Cleaning and Doping of Silicon in a BF3Plasma during Fabrication of Ohmic Contacts

Abstract

The formation of reliable ohmic contacts to silicon is considered. Silicon surface cleaning, contact window doping, and molybdenum application by cathode sputtering in the BF3atmosphere are carried out in a single vacuum cycle. A model of semiconductor–plasma and dielectric–plasma contacts under stationary discharge conditions is discussed. It is shown that the rates of processes with the participation of charged particles on p-Si and n-Si surfaces substantially differ. The resistivity of Mo-n + Si and Mo-p + Si contacts is the least when the molybdenum films are applied by sputtering in the Ar + (10–15) vol % BF3atmosphere.