乙烯对纳米硅碳薄膜晶化的影响

EFFECT OF ETHENE TO THE CRYSTALLIZATION OF NANOCRYSTALLINE SILICON CARBON FILMS

在等离子体化学气相沉积系统中采用高氢稀释硅烷加乙烯法制备了ｎｃ－ＳｉＣｘ∶Ｈ薄膜。系统研究了Ｃ２Ｈ４／（Ｃ２Ｈ４＋ＳｉＨ４）（Ｘｃ）气体流量比对ｎｃ－ＳｉＧｘ∶Ｈ薄膜的晶化和其它光电性能的影响。Ｘｃ从０．１增加为０．４时，薄膜的晶态率从４５％下降为１０％，平均晶粒尺寸从１０ｎｍ下降为５．５ｎｍ，对应薄膜中的Ｃ含量从０．０３增加为０．１２。当Ｘｃ≥０．５，生成薄膜为非晶硅碳（ａ－ＳｉＣｘ∶Ｈ）薄膜。随着Ｘｃ从０．１增加为０．８，薄膜的暗电导率从８．５×１０－７（Ωｃｍ）－１下降为９×１０－１２（Ωｃｍ）－１，薄膜的光学能隙随Ｘｃ的增加而增加。

Nanocrystalline silicon carbon films were prepared by rf glow discharge of heavily H2 diluted SiH4 and C2H4. The effect of gas volume ratio of C2H4/(C2H4+SiH4) (Xc) to the films crystallization and other properties have been studied. The volume fraction of the crystalline phase is decreased from 45% to 10% when the Xc is increased from 0. 1 to 0.4 and the mean crystallites size is decreased from to 5.5nm, connected with the C content increasing from 0.03 to 0. 12. When Xc≥0.5,the deposition films are amorphous silicon carbon films. The dark conductivity of SiC films are decreased from 8.5 ×10-7 (Ωcm)-1 to 9× 10-12 (Ωcm)-1 with the increasing of Xc from 0. 1 to 0.8. The optical energy gap is increased with the moresing of Xc from 0.1 to 0.8. The optical energy gap is increased with the increasing of Xc.