Accurate measurement of extremely low surface recombination velocities on charged, oxidized silicon surfaces using a simple metal-oxide-semiconductor structure

Abstract

The authors report a simple technique to determine the surface recombination velocity of silicon and other semiconductor surfaces which have been passivated with a dielectric layer, as a function of charge density. A metal-oxide-semiconductor structure, employing large area, partially transparent metal contacts, is used to enable the charging of the surfaces. Simultaneous measurement of the emitter saturation current density Joe and the effective instantaneous lifetime τinst allows accurate extraction of the effective surface recombination velocity Seff at any given injection level. Extremely low Joe values of 1.8fAcm−2 are measured on the silicon-silicon oxide (Si–SiO2) interface of a thermally oxidized, charged wafer.