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.