Calculation of the electron-beam-induced current (EBIC) at a Schottky contact and comparison with Au/n-Ge diodes

Abstract

Abstract The electron-beam-induced current (EBIC) collection efficiency n of a Schottky contact perpendicular to the electron beam of a scanning electron microscope is calculated. The continuity equation is solved for a non-uniform generation function assuming a linear variation of the electric field within the depletion zone. The recombination of the carriers at the metal-semiconductor interface is considered. Majority carrier injection from the semiconductor into the metal is found to be non-negligible for low doping level and low beam energy. It is demonstrated that the assumption of 100% collection efficiency for the minority carriers generated within the depletion zone, and the related boundary condition, lead to an overestimation of the collected EBIC intensity, particularly for short minority diffusion lengths. The present model allows a more satisfactory analysis of the experimental data obtained on Au/n-Ge Schottky contacts.