Interaction of water with silicon dioxide at low temperature relevant to CMP

The reaction of water with silicon dioxide to form silanol species has been proposed to be a major component of the silicon dioxide chemical mechanical penalization (CMP) mechanism. Internal-reflection infrared spectroscopy was used to examine this reaction at low temperatures relevant to CMP of silicon dioxide thin films during integrated circuit manufacture (20-80°C). No significant reaction was observed at 20°C; some silanol formation was observed at 80°C with long exposure times. Molecular water was the predominant hydrous species observed at 80°C indicating that silanol formation does not contribute as significantly to the CMP removal process as previously thought.