Formation of silicon nitride layers by nitrogen ion irradiation of silicon biased to a high voltage in an electron cyclotron resonance microwave plasma

Abstract

Silicon was pulse biased to −50 kV in a nitrogen plasma generated by microwave excitation in electron cyclotron resonance mode. Nitrogen ions from the plasma were accelerated in the electrical field and implanted into the silicon. Cross-section transmission electron microscopy showed that the resulting surface layer was amorphous. Tempering at 1500 K led to the formation of a 25 nm thick continuous crystalline film of α-Si3N4 buried under a 50 nm thick amorphous surface zone.