半绝缘砷化镓中EL2浓度的自动测量系统

本文介绍了使用通用计算机外部控制 PE Lambda-9分光光度计,设计完成了数据处理工作站,利用此工作站形成了一套半绝缘砷化镓中EL2浓度微区分布的自动测量系统。     

半绝缘砷化镓中EL2浓度的自动测量系统

本文介绍了使用通用计算机上部控制ＰＥＬａｍｂｄａ－９分光光度计,设计完成了数据处理工作站,利用此工作站形成了一套半绝缘砷化镓中ＥＬ２浓度微区分布的自动测量系统。     

半绝缘砷化镓的热激电流谱测量

本文介绍了热激电流谱(TSC)测试方法,测量了SI-GaAs材料的TSC特征谱图。并对SI-GaAs的深能级中心的行为进行了初步的分析。     

直径6英寸半绝缘砷化镓单晶生长技术通过专家鉴定

由中国科学院半导体研究所和北京中科镓英半导体有限公司共同承担的“863项目”——直径6英寸半绝缘砷化镓单晶生长技术研究成果，不久前通过了专家鉴定。鉴定委员会认为，该项目研制出的晶体技术指标均达到同期国内领先、国际先进水平，并且晶片加工技术指标也达到了国际先进水平。     

大直径LEC Si-GaAs中深施主缺陷的红外光谱分析

本文利用红外光谱分析技术系统分析大直径LEC (Light Energy Converter光能转换器)Si-GaAs中深施主缺陷EL2的浓度分布。实验结果表明,大直径LEC Si-GaAs深施主缺陷EL2浓度沿直径方向成w型分布,中心区域比较高,靠近中间区域最低,边缘区域最高。EL2是GaAs晶体中过量As存在的一种形式,其浓度强烈依赖过量As的浓度。晶体生长后的冷却过程中热应变场对过量As的分布会造成一定影响,同时位错密度的分布也会影响过量砷的分布,也就影响深施主缺陷EL2浓度的分布。     

大直径LEC Si—GaAs中深施主缺陷的红外光谱分析

本文利用红外光谱分析技术系统分析大直径LEC（Light Energy Converter光能转换器）Si—GaAs中深施主缺陷EL2的浓度分布。实验结果表明，大直径LECSi—GaAs深施主缺陷EL2浓度沿直径方向成W型分布，中心区域比较高，靠近中间区域最低，边缘区域最高。EL2是GaAs晶体中过量As存在的一种形式，其浓度强烈依赖过量As的浓度。晶体生长后的冷却过程中热应变场对过量As的分布会造成一定影响，同时位错密度的分布也会影响过量砷的分布，也就影响深施主缺陷EL2浓度的分布。     

六倍连续变倍双目立体显微物镜的光学设计

概要叙述了6x连续变倍双目立体显微镜光学系统的设计思想,包括光学系统参数的确定,显微物镜光学系统的结构形式的分析与选择,确定变倍部分的变倍与补偿方式及具体结构形式的考虑。     

显微镜-光学显微术用浸液

1范围本国际标准描述了用于显微术的浸液的特性,按其应用范围对浸液分类,并规定了每种型式的要求和试验方法。本国际标准规定了浸液的标记方法以及容器标签上的信息和技术数据单应提供的信息。     

显微红外光学成像系统的设计

红外热成像技术是现代影像学中的一门新兴技术。它与x射线、B超、CT、核磁共振等显像技术的成像原理不同,它不主动发射任何射线,只是被动接受热源所发射出的红外线,经过处理后得到热源的影像。该技术的最大特点是不用接触待测物体。因此,对于一些高危行业,如核工业中元器件的检测将变得非常容易。本文所叙述的就是利用红外热像技术与显微技术的结合,制作一种红外显微镜。红外显微镜可以将出现故障的大规模集成电路板中数以万计的微小元器件的影像传输到计算机中,经过计算机的分析,可以很容易地分析出具体故障所在。因此,大范同电子元器件故障的快速检测将变得简单、快捷。     

Investigation of dyed human hair fibres using apertureless near-field scanning optical microscopy

We present the first studies of dyed human hair fibres performed with an apertureless scanning near‐field optical microscope. Samples consisted of 5‐µm‐thick cross‐sections, the hair fibres being bleached and then dyed before being cut. Hair dyed with two molecular probes diffusing deep inside the fibre or mainly spreading at its periphery were investigated at a wavelength of 655 nm. An optical resolution of about 50 nm was achieved, well below the diffraction limit; the images exhibited different optical contrasts in the cuticle region, depending on the nature of the dye. Our results suggest that the dye that remains confined at the hair periphery is mainly located at its surface and in the endocuticle.     

