Abstract
An EBIC (Electron Beam Induced Current) microscopy system has been set up at the University of Surrey for the first time. Its instrumentation, technical details and use are described. The EBIC mode of the SEM applied to semiconductor multilayer structures showed its potential for defect visualisation. It appears to be especially useful for determining the quality of strained layer samples and the strain relaxation therein. One sample shows a unique white contrast for misfit dislocation lines, which has not been reported previously. A quantitative description of this white contrast with the existing EBIC contrast theory is beyond its range, as a detailed investigation shows. An alternative way for approaching the contrast calculation is possible by employing the Monte Carlo technique for EBIC. With this, an accurate description of the energy dissipated into the sample by the electron beam is achieved. Additionally, the Monte Carlo simulation makes it possible to include getter phenomena into a numerical contrast calculation, which has not been done before. The contrast calculation gives, by assuming a cylindrical getter zone with an increased diffusion length around the misfit dislocation, the same type of contrast and line scan profiles as the observed misfit dislocations. Also, the simulation can make predictions about the geometrical properties of the defects for which a few examples are given.