Elementary processes in silicon hot wire CVD

The reaction kinetics for the silicon hot-wire chemical vapor deposition (HWCVD) method has been investigated. A time of flight mass spectroscopy (TOF-MS) with a VUV (Vacuum Ultra Violet) single photon ionization technique was used to detect the gas phase chemical species. Si2H6 and Si3H8 were identified as the main gas phase species during the HWCVD film growth processes in the present work. Raman spectra of the deposited films were also recorded to monitor the film properties. Microcrystalline or amorphous films were obtained depending on the experimental conditions, but the mass spectral pattern were almost the same in both microcrystalline and amorphous film growth conditions. A chemical kinetic mechanism for the Si-film growth was discussed on the basis of these observations.