Investigation of cryogenic dry etching of silicon on I-V curves of Schottky diodes

I-V characteristics of silicon wafer with Schottky contacts were investigated to find out influence of dry plasma etching on defects emerging in the structure. Wafer was divided into two pieces, one of them has affected to cryogenic etching using SF₆/O₂ (in ratio 5:1) and a pressure 5 mTor for two minutes. The second part of the wafer was used as a reference. It was founded, that for the same contact diameters, etched samples demonstrate higher slope of the I-V curve at the direct voltage. A similar effect was observed in the case of the existence of a defective near-surface region, where carrier recombination is enhanced, which results a significant increase in the direct current. (paper)