Effects of Nitrogen Implantation on Oxide Growth and Quality

The effects of implanting nitrogen prior to gate oxidation are presented. Three different doses of N+, N2+, and Si+ were implanted, followed by a 20- minute 950°C dry oxide growth. Growth rate, interface quality and breakdown strength were measured. Results show up to a 70% reduction in growth rate for high dose nitrogen implants, but no change for silicon implants. The interface trap density decreased with increasing dose for all three species. Oxides grown over N2+ implanted silicon showed field strengths comparable to standard oxides