to obtain information about recombination properties of semiconducting materials and their defects on a micrometer length scale. In this article a computerized SEM (scanning electron microscope) setup is described, which enables us to perform simultaneous measurements of several signals and automatic temperature-dependent measurements. As examples for the performance of this system we present results obtained by simultaneous EBIC/CL experiments, allowing a reconstruction of the defect geometry. In a second example, the temperature dependence of the EBIC contrast is analyzed, introducing the method of EBIC spectroscopy.     

The interpretation of EBIC images using Monte Carlo simulations

Charge collection microscopy, usually known by the acronym EBIC (Electron Beam Induced Current) imaging, is a powerful technique for the observation and characterization of semiconductor materials and devices in the scanning electron microscope. Quantitative interpretation of EBIC images is often difficult because of the problem of accurately representing the electron-beam interaction with the semiconductor. This paper uses a Monte Carlo technique to simulate the electron-beam interaction, and it is shown that this permits simple analytical point-source solutions to be generalized to fully represent the experimental situation of an extended, non-uniform, carrier source. The model is demonstrated by application to EBIC imaging in the Schottky barrier geometry.     

Scanning electron microscopy studies of double-layer silicon structures prepar by epitaxy and direct bonding

The electrical properties of multilayer structures obtained by direct bonding of silicon wafers and epitaxial growth have been investigated. The measurements were made by scanning electron microscopy (SEM) in either secondary electron or electron beam-induced current (EBIC) regime, using cross sections of the structures with a p-n junction formed in the subsurface region of the active layer. The measurements of defect recombination activity were made using Schottky diodes formed on the active layer surfaces. Parasitic p-n junctions in some samples under a small direct voltage have been observed and the reason for the appearance of such parasitic junctions has been established. Two types of defects with different distribution densities and amplitudes of EBIC contrast have been detected.     

Direct assessment of recombination noise in semiconductors using electron beam-induced conductivity

The level of internal noise of the transistors, diodes, and other semiconductor components limits the successful design of any low noise electronic system. All types of noise, namely, Johnson, 1/f, and so forth, are generated due to activity of crystalline defects such as vacancies, dislocations, and others. The intensity of the electron scattering and recombination processes, inflicted by defects (traps), controls the level of noise. Dependent on the dynamic operation condition of semiconductor devices, such as external biases and level of current injection, the traps will generate certain type and level of noise. Material growth or device processing technologies could introduce all kind of defects. Therefore, characterization of the semiconductor wafer in the early stages of processing (at least before packaging) could help to predict the level of noise due to the type and density of defects present on the wafer. Sorting out bad semiconductor chips could save money and effort in the radio frequency design of low-noise circuits. This current study focuses on 1/f noise modeling, which involves most powerful generators of noise and linear defects, named dislocations. The study also examines the possibility of assessing this noise by quantitative electron beam-induced conductivity (EBIC) measurements. These defects could be found in the bulk as well as at the epitaxial interfaces of a semiconductor device. The nanoscale size of these defects makes the scanning electron beam an instrument of choice for the proposed study. Conventional EBIC produces images of the defects, where contrast is proportional to the recombination rate at the site of a defect. Since contrast is measured as a fraction of one percent, the relative nature of contract value precludes quantitative measurements of the recombination rate, thus making quantitative assessment of 1/f noise impossible. In our model, using the Boltzman continuity equation, the recombination-generation processes per unit of length of a dislocation was defined for two operational conditions of EBIC, namely, for low and high intensity of an electron beam. The experimental technique of the quantitative measurement of carrier recombination (Mil'shtein 2001) consists of taking two EBIC scans along the selected defect at two different beam intensities, digitally subtracting the first scan from the second one and normalizing the result to the size of the electron range. The value of the recombination rate, extracted from the model, could then be used to predict the level of 1/f noise in the tested semiconductor sample.     

Observation of current-density filamentation in multilayer structures by EBIC measurements

The total current-voltage characteristics of the p⁺-n⁺-p-n^? and n⁺-p-n-p^? diodes under investigation show branches of negative differential resistance. Accompanied by the appearance of negative differential resistance is a filamentation of current-density and electric-field distribution. Electron beam-induced current (EBIC) measurements were used to examine the properties of filamentation from the point of view of self-organized pattern formation. Besides the detection of the spatial distribution of the electric field, EBIC measurements give information on current-density filamentation. Furthermore, the perturbation by the electron beam gives information on the dynamic behavior of the filamentary structure.