Electrical properties of bulk silicon dioxide and SiO2/Si interface formed by tetraethylorthosilicate (TEOS)-oxygen plasma enhanced chemical vapor deposition

Abstract

The electrical properties of bulk silicon dioxide and the SiO2/Si interface formed by TEOS/O-2 PECVD were investigated. Additionally, the gas phase in the glow discharge was investigated using OES analysis under various experimental conditions. Changes of TEOS/O-2 ratio and the deposition temperature influenced the electrical properties of silicon oxide films. With decreasing TEOS/O-2, ratio, the electrical properties of bulk silicon dioxide and the SiO2/Si interface were improved. This is thought to be due to the decrease of carbon impurity in the growing oxide film. At higher deposition temperatures, the oxide films had good electrical properties, which is thought to be due to the change of structure in the oxide film. From C-V analysis for all experimental conditions, the P-b center defects were observed near E-v+0.25eV and E (v)+0.73eV in the Si band gap. The magnitude was influenced by process parameters such as the TEOS/O-2 ratio and the deposition temperature. From OES analysis, the main emission peaks observed in the glow discharge were from CO, CO2+, CH, and C. With decreasing TEOS/O-2 ratio, the emission intensity of CH decreased and that of CO increased. (C) 2000 Kluwer Academic Publishers.