Patent ID: 6867074

Claim:
A method of fabricating a polysilicon layer, comprising: providing a substrate; forming a buffer layer over the substrate, wherein the buffer layer includes a plurality of first trenches, wherein the buffer layer comprises a silicon nitride layer and a silicon oxide layer, and the step of forming the buffer layer with the first trenches thereon includes the sub-steps of: forming the silicon nitride layer covering the substrate; forming the silicon oxide layer covering the silicon nitride layer; and forming the first trenches within the silicon oxide layer, wherein a depth of the first trenches does not exceed a thickness of the silicon oxide layer; forming an amorphous silicon layer over the buffer layer, wherein the amorphous silicon layer contacts with the buffer layer at least at a bottom surface of the first trenches, without contacting with the substrate; and conducting a laser annealing process to crystallize the amorphous silicon layer into a polysilicon layer.