Patent ID: 7071049

Claim:
A method of forming a semiconductor device, comprising: forming a first silicon rich barrier layer comprising silicon and nitrogen proximate to a semiconductor substrate; forming a polysilicon film proximate to said first silicon rich barrier layer, wherein said polysilicon film comprises a first region having a first type dopant and a second region having a second type dopant; forming a second silicon rich barrier layer comprising silicon and nitrogen proximate to said polysilicon film; and forming a conductive layer proximate to said second silicon rich barrier layer, wherein: said first silicon rich silicon barrier layer is arranged such that migration of said first and second type dopants from said polysilicon film to said substrate is significantly impeded by said first silicon rich barrier layer; and said second silicon rich silicon barrier layer is arranged such that migration of said first and second type dopants from said polysilicon film to said conductive layer is significantly impeded by said second silicon rich barrier layer.