Cyclic plasma deposition Of SiO2 films at low temperature (80 degrees C) with intermediate plasma treatment

Abstract

Cyclic plasma enhanced chemical vapor deposition (CPECVD) with intermediate O-2 plasma treatment was studied to obtain high quality gate oxide at near room temperature (80 degreesC) using tetraethylorthosilicate (TEOS) and oxygen. SiO2 films were characterized by Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, and secondary ion mass spectroscopy. Periodic O-2 plasma intermediate treatment during oxide deposition was effective in removing the impurities in the oxide film and making the film denser. The Si-OH and carbon impurities in the oxide film decreased with decreasing TEOS/O-2. Current-voltage and capacitance-voltage characteristics were measured for oxide films deposited on silicon wafers. The leakage current density, the interface trap density, and flatband voltage shift were decreased and it was confirmed that high quality silicon dioxide films were obtained at near room temperature with CPECVD along with intermediate O-2 plasma treatment. (C) 2002 American Vacuum Society.