透射电镜与扫描电镜分析

文章简要介绍了透射电镜和扫描电镜两种当前主要的电子显微分析方法的应用,比较了它们的结构和工作原理,讨论了各自的应用范围以及发展方向,指出将两者有机结合可以得到比较全面的材料分析结果。     

The scanning electron microscope

The scanning electron microscope combines the techniques of the cathode-ray tube and the conventional electron microscope?both considered indispensable to modern technology. The SEM, which presents a picture having a distinct three-dimensional appearance, is finding application in the examination of wood fibers in connection with paper manufacture, of surfaces undergoing ionic bombardment, and of corrosion. At the present time, one of the most pressing problems is to reduce its total cost.     

全计算机控制扫描电镜

随着计算机技术的飞速发展,各行各业都离不开计算机技术。在扫描电镜行业,全计算机控制的扫描电镜,使扫描电镜的操作自动化、多功能化、简单化提高到了新的水平。近几年来,国外电镜厂家纷纷研制出全计算机控制扫描电镜。我们结合多年从事分析仪器的开发、制造和应用研究经验,开发成功国内第一台全计算机控制扫描电镜KYKY-3800,它使用先进的计算机技术,实现了传统扫描电镜由面板控制到全计算机控制的升级。整个电镜的操作系统使用全新的WINDOWS操作界面,用户只须按动鼠标,就可实现电镜镜筒和电气部分的所有控制,同时,可实现一些工作状态…     

大豆豆荚的扫描电镜观察

大豆在结荚鼓粒期叶片的光合速率与籽粒产量呈显著正相关性。而大豆豆荚光合作用及其与籽粒生长发育关系的研究则极少见报。因此在幼荚期、鼓粒期和成熟期,研究大豆荚果的形态发生、发育机理及豆荚对籽粒生长的供需关系,对提高大豆产量及高光效大豆品种的选育具有十分重要的意义。     

Nonlinearity estimation of scanning on a scanning electron microscope

The nonlinearity of scanning on a scanning electron microscope (SEM) of nanorelief elements with known geometric profile shapes is estimated. The average pitch value of the relief test structure is measured, when the studied sample is shifted along the X-axis (scanning axis). As an index that characterizes the nonlinearity of the SEM scanning with the stated sample displacements, the relative mean-square deviation from the average pitch value of the test structure is selected. It is experimentally shown that, when the magnification is 20k, this value is 0.4%, which is in the tolerance error range.     

大豆种柄的扫描电镜观察

大豆种柄是籽粒与子房内壁的连接点,是植株向籽粒传送同化物质的唯一通道。因此种柄在大豆发育过程中,对光合器官的光合作用产物向籽粒中运输起着十分重要的作用。     

Noncontact high-speed waveform measurements with the picosecondphotoelectron scanning electron microscope

The authors have replaced the electron gun and beam blanking system of a conventional voltage contrast scanning electron microscope by a pulse-laser/photocathode combination, resulting in a source producing electron pulses of order 1 ps in duration at a 100 MHz repetition rate and with a peak brightness of 3 10⁸ A/cm² sr at 1.8 keV. This novel instrument has demonstrated stroboscopic noncontact waveform measurements on metal interconnect lines in different environments with a temporal resolution between than 5 ps, a voltage resolution of 3 mV/(Hz)^1/2, and a spatial resolution of 0.1 μm. These measurements are achieved with extraction fields above the sample of about 1 kV/mm     

不同粒型小麦品种胚乳淀粉体的扫描电镜观察

对3个不同粒型小麦品种胚乳淀粉体的大小,形状、分布和发育等特性进行了扫描电镜观察。结果表明,3个品种胚乳细胞淀粉体均为单粒淀粉,可根据淀粉体的大小分为三种类型：Ⅰ、Ⅱ,Ⅲ,型。Ⅰ型为椭球形,大粒淀粉;Ⅱ型为椭球形或橄榄球型,中粒淀粉;Ⅲ型为近圆球形,小粒粉,鄂恩1号Ⅱ型淀粉体多为橄榄球型,明显异于其它品种。各品种颖果腹部Ⅰ、Ⅱ型淀粉体多,排列紧密,背部Ⅲ型淀粉体较多,中间胚乳细胞淀粉体以Ⅰ、Ⅲ型为主,排列疏松。颖果腹部淀粉的发育和排列明显优于背部和中间,小粒型品种胚乳细胞淀粉体育好,淀粉充实度高;大粒型品种相反,淀粉体排列疏松,发育差,大粒淀粉体通过网状膜与中小淀粉体相连。     

