Highly crystalline intrinsic microcrystalline silicon films using SiF₄/Ar/H₂ glow discharge plasma

We have deposited μc-Si:H films on insulating glass substrates by standard rf glow discharge plasma chemical vapor deposition technique using a mixture of SiF₄, Ar and H₂ at low substrate temperatures. In situ spectroscopic ellipsometry has been used to optimise and elucidate the growth process. Raman spectroscopy, X-ray diffraction, time resolved microwave conductivity and electrical conductivity measurements have been carried out to further characterize the material. Fully crystallized dense μc-Si:H films with no traces of amorphous silicon tissue have been obtained. Under suitable processing conditions fully crystallized films (∼90% large grain and -10% small grain) having a low surface roughness (∼3nm) are produced. Intrinsic character of these films is demonstrated by room temperature dark conductivity of ∼10^-7 Ω^-1cm^-1 with an activation energy of 0.55 eV. The time resolved microwave conductivity measurements show the electron mobilities to be >10 cm²/V.s.