Abstract: Deep profile and highly doped impurity regions can be formed by diffusing from a solid source or doped silicon glass and using a patterned nitride layer. An oxide etch stop and polysilicon sacrificial layer are left in place in the patterned regions and the dopant is diffused through those layers. The polysilicon provides sacrificial silicon that serves to prevent the formation of boron silicon nitride on the substrate surface and also protects the oxide layer during etching of the silicon glass layer. The oxide layer then acts as an etch stop during removal of the polysilicon layer. In this way, no damage done to the substrate surface during the diffusion or subsequent etch steps and the need for expensive ion implanter steps is avoided.