扫描电镜中的算法进展

在过去的二十年中,同透射电镜一样,在扫描电镜上也取得了许多硬件的进展,如浸没式物镜、减速模式和新型探测器技术.测试技术的进步包括硬件和软件两方面内涵.伴随硬件的进步,借助信息科学(包括人工智能(AI)和其他统计数学方法),人们在成像和光谱学方面也有了新的机遇.硬件与软件结合,可以实现更高精度、更高通量的表征,也使得如今...     

扫描电镜图片的彩色处理初步体会

众所周知 ,由于扫描电镜的照明光源是准单一波长的电滋波 ,故观察到的图像只能是黑白图像。再精美、漂亮的电镜图片 ,也不例外由黑白灰度构成 ,如果把它彩色化会更有利于区分不同结构 ,突出重点 ,达到通俗易解 ,并具备优美的艺术性。目前其它自然科学图片的彩色化已与国际水平接近 ,但ＳＥＭ彩色化国外近年才有所开展 ,而国内尚少见。随着计算机技术的发展 ,电子显微镜也逐步受控于计算机 ,且由于图像处理软件的功能日益强大 ,我们经过反复摸索 ,将一幅幅色彩丰富的扫描电镜图片 ,展现在电镜同仁们的面前。Ｐｈｏｔｏｓｈｏｐ系列软件是美国…     

Computer-controlled resist exposure in the scanning electron microscope

In modern microelectronics, complicated structures with very small dimensions must be fabricated on active-device materials. This task has been traditionally accomplished by photolithographic techniques, but electron-beam exposure of resist materials has recently been explored [1]-[3]. Submicron electron devices have been fabricated in several laboratories, often featuring a flying-spot scanner to generate the pattern being exposed [4]-[7]. Paper tape drives have been used for repetitive patterns [8], and computer control of the electron beam has been reported also [1], [9]. The electron resist that has shown the highest resolution to date appears to be poly-(methyl methacrylate) (PMM). We have used this material in a resist form for microelectronic device fabrication, and in bulk form to determine energy dissipation profiles. The exposure is performed with a computer-controlled scanning electron microscope (CCSEM). In this paper, we describe the electron beam system briefly, discuss the processes involved in resist exposure and development, describe our exposure procedures using the CCSEM, and show results of fabricated devices and energy dissipation studies.     

Applications of the scanning electron microscope to solid-state devices

Applications of the techniques of scanning electron microscopy to solid-state devices are reviewed from the device point of view. An explanation is given of the Scanning Electron Microscope and of the phenomena in this instrument currently judged to be of greatest pertinence to devices. The simultaneous observation of physical topography and voltage contrast is explained, and Scanning electron micrographs of actual device structures are presented. Application of this instrument to the polymerization of photoresist films is also discussed, and it is shown that a factor of five to ten improvement in the control of edge sharpness is obtained over images produced by conventional optical techniques. The implications of these techniques to the fabrication of microdevices are discussed in the terms of a relatively simple field-effect device structure.     

Microcharacterization of electroluminescent diodes with the scanning electron microscope (SEM)

A complete material characterization of electroluminescent diodes necessarily requires a high spatial resolution because of the micron-sized thickness of the different epitaxial layers. A modified arrangement of a scanning electron microscope (SEM) has proven to be an extremely useful tool for obtaining information on the various parameters of each of these layers. It will be shown that the analysis of the electron beam induced voltages (EBIV) and currents (EBIC) allows not only the location of the junction itself, but also the detection of all other built-in barriers. Measurements of the EBIC permit separation of barriers less than 1 µm apart; even barriers in a direction oposite to that of the junction are detected in this manner. The peak value of EBIC is largely independent of the barrier height, but it is sensitive to variations in the concentration of the components of the lattice. Because of the exponential decrease of EBIC with the distance between primary electron beam and barrier, the minority carrier diffusion length can be obtained for all different barriers. The height of barriers, 2.5 µm separated and with the same direction as the p-n junction, can be determined quantitatively by the maximum of EBIV. By measurement of the cathodoluminescence (CL) signal regions of different recombination probabilities for radiative transitions (and therefore different luminescence yields) can be distinguished. Thus inhomogeneities of the structure can be detected. By spectral CL analysis the spatial variation of the width of the bandgap will be shown.     

