SiO2 thin films were fabricated in an electron cyclotron resonance plasma using tetraethyloxysilane (TEOS) as the silicon source. Oxygen was used as the plasma gas. The film growth rate decreases with an increase of substrate temperature yielding a negative activation energy for the film growth rate. The deposition rate is also dependent on the TEOS flow rate and applied microwave power. These two parameters have significant roles in controlling the film quality. The step coverage characteristics of the film deposited on patterned surfaces are dependent on the substrate temperature. A conformal step coverage on Al wires of 0.5 mu m width and 1 mu m height could be obtained at substrate temperatures over 200 degrees C.