Study on crystallization of hydrogenated nanocrystalline silicon carbon films

Abstract

Hydrogenated nanocrystalline silicon carbon (nc-SiC x :H) films were prepared by RF glow discharge of gas mixture of silane (SiH 4) and ethene (C 2H 4) diluted heavily by hydrogen (H 2). The effect of the gas volume ratio of (SiH 4 + C 2H 4)/H 2 ( X g) and C 2H 4/(SiH 4 + C 2H 4) ( X c) on the crystallization and composition of films are described in the paper. When the X g 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 X g ≥ 6%, the deposited films of hydrogenated amorphous silicon carbon are formed. When X c 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 X c ≥ 0.5, the deposited films are hydrogenated amorphous silicon carbon films. The growth process and crystallization mechanism of nc-SiC x :H films are discussed in detail.