Surface properties of silicon oxide films deposited using low-pressure dielectric barrier discharge

The deposition of SiOX films from low-pressure dielectric barrier discharge plasmas has been investigated using tetraethoxysilane (TEOS)/O2 as the feed gas. Films were analyzed using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), AFM-based nanoindentation/nanowear techniques, and conductive AFM. Film deposition rates and hydrocarbon incorporation in the SiOX film decrease with addition of O2. High-quality SiOX films with extremely low surface roughness are deposited at high oxidant concertrations. Addition of oxidant to the feed gas leads to a change in the SiOX film structure from precursor-like to a dense SiOX structure. The SiOX films deposited with TEOS/O2 plasmas were found to have soft surface layers, 0.5-1.5 nm thick, which contribute to an improvement of their field emission properties. The effect of gas phase compositions on the surface properties of the conductive surface layer was discussed.