In thin film transistors (TFTs) having an active layer of crystalline silicon adapted for mass production, a catalytic element is introduced into doped regions of an amorphous silicon film by ion implantation or other means. This film is crystallized at a temperature below the strain point of the glass...http://www.google.ca/patents/US6987283?utm_source=gb-gplus-sharePatent US6987283 - Semiconductor device structure
