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.de/patents/US7391051?utm_source=gb-gplus-sharePatent US7391051 - Semiconductor device forming method
