Indentation-induced crystallisation in amorphous silicon thin films

Three amorphous silicon films with different ordering were deposited by magnetron sputtering at 300 K, 673 K and 873 K, respectively. Vickers indentations were made on the samples by loads of 9.8 N, 4.9 N and 0.49 N. Si-I phase was present in the indentations at 9.8 N on the film deposited at 300 K, but evidence for crystallisation into Si-I was less obvious at lower loads at 300 K, or in other films deposited at higher temperatures. The formation of the Si-I phase was probably due to delamination fracture. An increase in the disordering degree induced by indentation was also found in the film deposited at 873 K.