High rate deposition of silicon nitride films by APCVD

Silicon nitride films have been prepared by atmospheric pressure chemical vapor deposition (APCVD) on moving glass substrates from a gas mixture of monosilane, ammonia and nitrogen. The CVD reactor system used in this work is similar to those used in APCVD during a float glass production process (on-line CVD). At the substrate temperature of 830 deg. C, we prepared silicon nitride films and the deposition rate was over 10 nm/s. The deposition rates measured are not high enough at the temperatures typical of most on-line processes (650-750 deg. C). The deposition rate and the characteristics of silicon nitride films have been investigated using ellipsometry, X-ray photoemission spectroscopy (XPS) and Rutherford backscattering spectroscopy (RBS). The obtained film is transparent and the refractive index at the wavelength of 550 nm is 1.90-1.97. The film composition depends on the ratio of NH3 to SiH4 in the source gas and the hydrogen concentration is approximately 15%. It seems that hydrogen atoms incorporated in the film affect properties of the films