PROCESS FOR DEPOSITING HIGHLY DOPED POLYSILICON LAYER ON STEPPED SURFACE OF SEMICONDUCTOR WAFER RESULTING IN ENHANCED STEP COVERAGE

摘要

A polysilicon deposition process is disclosed for forming a doped polysilicon layer over a stepped surface (40, 50) on a semiconductor wafer (30) having the deposition characteristics and resulting profile of an undoped polysilicon layer which comprises: depositing doped polysilicon (60) on the stepped surface (40, 50) depositing undoped polysilicon (70) over the doped polysilicon, repeating the doped and undoped depositions cyclically until the desired amount of polysilicon has been deposited, and then annealing the deposited polysilicon to uniformly distribute the dopant throughout the entire deposited polysilicon layer. IMAGE