Synthesis of microcrystalline silicon thin films using a low-pressure microwave plasma

Microwave plasma (MWP) has been used for the formation of microcrystalline silicon (/spl mu/c-Si:H) thin films since MWP has low electron temperatures, -2.4 eV, and high electron densities, /spl sim/10/sup 10/ cm/sup -3/ (Shirai et al, Jpn. J. Appl. Phys. vol. 37, p. L1078, 1998). Generally in the MWP system, the plasma is not generated stably at a low pressure. In this study, we have developed a new MWP source operating at low pressure. The low pressure MWP will enable us to form the /spl mu/c-Si:H film over a large area. We have investigated the growth of /spl mu/c-Si:H thin films and the effect of dilution gases such as Ar and Xe on film properties at low pressure in SiH/sub 4/-H/sub 2/ MWP. The crystallinity of films was investigated by Raman spectroscopy and X-ray diffraction (XRD). The absolute density of H atoms was evaluated by vacuum ultraviolet absorption spectroscopy (VUVAS). The time-evolution spectra of chemical bonds in the initial film were obtained by in-situ Fourier transform infrared spectroscopy attenuated total reflection (FT-IR ATR).