Improvement of Dielectric Properties on Deposited SiO₂ Caused by Stress Relaxation with Thermal Annealing

Abstract

The relationship between the electrical and structural characteristics of tetraethylorthosilicate (TEOS) SiO2 has been investigated to reveal the mechanism of the improvement of the dielectric properties with thermal annealing. Stress relaxation in TEOS–SiO2 caused by thermal annealing was observed as a blue shift of the infrared absorption spectral peak in a Fourier transform infrared attenuated total reflection (FTIR-ATR) spectrum. It was concluded that the stress relaxation increased the band gap of TEOS–SiO2, resulting in suppression of the leakage current. Additionally, thermal desorption spectroscopy (TDS) performed to investigate the phenomena of film densification by thermal annealing.