Variation of the nanostructural feature of nc-SiC:H thin films with post-deposition thermal annealing

Amorphous silicon carbide (a-SiC) thin films were prepared by plasma enhanced chemical vapor deposition. The films were post-deposition annealed in a N-2-H-2 atmosphere at temperatures ranging from 700 to 1300 degrees C. As the annealing temperature was increased from 1000 to 1300 degrees C, nanocrystalline silicon carbide (nc-SiC) formed and the mean crystallite size varied from similar to 2 to similar to 5 nm. The thermal energy at high annealing temperatures broke the Si-H and C-H bonds, and rearranged the amorphous network to generate local crystalline states, resulting in the formation of nc-SiC. The photoluminescence (PL) peaks varied in the wavelength range of similar to 425 to similar to 470 nm with annealing temperature. The optical band gap of the films has been associated to the maximum PL peak position and estimated to range from similar to 2.92 to similar to 2.64 eV. (C) 2014 Published by Elsevier B.V.