Study on crystallization of hydrogenated nanocrystalline silicon carbon films

Hydrogenated nanocrystalline silicon carbon (nc-SiCx:H) films were prepared by RF glow discharge of gas mixture of silane (SiH4) and ethene (C2H4) diluted heavily by hydrogen (H2). The effect of the gas volume ratio of (SiH4 + C2H4)/H2 (Xg) and C2H4/(SiH4 + C2H4) (Xc) on the crystallization and composition of films are described in the paper. When the Xg increases from 2 to 5%, the volume fraction of the crystalline phase decreases from 48 to 8% and the mean crystallites size is varied from 3.5 to 9 nm because the etching effect of hydrogen becomes weak. When Xg ≥ 6%, the deposited films of hydrogenated amorphous silicon carbon are formed. When Xc increases from 0.1 to 0.4, the volume fraction of the crystalline phase decreases from 45 to 10%, the mean crystallites size decreases from 10 to 5.5 nm, and the C content of the films increases from 0.03 to 0.12. When Xc ≥ 0.5, the deposited films are hydrogenated amorphous silicon carbon films. The growth process and crystallization mechanism of nc-SiCx:H films are discussed in detail.