The effects of deposition temperature on properties of SiO2 films fabricated by a new electron cyclotron resonance microwave plasma-enhanced chemical-vapor deposition process

Silicon dioxide (SiO2) films were deposited by a new electron cyclotron resonance (ECR) microwave plasma enhanced chemical vapor deposition (PECVD) process at various deposition temperatures ranging from room temperaure (~25 °C) to 300 °C. The deposition rate increases with increasing deposition temperature and tends to become saturated as the deposition temperature approaches 250 °C, in contrast to the SiO2 films fabricated by the conventional ECR microwave PECVD process. The Fourier transform infrared results provide no evidence of hydrogen incorporation in the SiO2 films even when they were deposited at room temperature. Films deposited at temperatures higher than 270 °C exhibit an excellent electrical integrity that is comparable with high-quality SiO2 films grown thermally at 1000 °C. Films deposited at room temperature have a slightly higher refractive index and also high-leakage current though the films appear as good as those deposited at 300 °C. As the deposition temperature is increased, both the shoulder height of the Si—O stretching band and the leakage current decrease. The correlation between the film properties and the film growth mechanism is also discussed.