The influence of the generation volume of minority carriers on EBIC

Abstract

Analysis of electron-beam-induced current (EBIC) in the line scan method is described in the case of finite generation volume. The influence of surface recombination on EBIC is investigated, when the three-dimensional generation distribution is taken into account. When the accelerating voltage V_a of an electron beam is low, the generation volume is assumed to be a point; surface recombination has a great effect on the shapes of curves of EBIC versus scanning distance and on the absolute value of EBIC. When V_a becomes high, the generation volume can no longer be assumed to be a point; surface recombination does not affect the shape of EBIC versus scanning distance curves, but reduces the absolute value. The existence of a maximum value of EBIC near the barrier can be explained by an analysis using the finite generation volume. Accurate values of the physical parameters such as the diffusive length are estimated by fitting the experimental data to the theoretical curves for all accelerating voltages.