A CONTRIBUTION TO THE THEORY OF BEAM-INDUCED CURRENT CHARACTERIZATION OF DISLOCATIONS

A new procedure of calculating the electron-beam-induced current contrast of a crystal defect is presented which yields an exact solution for the contrast of a surface-perpendicular dislocation both in a Schottky diode and in a planar p-n diode. The calculations are based on the bulk recombination model describing a dislocation as a cylindrical inhomogeneity (with radius r(d)) where the total lifetime (tau') is lower than that outside the cylinder. Evaluations of the exact solution for the dependence of the contrast on the electron range show that (i) the input parameters of the model, r(d) and tau', can be consistently determined from the characteristic of the contrast versus the electron range, and (ii) the traditionally used first-order recombination strength is not a generally valid measure of the recombination activity of a surface-perpendicular dislocation.