Abstract
The intensities of emission from N2+ and NH radicals in Ar/N2, Xe/N2 Ar/NH3 or Xe/NH3 plasma excited by microwave and the chemical bonding states of nitrogen atoms in silicon oxynitride film nitrided by using these plasmas were investigated. Depth profiles of composition and chemical structures in the oxynitride films were investigated by X-ray photoelectron spectroscopy combined with step etching in HF solution. The emission intensities from N2+ radical generated in Xe/N2, Ar/NH3 or Xe/NH3 plasma are less than a quarter of that from N2+ radical generated in Ar/N2 plasma. The emission from NH radical detected in Ar/NH3 or Xe/NH3 plasma is not detected in Xe/N2 or Ar/N2 plasma. The order of the nitrogen concentration near the film/substrate interface is Ar/NH3>Xe/NH3>Ar/N2>Xe/N2 plasma. Therefore, it is important for the reduction of the nitrogen concentration near the film/substrate interface to use Xe/N2 plasma in which both of the generation efficiencies of N2+ and NH radicals are low.
