Role of SiH4 gas heating in the growth of hydrogenated microcrystalline silicon

The effect of SiH4 source gas heating on the early stage of growth of hydrogenated microcrystalline silicon (mu c-Si:H) by plasma-enhanced chemical vapor deposition (PECVD) from SiH4 and H-2 has been investigated to improve the film crystallinity and inhomogeneities. The crystallinity is improved without increasing the surface roughness on thermally grown SiO2 when the cathode temperature, T-c, is greater than 500 degrees C. The major role of SiH4 gas heating is not only to increase the temperature of the growing surface but also to the thermally activate the deposition precursors on the growing surface and/or to generate polymerized precursors in the gas phase.