Fabrication and characteristics of SiOx films by plasma chemical vapor deposition of tetramethylorthosilicate

Silicon oxide films with a low content of carbon residue were deposited by plasma-enhanced chemical vapor deposition with tetramethylorthosilicate (TMOS) as the precursor. With this technique, hard, highly transparent and adherent films can be successfully deposited on glass or poly(methyl-methacrylate) (PMMA) substrates. Influences of plasma parameters such as plasma power, pressure of monomer and Ar plasma post-treatment on the film properties were investigated. Results have shown that the deposition rate of the tetramethylorthosilicate (TMOS) plasma films increased with increasing r.f. power. FTIR spectra of SiOx films deposited from TMOS are very similar to those of pure SiO2. Most of the CHn groups (at 285.4 eV) of TMOS films disappeared and converted to CCO (at 288.6 eV) as observed in the C 1s spectra after Ar plasma treatment. Surface hardness of the films deposited on glass and PMMA substrates is improved to 8H and 4H, respectively. After Ar plasma treatment, the hardness of films deposited on PMMA can be further increased to 6H. The TMOS films also have a high transmission of 90% in the wavelength range from 400 to 800 nm.