Nanocrystalline Silicon Thin Films Fabricated at 80°C by Using Electron Cyclotron Resonance Chemical Vapor Deposition

Deposition of nanocrystalline silicon (nc-Si) on glass at very low temperatures by electron cyclotron resonance (ECR) plasma enhanced chemical vapour deposition (PECVD) was investigated. It was shown that nc-Si could be deposited from hydrogen diluted silane gas at a substrate temperature of 80 degrees C with a crystalline fraction up to 80% and a lateral grain size of around 50 nm. This was achieved by growing the nc-Si in a low pressure regime which ensured that mono-silyl species were the dominant deposition precursor. Furthermore, a high flux of energetic hydrogen ions was required to induce crystallisation of the silicon material through a chemical annealing process.