Automatic detection of defect positions including interface dislocations and strain measurement in Ge/Si heterostructure from moire phase processing of TEM image

摘要

An automatic detection method of crystal defect positions including interface dislocations and a strain imaging method for an arbitrarily oriented atomic array were developed based on the sampling moire technique. An automatic defect location detection algorithm was proposed by defining a defect detection coefficient. As an application, a transmission electron microscope (TEM) image of a Ge/Si crystal structure was investigated, and the atomic arrays including defects were in-situ amplified in a large field of view. The locations of defects and interface dislocations were automatically detected. The strain distribution of this structure was presented and the complex interface curve was plotted. All the positions and atom distribution trends of common dislocations in Ge and Si arrays, and the Ge/Si interface dislocations were verified successfully from the enlarged TEM images. These dislocations were caused by the mismatch between n-column and (n-1) or (n+1)-column homogeneous or heterogeneous atoms, where n is an integer greater than two. This study provides a useful way for characterizing crystal defects and strain distribution in semiconductors and metals.