不同沉积气压制备微晶硅薄膜的表面粗糙度标度行为研究

摘要

The scaling behaviour of surface roughness evolution of microcrystalline silicon（μc-Si：H） films prepared by veryhigh frequency plasma-enhanced chemical vapour deposition（VHF-PECVD） has been investigated by using a spectroscopic ellipsometry（SE） technique.The results show that films deposited at Pg = 70 Pa,the growth exponent β is about.0.22,which corresponds to the definite diffusion growth.However,films deposited at Pg = 300 Pa show abnormal scaling behavior with the exponent β of about.0.81,which is much larger than 0.5 of zero diffusion limit in the scaling theory.This implies that some roughening increasing mechanism such as shadowing effect contributes to the growing surface.%采用VHF-PECVD技术制备了两个气压系列不同生长阶段的微晶硅薄膜,通过椭圆偏振技术研究了生长过程中微晶硅薄膜表面粗糙度的演化.实验结果表明：沉积气压Pg=70 Pa时,生长指数β=0.22±0.023,对应有限扩散生长模式;Pg=300 Pa时,β=0.81±0.099,其超出标度理论中β最大值为0.5范围,出现异常标度行为,表明：在微晶硅薄膜生长中还要考虑其它粗糙化因素（如阴影作用会增加薄膜表面的粗糙化程度,使生长指数β增大）.