화학공학소재연구정보센터
Journal of Vacuum Science & Technology A, Vol.19, No.4, 2013-2016, 2001
Near-edge valence-band structure of amorphous hydrogenated Si-C thin films characterized by Auger and photoemission processes
A core-valence-valance Auger transition contains information about the local valence electronic structure of the probed atom. This is due to the direct coupling of the core and valence levels involved in the Auger process. In this work. a combined use of the Auger and photoemission processes to study near-edge valence-band structures of amorphous hydrogenated silicon carbide is described. Experimentally, a-Si1-xCx:H thin films were fabricated by plasma-enhanced chemical-vapor deposition using methylsilane precursors. Hydrogen was incorporated in the plasma to control the carbon composition from 0.36 to 0.83. The valence-band edge in the Si-rich region (x <0.6) was lead by both Si 3p and C 2p states, while the C 2p states from the C-C bonding configuration dominates the near-edge structure in the C-rich region (x greater than or equal to0.6). Due to the large difference in the photoionization cross sections for Si 3p and C 2p, the valance spectrum measured from x-ray photelectron spectroscopy failed to represent the near-edge structure in a-Si1-xCx:H.