Theory of lifetime measurements with the scanning electron microscope: Transient analysis

A transient analysis of an SEM experiment is given with the purpose of determining directly the lifetime of minority carriers in a semiconductor material. The injection takes place below a surface normal to the junction and expressions are derived for the current-decay which ensues when the electron beam is cut off. The decay of the current is shown to be overall different from a purely exponential one. Indeed, the results, which are given for zero and infinite surface-recombination velocity, v_s, show a time-lag in the current-decay, which increases with the distance of the beam from the junction. Even in its final stages the decay fails to be purely exponential. It is shown that serious errors in the evaluation of lifetime may occur if the true nature of the decay is not taken into account.     

扫描电子显微镜在煤岩学上的应用

煤作为一种固体可燃有机岩，是我国长期依靠的重要能源。作者总结多年扫描电子显微测试分析工作，将扫描电镜在煤岩学上的应用大致归为以下几个方面。     

大豆根瘤的扫描电镜观察

大豆与大豆根瘤处于一个共生的体系,大豆为大豆根瘤的生长提供适宜的微观环境,而大豆根瘤则为大豆植株的发育提供必要的养分.豆科植物的生物固氮能力是通过根瘤菌的侵染完成的.大豆根被根瘤菌侵染后,形成共生体根瘤,根瘤菌通过生物固氮作用将空气中的氮转化为氨供给大豆利用.本实验以东农46为研究对象,利用扫描电子显微镜技术,对大豆发育过程中根瘤、根瘤菌和淀粉粒的结构特征、形态变化进行超微结构观察.结果表明,大豆发育过程中根瘤的发育可分为三个时期,即:根瘤菌的侵入和感染;根瘤的形成和发育;根瘤及根瘤菌退化.各时期的根瘤菌经历了形态及数量发育的变化,由初期数量较少、形态不规则,到数量大幅度增加充满侵染细胞,最终随着侵染细胞开始衰亡其内部的根瘤菌逐渐减少至全部消失.     

扫描电子显微镜在植物中的应用研究进展

扫描电子显微镜(SEM)作为一种行之有效的科研分析工具,可对多种植物材料的表面形貌进行观察研究,具有较广的应用范围.本文论述了扫描电子显微镜样品的制备以及在植物花器官、种子表皮、种子形态、叶片表皮、内含物、病原体以及在植物细胞水平的研究进展,并对今后扫描电子显微镜的应用前景进行了展望,以期为利用SEM从事植物研究的科研...     

扫描电镜在砂岩孔隙铸钵上的应用

砂岩孔隙铸体是将地下含油水的岩石经洗油烘干，放到铸体仪中将树脂通过真空灌注，高温、高压固化，再酸化去除岩石颗粒，只保留孔隙骨架，表面再利用镀模机处理，利用扫描电镜进行观察和鉴定，获得砂岩孔隙特征的微观形貌信息。     

一种扫描电镜下纳米操纵台的设计

本研究组设计了一种在场发射扫描电镜下进行纳米操控的装置——纳米操纵台(图1)。利用该纳米操纵台可实现原位下对纳米点、线和膜材料空间三维上的操作与观察。     

Time of flight spectrometer for scanning electron microscope

Experimental results which show the feasibility of use a time-of-flight spectrometer to obtain energy information of emitted electrons in a scanning electron microscope (SEM) are presented. The method is able to simultaneously display the energy distribution of emitted electrons over their entire energy range, from elastic backscattered electrons down to the low energy secondary electrons, and is thus predicted to have major signal-to-noise benefits for topographic, material, and voltage contrast in an SEM.<>