Thin films of silicon dioxide were deposited on (100) Si at low temperatures (room temperature to 375 °C). Oxygen was introduced into the resonance chamber while a dilute silane gas mixture (2% in helium) was fed to a gas ring supported 10 cm above the wafer. Index of refraction, deposition rates, etch rates (for buffered HF), dielectric constant, and oxide breakdown strength were determined as a function of substrate temperature and RF substrate bias. Hydrogen content and Si-O bonding were measured by FTIR spectroscopy. All properties are reported in terms relative to thermally grown oxide.
Film properties improved with increasing substrate temperature and RF substrate bias, sometimes equaling that of thermal oxide. Film quality was the highest for samples deposited at 375 °C, with an applied RF substrate bias.