Patent ID: 7507648

Claim:
A method of crystallizing an amorphous silicon (a-Si) comprising the steps of; a) depositing an undoped or lightly-doped a-Si layer on a substrate; b) forming a heavily doped a-Si layer having a doping concentration of at least 10 19 cm −3 on or in said undoped or lightly doped a-Si layer; and c) annealing at elevated temperature to crystallize said undoped or lightly-doped a-Si layer at a thermal budget below that which would crystallize said undoped or lightly doped silicon layer without the heavily doped a-Si thereon, such that the crystallization starts from the heavily doped a-Si layer and continues to crystallize the undoped or lightly doped a-Si layer; wherein the annealing step (c) is performed in the presence of an oxidizing ambient.