Imaging an optical disc by the combined use of scanning tunnelling microscopy and scanning electron microscopy

We present the data obtained by scanning tunnelling microscopy combined with scanning electron microscopy of the digitally encoded structure on a stamper used to fabricate optical discs. The combination allows us to focus the STM tip on a preselected spot with a precision of ?0·3 μm. The data show the superiority of STM for a more detailed characterization of shape, width, length, height and fine structure appearing on the sample. We also show the influence of tip shape on STM resolution. Simultaneous use of both microscopes is possible but high electron doses produce an insulating layer of contaminants thick enough to make STM operation impossible.     

Scanning electron microscopy observation of the substructural evolution of aluminium alloys during cold rolling and partial annealing

Classical etching techniques for revealing cold deformation and partial recrystallisation in metals have been optimised for optical microscopy, which is limited by its resolution. Detailed studies of the mechanisms involved in recovery and recrystallisation during heat treatment are generally made by transmission electron microscopy. The limitation of this technique, with a few exceptions, is its small field of view and the small fraction of the sample available for inspection. The present article departs from the statement that etching, which is a surface alteration technique, must have effects that are detectable by scanning electron microscope (SEM). It was found that carefully adapted polishing and etching procedures allow for substructural investigations by SEM, resulting in various advantages compared with both optical microscopy and TEM.     

Imaging of thermal and elastic surface properties by scanning electron acoustic microscopy

Scanning electron acoustic microscopy is a new technique for imaging the thermal and elastic properties of surfaces and detecting subsurface flaws. It can be carried out in a modified scanning electron microscope. The effects of electron beam energy and phase angle on scanning electron acoustic images of the thermal and elastic properties of surfaces were studied with an alumina fiber/aluminum matrix composite for fiber directions both transverse and coaxial to the surface. Images produced with 10- and 30-keV electrons at beam modulation frequencies of 80–1200 kHz appeared to be identical, with the exception of a lower signal-to-noise ratio for the lower electron energy. This observation suggests that the energy input from the beam can be considered to occur at the surface for electron energies below 30 keV and frequencies below 1200 kHz. Images recorded at 0° phase angle mapped regions of different thermal and elastic properties. Images recorded at 90° phase angle highlighted the boundaries between such regions. Scanning electron acoustic microscopy can image features of different thermal and elastic properties at greater depth than traditional imaging with backscattered electrons. The practical application of the technique to the study of surfaces is illustrated by the imaging of grain structure and subsurface particles for an extruder barrel.     

Investigation of nanoparticles by atomic and lateral force microscopy

Metallic nanoparticles have been produced on vitreous carbon substrates by means of thermal evaporation. From pictures of the particles, made by a high-resolution scanning electron microscope (HRSEM), a semispherical shape is suggested due to the total mass of deposited material. Atomic force microscopy (AFM) has been applied to this sample in order to get direct topographic information. The AFM has been operated with normal and super tips, the latter having a smaller cone angle and radius, thus following more precisely the contours of an object. Simultaneously lateral-force microscopic (LFM) images have been recorded. Major differences between the contents of HRSEM- and AFM-images are considered, emphasizing the important influence of the tips' geometry. Both the AFM and LFM line scans have been compared with and have qualitatively agreed with those calculated under simplifying assumptions.     

