Effects of ratio of hydrogen flow on microstructure of hydrogenated microcrystalline silicon films deposited by magnetron sputtering at 100 °C

Abstract

Hydrogenated microcrystalline silicon (µc-Si:H) films were prepared on glass and silicon substrates by radio frequency magnetron sputtering at 100 °C using a mixture of argon (Ar) and hydrogen (H₂) gasses as precursor gas. The effects of the ratio of hydrogen flow (H₂/(Ar+H₂)%)) on the microstructure were evaluated. Results show that the microstructure, bonding structure, and surface morphology of the µc-Si:H films can be tailored based on the ratio of hydrogen flow. An amorphous to crystalline phase transition occurred when the ratio of hydrogen flow increased up to 50%. The crystallinity increased and tended to stabilize with the increase in ratio of hydrogen flow from 40% to 70%. The surface roughness of thin films increased, and total hydrogen content decreased as the ratio of hydrogen flow increased. All µc-Si:H films have a preferred (111) orientation, independent of the ratio of hydrogen flow. And the µc-Si:H films had a dense structure, which shows their excellent resistance to post-oxidation.

Keywords

hydrogenated microcrystalline silicon films / radio frequency magnetron sputtering / ratio of hydrogen flow / low temperature / microstructure

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