Defect Reduction Treatment for Plasma-Tetraethylorthosilicate-SiO_2 by High-Pressure H_2O Vapor Heat Treatment

摘要

Improvements in the electrical and structural properties of tetraethylorthosilicate (TEOS) SiO_2 films fabricated by plasma-enhanced chemical vapor deposition (PECVD) method were investigated using high-pressure H_2O vapor heat treatment. The density of interface trap states was reduced from 3.3 x 10~(12) (initial) to 5.1 x 10~(10) cm~(-2) eV~(-1) by 1.3 x 10~6 Pa H_2O vapor heat treatment at 260℃ for 9 h. The density of fixed charges was also reduced from 6.1 x 10~(11) to 1.3 x 10~(11) cm~(-2). The full width at half-maximum (FWHM) of the optical absorption band corresponding to vibration of Si-O-Si bonding was reduced from 82.9 to 78.1 cm~(-1). Narrowing in FWHM of the Si 2p core level peak measured by X-ray photoelectron spectroscopy (XPS) was also observed. The reduction in the FWHM probably results from improvement of the Si-0 bonding network.