SiO[sub 2] Chemical Vapor Deposition at Room Temperature Using SiCl[sub 4] and H[sub 2]O with an NH[sub 3] Catalyst

Silicon dioxide ( SiO 2 ) films were deposited at room temperature using a catalyzed chemical vapor deposition (CVD) reaction. The SiO 2 film growth was accomplished using the reaction SiCl 4 + 2 H 2 O → SiO 2 + 4 HCl and catalyzed with ammonia ( NH 3 ) . The NH 3 catalyst lowered the required temperature for SiO 2 CVD from >900 K to 313–333 K. The ammonia also reduced the SiCl 4 and H 2 O pressures required for efficient SiO 2 CVD from several torr to >500 mTorr. In situ spectroscopic ellipsometry was used to optimize the reactant pressures, catalyst pressure, and reaction temperature. The ellipsometric investigations measured SiO 2 CVD rates that varied from 0.1 Å/min to >16 Å/min depending on temperature and reactant pressures. Rutherford backscattering measurements obtained nearly stoichiometric SiO 2 films with a Si/O ratio of 1:2.1. Atomic force microscopy images displayed a smooth SiO 2 surface topography with a roughness similar to SiO 2 CVD films grown at high temperatures. Catalysis by the NH 3 Lewis base may be general and may facilitate the low temperature CVD of other materials.