ADSORPTION-KINETICS STUDIES OF CHLOROSILANES ON SILICON

Molecular layers are formed on hydroxylated silicon wafer (100) upon a dsorption of dimethyldichlorosilane (DMS), diphenyldichlorosilane (DPS ) and triphenylchlorosilane (TPS) from CCl4 solution. The chemisorbed silane films are characterised by Infrared and High Resolution Electro n Energy Loss (HREEL) spectroscopies. The multi-internal reflection (M IR) technique is carried out in situ and allows the comparison of adso rption kinetics of DMS and DPS. These deuterated corresponding molecul es are used to control eventual contamination. The IR experiments show the consumption of physisorbed water and surface hydroxyle groups and the increase of methyl or phenyl groups during the adsorption of resp ectively DMS and DPS. DMS adsorption gives reproducible controlled lay er on silica surface while DPS or TPS adsorptions lead to the growth o f successive multilayers.