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

Pasemann [J. Appl. Phys. 69, 6387 (1991)] has recently compared exact and first-order calculations of the charge collection contrast of a straight dislocation perpendicular to the surface of a semiconductor, finding substantially different dependence on the beam energy at low beam energies. Here it is shown that Pasemann's result is only a consequence of having used finite values of the dislocation radius in the exact evaluations and zero in the approximate ones. For nonvanishing dislocation radius, the first-order approximation reproduces the exact contrast trend at any beam energy.