Patent attributes
Method of fabricating polysilicon film includes forming insulating layer, first amorphous silicon layer, and cap layer over a substrate. An annealing is performed to transform the first amorphous silicon layer into first polysilicon layer with at least a hole. The cap layer is removed. A portion of the insulating layer within the hole is removed to form first opening within the insulating layer. The hole and the first opening constitute a second opening. A dielectric layer is formed over the first polysilicon layer. The dielectric layer also fills the second opening, causing a recess on the dielectric layer above the second opening. A second amorphous silicon layer is formed over the dielectric layer. A second annealing is performed to transform the second amorphous silicon layer into a second polysilicon layer. The second opening induces a thermal difference so as to cause a crystallizing direction for the second amorphous silicon layer.
