J. Phys. Colloques
Volume 42, Numéro C4, Octobre 1981Proceedings of the Ninth International Conference on Amorphous and Liquid Semiconductors
|Page(s)||C4-753 - C4-759|
J. Phys. Colloques 42 (1981) C4-753-C4-759
SURFACE PROPERTIES OF a-Si : H AND a-Si : F INVESTIGATED BY PHOTOELECTRON SPECTROSCOPYL. Ley, H. Richter, R. Kärcher, R.L. Johnson and J. Reichardt
Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, 7000 Stuttgart 80, F.R.G.
It is shown that films of a-Si : H and a-Si : F prepared at room temperature (RT) grow with a surface layer of Si-H3 or Si-F3 largely independent of the bulk distribution of H or F among the possible bonding geometries. This suggests a growth mechanism based on an insertion reaction of SiH2 (F2) into an Si-H (F) bond. Amorphous hydrogenated silicon films are highly resistant to oxidation by dry O2, as compared to c-Si. Activated oxygen is taken up readily and the oxidation leads to the formation of an SiOx layer with an average stoichiometry x that is higher (lower) than that of c-Si for RT (TD = 250°C) a-Si : H. The formation of a depletion layer is observed on the high temperature films.