Characterization of Silicon Oxide Films Deposited from a Permanent-Magnet Helicon Plasma Source

摘要

Silicon oxide films were deposited by an individual PM helicon source using HMDSO as a precursor and N_2O as the reactive gas at low temperature. The chemical structure and elemental composition of the films are characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, and the optical and mechanical properties of the films are evaluated by a thin-film metrology system using reflectance spectra and a nanoindenter. The experimental results show that the N_2O ratio in the plasma has a strong impact on the optical and structural characteristics of the deposited films: with increasing N_2O flow ratios, the hardness of the deposited films increases while the deposition rate and carbon content decreases. At the same time, the characteristics of the oxide films gradually shift away from those of polymers towards those of SiO_2. The technique presented here may find applications in making barrier films for polymer substrates.