Digital electron beam induced current imaging: Apparatus and analysis

Abstract

The electron beam induced current (EBIC) method is a well known technique for studying charge carrier recombination at extended defects in semiconductors. In this work a new electron beam induced current apparatus is described. It employs computer automated measurement and control equipment to acquire high resolution beam induced current images using a conventional secondary electron microscope. The electron beam induced current images typically contain a matrix of 512×512 digitally measured points. They can be displayed on a workstation monitor and imaging processing can be performed. The increased current resolution of the apparatus necessitated the modification of traditional quantitative EBIC analysis methods. The modified quantitative analysis method is presented and applied to the problem of precipitates contained in a Czochralski silicon solar cell. It results in a characterization of the amount of charge carrier recombination at the defects and a calculation of the depth of the defects below the sample surface.