Microstructure of plasma-deposited a-Si : H films

Abstract

Using transmission and scanning electron microscopy, it is shown that plasma deposition of amorphous silicon hydrogen films from silane or silane/argon mixtures proceeds via nucleation and growth of islands of average lateral dimensions ∼100 Å. If these islands do not coalesce into a homogeneous film, subsequent growth produces columnar morphology with low-density interstitial regions. There is a strong correlation between the columnar structure and the presence of nonradiative recombination centers.