Combinatorial deposition of microcrystalline Si films using multi-hollow discharge plasma CVD

Recently, we have developed a multi-hollow discharge plasma CVD method by which fluxes of H and SiH$_{3}$ radicals and their flux ratio on a substrate can be varied with a distance $z$ from the discharge region. In this study, we deposited Si films with different structures n a combinatorial way and evaluated $z$ dependence of the film crystallinity by laser Raman spectroscopy. Films were deposited using the multi-hollow discharges of H$_{2}$+SiH$_{4}$ (0.33{\%}) for a gas pressure $P$ Spatial profile of the deposition rate and the crystallinity significantly depend on z For $P$= 2 Torr, no films are deposited just near the discharges due to Si etching by H, $\mu$c-Si films are deposited for z= 3 - 32 mm. For $P$=6 Torr, $\mu$c-Si films are deposited in a narrow region for z= 0 - 7 mm. These results indicate that the spatial profile of the flux ratio of H to SiH$_{3}$ strongly depends on the gas pressure and a process window of microcrystalline Si films becomes quite narrow at a higher gas pressure