Article ID Journal Published Year Pages File Type
1689582 Vacuum 2014 7 Pages PDF
Abstract

•Nc-Si formation is observed at low temperature via ICP-CVD technique.•Columnar fashion and peculiar structures resembling cauliflower in both a-Si and nc-Si films is clarified with ballistic deposition theory.•Aging effect on the chemical properties is investigated.•High degree time dependent oxidation due to the porous nature of films is observed.

In this study, we report the morphological and structural properties of amorphous and nanocrystalline Si thin films deposited by inductively coupled plasma-assisted chemical vapor deposition (ICP-CVD) technique at low substrate temperatures using H2 diluted SiH4 as the source gas. We demonstrated that changing the total deposition pressure across a broad range alters the film properties. The film grew in a columnar fashion, and its topography was rough at nanoscale as identified by high resolution Transmission Electron Microscopy (TEM), independent of its amorphous or crystalline nature. Further investigation of the structure revealed that the columns consisted of structures resembling highly porous cauliflower. Additionally, these cauliflower-like Si nanostructures oxidized gradually and extremely uniform throughout the film when exposed to air due to their highly porous nature. We have explained the formation of these structural properties using ballistic growth theory and reactive radicals' effect.

Related Topics
Physical Sciences and Engineering Materials Science Surfaces, Coatings and Films
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