Silicon wafer surface passivation by low-temperature oxidation prior to ultraviolet radiation for photoconductive decay measurement

Conventionally, wafers are passivated by thermal oxidation at temperatures exceeding 900 degrees C for about an hour prior to effective minority carrier recombination lifetime measurement. This article discusses a method where a reduced duration and low-temperature (650 degrees C) oxidation followed by ultraviolet radiation was found to be efficacious in passivating silicon wafers for photoconductive decay measurements. The effective minority carrier recombination lifetimes of wafers deliberately contaminated with iron, measured by the conventional and the present methods were well correlated. (C) 2000 American Institute of Physics. [S0021-8979(00)04011-1].