Conversion from helium to nitrogen as a TEOS carrier gas in sub-atmospheric chemical vapor deposition

We have investigated the influence of TEOS carrier gases on deposition characteristics and characteristics of silicon oxide films deposited by sub-atmospheric chemical vapor deposition (SACVD). We revealed that the deposition rates varied and the film-thickness uniformity was degraded as the TEOS carrier gas was converted from helium to nitrogen. However the film-thickness uniformity was able to be improved by optimizing the gas pressure. The silicon oxide films deposited with the TEOS carrier gases of nitrogen and helium were found to have almost equal refractive index, water amount in the film, OH bond amount, wet etch rate, shrinkage, and elastic modulus. Therefore we successfully converted from helium to nitrogen as the TEOS carrier gas in the SACVD, leading to the reduction of the cost of the TEOS-O₃ film deposition.