¹V. Lashkaryov Institute of Semiconductor Physics, 03028 Kyiv, Ukraine
²Japan Fine Ceramics Center, Nagoya, 456-8587 Japan

Abstract. Near-stochiometric and carbon-rich a-Si_1−xC_x:H thin films were deposited using the magnetron sputtering of Si target in Ar/CH₄ gas mixture. As-deposited near-stochimetric (x = 0.5) sample showed weak blue photoluminescence (PL), while PL of as-deposited carbon-rich (x = 0.7) sample was white in color and 20 times stronger. The films were annealed in pure argon, wet argon, and dry oxygen at 450 °C for 30 min. The intensity of white PL in a-Si_1−xC_x:H layers were enhanced by the factor from 2 to 12 after annealing in dependence on the annealing atmosphere. The strongest oxidation and strongest white light emission were observed in carbon-rich series (x = 0.7) after annealing in oxidizing atmosphere. Structural properties of the films were characterized by infra-red absorption spectroscopy (FTIR), ellipsometry and electron paramagnetic resonance (EPR). The effect of a-Si_1−xC_x:H carbon enrichment of films and annealing atmosphere on the evolution of photoluminescence and local interatomic bonding structure in annealed material were studied and analyzed. It has been found that main effects of thermal treatments is strong enhancement of photoluminescence accompanied by formation of Si:C−H_n and Si−O_xC_y bonding. The strongest oxidation effects as well as strongest white photoluminescence were observed in carbon-rich a-SiC:H films.

Keywords: a-Si_1−xC_x:H, ellipsometry and electron paramagnetic resonance, photoluminescence, infra-red absorption spectroscopy.

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