Nitridation of the stacked poly-Si gate to suppress the boron penetration in pMOS

Nitridation to create nitrogen-rich layers in-between the stacked layers of the poly-Si gate to suppress the boron penetration for pMOS with the gate BF/sub 2//sup +/-implantation is proposed and demonstrated. The MOS capacitors fabricated by using this nitridized stacked poly-Si gate have better thermal stability and much improved electrical characteristics.