Atomic-Layer-Deposition of SiO2 with Tris(Dimethylamino)Silane (TDMAS) and Ozone Investigated by Infrared Absorption Spectroscopy

We have studied SiO2 ALD processes with precursors of tris(dimethylamino)silane (TDMAS) and ozone on Si(100) surfaces at room temperature by infrared absorption spectroscopy with a multiple internal reflection geometry. It was found that TDMAS dissociatively adsorbs on OH sites of hydroxyrated Si surfaces and ozone irradiation is effective to remove the hydroaminocarbon adsorbates introduced in the course of the TDMAS adsorption. Compensation of OH sites by a water vapor treatment after the ozone process is effective to sustain the cyclic SiO2 deposition.