Method for forming trenched polysilicon structure

摘要

A method for forming a trenched polysilicon structure can be applied to a semiconductor device. The method includes steps of: a) providing a polysilicon layer; b) forming a dielectric layer on the polysilicon layer; c) forming a rugged oxide layer on the dielectric layer; d) removing a portion of the dielectric layer which is not covered by the rugged oxide layer for exposing a corresponding portion of the polysilicon layer; e) forming a plurality of microtrenches by etching the corresponding portion of the polysilicon layer; and f) removing the rugged oxide layer and the dielectric layer to obtain the trenched polysilicon structure.