Chemical deposition of silica-based thin films under supercritical carbon dioxide atmosphere using tetraethylorthosilicate precursor with oxidizing agents

Supercritical fluid deposition (SCFD) of SiO2-based films was proposed using TEOS precursor with oxidizing agents, for the purpose of low-temperature film deposition. The film deposition was performed in a batch-type closed chamber filled with supercritical carbon dioxide (CO2) fluid. The SiO2-based films were deposited on aluminum electrodes coated on silicon wafers (Al/Si) at the substrate temperature above 150°C. Oxidizing agents such as O2 gas and aqueous H2O2 solution promoted the removal of C2H5OH byproduct and the formation of strong Si-O network, whereas it also promoted the homogeneous nucleation of granular precipitation and the H2O adsorption in/on the resulting films. The processing temperature of the SCFD was significantly lower than those by thermal CVD and comparable or higher than those by plasma-enhanced CVD, although the resulting films obtained exhibited relatively large dielectric loss which depends on the presence of C2H5OH and H2O byproducts.