Comparison of dislocation images obtained using the scanning optical microscope and scanning electron microscope

Dislocations in a silicon specimen containing a p-n junction have been imaged with a scanning optical microscope (SOM) and a scanning electron microscope (SEM) using the induced carrier mode. Examination of the same dislocations by the two methods has shown that virtually identical images are obtained and the spatial resolution is 1m.     

Liquid-helium stage in a scanning electron microscope

A liquid-helium stage to be inserted into a scanning electron microscope (SEM) is described. The sample chamber, which is filled with liquid helium, has a volume of about 8 × 7 × 5 cm³. Translation of the cooled sample in x, y, and z directions is possible during electron-optical observation. Since mounting the liquid-helium stage to the SEM can be performed in less than 30 min, switching the SEM from regular operation at room temperature to the low-temperature mode and back is relatively easy. After cooling the system to 4.2 K, a 3 litre helium reservoir allows experimentation near 4.2 K for about 5 h.     

扫描电子显微镜成像信号分析

介绍了扫描电子显微镜（SEM）的基本工作原理,着重分析了在SEM初始电子束作用下,各种成像信号产生的方式及其特点,确定二次电子信号因成像分辨率高、携带成像信息丰富而成为SEM的最终信号源。针对此信号在实际应用中暴露出的缺陷,介绍了解决办法,从而使SEM的成像性能得以大幅提高,使用范围大为扩展。     

Resizing metal-coated nanopores using a scanning electron microscope

Electron beam-induced shrinkage provides a convenient way of resizing solid-state nanopores in Si(3) N(4) membranes. Here, a scanning electron microscope (SEM) has been used to resize a range of different focussed ion beam-milled nanopores in Al-coated Si(3) N(4) membranes. Energy-dispersive X-ray spectra and SEM images acquired during resizing highlight that a time-variant carbon deposition process is the dominant mechanism of pore shrinkage, although granular structures on the membrane surface in the vicinity of the pores suggest that competing processes may occur. Shrinkage is observed on the Al side of the pore as well as on the Si(3) N(4) side, while the shrinkage rate is observed to be dependent on a variety of factors.     

Further scanning electron microscope studies of GaP electroluminescent diodes

In green- and yellow-emitting GaP light-emitting diodes (LEDs) both charge collection (CC), i.e. barrier electron voltaic effect current, and cathodoluminescence (CL) signals were recorded as linescan traces across the p-n junctions. A CL dip was observed in every case, corresponding to the CC peak. This effect could be quantitatively interpreted in terms of the competitive origin of the CC and CL signals. The absence of dips from the CL linescan traces of red LEDs can be explained in terms of the saturation of the CL in these diodes at the beam power levels used in the SEM.     

Applications of the scanning electron microscope in materials science

The commercial manufacture of scanning electron miscroscopes and their introduction into experimental research programmes has led to an increasing appreciation of the application of this type of instrument in materials science. Some account of their employment is presented here, the varying applications indicating clearly the importance of the instrument and its potential for both research and control.     

扫描电子显微镜图像漂移的实时矫正方法

为解决扫描电子显微镜(SEM)由于电子束漂移、电磁干扰等原因导致的图像漂移问题,提出基于ORB结合PROSAC的图像漂移矫正算法。首先采用ORB算法对基准图像和实时图像进行特征检测,然后利用汉明距离与交叉匹配实现特征的初匹配,再结合RANSAC的优化算法PROSAC计算帧间的单应矩阵,利用单应矩阵映射剔除外点后重新迭代计算出最终的精确单应矩阵,最后利用单应矩阵的透视变换实现SEM图像漂移实时矫正。通过实验证明,该算法不仅精度高,而且能够满足SEM实时处理的要求。