Method for forming polycrystalline semiconductor layer

A method for forming a polycrystalline semiconductor layer includes forming a plurality of spacers over a dielectric layer, etching the dielectric layer using the plurality of spacers as an etch maskto form a recess in the dielectric layer, depositing an amorphous semiconductor layer over the plurality of spacers and the dielectric layer to fill the recess, and recrystallizing the amorphous semiconductor layer to form a polycrystalline semiconductor layer. 一种多晶半导体层的制造方法包含形成多个间隙壁在介电层上、利用间隙壁做为蚀刻罩幕蚀刻介电层，以形成凹槽在介电层内、沉积非晶半导体层在间隙壁及介电层上，以填充凹槽，以及再结晶非晶半导体层，以形成多晶半导体层。