Method of doping a polysilicon layer and semiconductor device obtained.

摘要

A method of uniformly doping arsenic in situ includes forming a semiconductor substrate layer (10) and depositing an optional oxide layer (12) on the semiconductor substrate layer (10). A first doped polysilicon layer (14) is deposited on the oxide layer (12). An undoped polysilicon layer (16) is deposited on the first doped polysilicon layer (14). A second doped polysilicon layer (18) is deposited on the undoped polysilicon layer (16). The polysilicon layers (14), (16), and (18) are annealed such that a dopant within the first polysilicon layer (14) and the second polysilicon layer (18) diffuses throughout all the polysilicon layers in order to form a uniformly doped undivided polysilicon layer (24) on the oxide layer (12).