Properties of nitrogen doped silicon films deposited by low pressure chemical vapour deposition from disilane and ammonia

Abstract

Nitrogen doped silicon films have been deposited by low pressure chemical vapour deposition from disilane Si 2H 6 and ammonia NH 3. Deposition kinetics is investigated, pointing out the influences of the deposition temperature, the total pressure and the gas flow rates. According to the Bruggeman theory, variations of the NH 3/Si 2H 6 gaseous ratio allow for a wide range of the SiN x stoichiometry as well as a good control of the film nitrogen doping. The different behaviours of the nitrogen atom in silicon films are discussed and an overview of the nitrogen doped silicon physical properties (optical, mechanical and electrical) is proposed for the development of boron-doped polysilicon gates.