Hydrogen Passivation of LPCVD Si3N4/SiO2/Si Stacks by Ammonia Plasma Treatment

Abstract

The bonded hydrogen concentration in thermally annealed low-pressure chemical vapor deposition (LPCVD) Si3 N4 films increases rapidly following exposure to ammonia plasma and saturates at a concentration determined by the thermal history of the films. Where the nitride layer is deposited on oxidized silicon samples, the introduction of hydrogen into the nitride film using ammonia plasma is effective at passivating the Si- SiO2 interface. The plasma treatment does not lead to the generation of a significant number of additional interface defects, shown by lifetime and electronic paramagnetic resonance measurements. Subsequent anneals in nitrogen further improve the interface passivation.