Investigation of Bloch wall fine structures by magnetic force microscopy

Using a magnetic force microscope (MFM), measurements have been performed on single crystal iron whiskers. These samples exhibit a comparatively simple magnetic domain structure and a high degree of crystallographic perfection. STM measurements yield an average surface corrugation of about 3 nm. These nearly ideal boundary conditions permit an investigation of the undistorted surface configuration of Bloch walls in a cubic bulk crystal. Interactions between the stray field configuration of the sample and a ferromagnetic microscope tip have been measured with a new MFM device which is based on direct compliance detection. Measurements have been performed in the constant-current mode, as well as in the constant-compliance, mode. Control observation by means of the Kerr magneto-optic effect permit an interpretation of the obtained MFM data in terms of isolated 180° Bloch walls. The fine structure of these walls has been analysed and compared with results obtained from model calculations.     

Investigating the optical properties of dislocations by scanning transmission electron microscopy

The scanning transmission electron microscope (STEM) allows collection of a number of simultaneous signals, such as cathodoluminescence (CL), transmitted electron intensity and spectroscopic information from individual localized defects. This review traces the development of CL and atomic resolution imaging from their early inception through to the possibilities that exist today for achieving a true atomic-scale understanding of the optical properties of individual dislocations cores. This review is dedicated to Professor David Holt, a pioneer in this field.     

Single molecule mapping of the optical field distribution of probes for near-field microscopy

The most difficult task in near-field scanning optical microscopy (NSOM) is to make a high quality subwavelength aperture probe. Recently, we have developed high definition NSOM probes by focused ion beam (FIB) milling. These probes have a higher brightness, better polarization characteristics, better aperture definition and a flatter end face than conventional NSOM probes. We have determined the quality of these probes in four independent ways: by FIB imaging and by shear-force microscopy (both providing geometrical information), by far-field optical measurements (yielding throughput and polarization characteristics), and ultimately by single molecule imaging in the near-field. In this paper, we report on a new method using shear-force microscopy to study the size of the aperture and the end face of the probe (with a roughness smaller than 1.5 nm). More importantly, we demonstrate the use of single molecules to measure the full three-dimensional optical near-field distribution of the probe with molecular spatial resolution. The single molecule images exhibit various intensity patterns, varying from circular and elliptical to double arc and ring structures, which depend on the orientation of the molecules with respect to the probe. The optical resolution in the measurements is not determined by the size of the aperture, but by the high optical field gradients at the rims of the aperture. With a 70 nm aperture probe, we obtain fluorescence field patterns with 45 nm FWHM. Clearly, this unprecedented near-field optical resolution constitutes an order of magnitude improvement over far-field methods like confocal microscopy.     

Visualization of the native shape of bodipy‐labeled DNA in Escherichia coli by correlative microscopy

The native shape and intracellular distribution of newly synthesized DNA was visualized by correlative (light and electron) microscopy in ice embedded whole cells of Escherichia coli. For that purpose, the commercially available modified nucleoside triphosphate named BODIPY® FL‐14‐dUTP was enzymatically incorporated in vivo into the genome of E. coli mutant K12 strain, which cannot synthesize thymine. The successful incorporation of this thymidine analogue was confirmed first by fluorescence microscope, where the cells were stained in the typical for bodipy green color. Later the preselected labeled E. coli were observed by Hilbert Differential Transmission Electron Microscope (HDC TEM) and the distribution of elemental boron (contained in bodipy) was visualized at high‐resolution by an electron spectroscopic imaging (ESI) technique. The practical detection limit of boron was found to be around 5 ～ 10 mmol/kg in area of 0.1 μm², which demonstrated that ESI is a suitable approach to study the cytochemistry and location of labeled nucleic fragments within the cytoplasmic chromosomal area. In addition, the fine cellular fibrous and chromosomal ultrastructures were revealed in situ by combing of phase‐plate HDC TEM and ESI. The obtained results conclude that the correlation between fluorescent microscopy with phase‐plate HDC TEM and ESI is a powerful approach to explore the structural and conformation dynamics of DNA replication machinery in frozen cells close to the living state.     

Experimental confirmation of super-resolution in coherent confocal scanning microscopy using optical masks

Experimental results are presented which demonstrate super-resolution in a coherent scanning microscope. The microscope has a special optical mask, a Fourier lens and detector pin-hole to carry out optical processing of the image. The form of the special mask was calculated using the theory of singular systems.