Effect of ion bombardment on the a-Si:H based surface passivation of c-Si surfaces

We have found that controlled Ar ion bombardment enhances the degradation of a-Si: H based surface passivation of c-Si surfaces. The decrease in the level of surface passivation is found to be independent on the ion kinetic energy (7-70 eV), but linearly proportional to the ion flux (6 X 10(14)-6 X 10(15) ions cm(-2) s(-1)). This result suggests that the ion flux determines the generation rate of electron-hole pairs in a-Si: H films, by which metastable defects are created at the H/a-Si:c-Si interface. Possible mechanisms for the ion induced generation of electron-hole pairs are discussed. (C) 2011 American Institute of Physics.