Supercritical Fluid Deposition of SiO2 Thin Films: Growth Characteristics and Film Properties

Supercritical fluid deposition (SCFD) of SiO2 thin film using supercritical fluid CO2 (SCF CO2) was investigated. Tetraethyl orthosilicate (TEOS) and O-2 were used as precursor and reactant, respectively. Growth characteristics of SCFD SiO2 were investigated as a function of key growth parameters including the concentration of precursors, deposition time, and temperature. The activation energy of SCFD SiO2 was lower than the reported value of chemical vapor deposition of SiO2, indicating the solvation effects of SCF CO2 on the reaction of TEOS and O-2. By controlling precursor concentrations, excellent gap filling of SCFD SiO2 was achieved even inside of anodic aluminum oxide with less than 50 nm hole diameter. Leakage current of SCFD SiO2 films increased with increasing oxygen concentration, which was attributed to the decrease of the film density. Higher O-2 concentration led to rapid reaction of SCFD SiO2, resulting in the low density SiO2 formation with high leakage current. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.031202jes] All rights reserved.