【摘要】 用200 kV六硼化镧灯丝的高分辨电子显微镜拍摄了外延生长在硅衬底的3C-SiC薄膜的[110]显微像。经过解卷处理和衍射振幅校正,把实验像转换为直接反映晶体投影结构的结构像,近邻Si、C原子柱显现为黑(灰)的像点对,即所谓的哑铃。测量了结构像中不同厚度区域哑铃的灰度变化,分析了哑铃中二个端点的相对灰度值随厚度的变化关系,结合赝弱相位物体近似像衬理论进行分析,辨认出Si与C原子柱。更多还原

【Abstract】 The image of 3C-SiC film grown on Si substrate was taken with a 200 kV high-resolution electron microscope equipped with the LaB6 filament.By performing the image deconvolution and diffraction amplitude correction the experimental image was transformed into the structure image that directly represents the projected crystal structure.The adjacent Si and C atomic columns reveal themselves as pairs of black/gray dots,i.e.the so called dumbbells.The gray levels of dumbbells in the structure image were measured for regions of different thickness,and the variation of relative gray level with crystal thickness for the two ends in dumbbells were obtained.Then the Si and C atomic columns can be distinguished by an analysis based on the contrast theory of pseudo weak-phase object approximation.更多还原