The effect of nitrogen in p+ polysilicon gates on boron penetration into silicon substrate through the gate oxide

The effects of in-situ doped or implanted nitrogen in p+ polysilicon gates on boron penetration into silicon substrate through the gate oxide have been investigated. It is confirmed that the decrease in the boron diffusivity in the interior of polysilicon gate rather than the nitrogen pile-up or changes in the segregation coefficient at the polysilicon/SiO/sub 2/ interface is responsible for the retardation of boron penetration.