Room Temperature Growth of Hydrogenated Amorphous Silicon Films by Dielectric Barrier Discharge Enhanced CVD

Abstract

Hydrogenated amorphous silicon (a-Si: H) films were deposited on Si (100) and glass substrates by dielectric barrier discharge enhanced chemical vapour deposition (DBD-CVD) in (SiH4+H2) atmosphere at room temperature.Results of the thickness measurement, SEM (scanningelectron microscope), Raman, and FTIR (Fourier transform infraredspectroscopy) show that with the increase in the applied peakvoltage, the deposition rate and network order of the filmsincrease, and the hydrogen bonding configurations mainly indi-hydrogen (Si-H2) and poly hydrogen (SiH2)n are introducedinto the films. The UV-visible transmission spectra show that withthe decrease in SiH4/ (SiH4+H2) the thin films' band gapshifts from 1.92 eV to 2.17 eV.These experimental results are in agreement with thetheoretic analysis of the DBD discharge. The deposition of a-Si: Hfilms by the DBD-CVD method as reported here for the first time isattractive because it allows fast deposition of a-Si: H films onlarge-area low-melting-point substrates and requires only a low costof production without additional heating or pumping equipment.