Infrared spectroscopic study of the reactions between an octadecyltrichlorosilane self-assembled monolayer and plasma

Reactions involving hydrogen plasma and oxygen plasma with a self-assembled monolayer (SAM) of octadecyltrichlorosilane were investigated by infrared absorption spectroscopy in multiple internal reflection geometry. The rate of decrease of the CH3 peak intensity is smaller than that of the CH2 peak intensity when the SAM is exposed to hydrogen plasma. This is attributed to the formation of CH3 components as intermediate states of the hydrogenation of the SAM during hydrogen plasma exposure. Peak intensities due to CH2 and CH3 components in the SAM decreased at the same rate during oxygen plasma exposure. C=O components, detected during plasma exposure, are indicated as the intermediate states of film oxidation.