Mechanism of nitrogen coimplant for suppressing boron penetration in p+-polycrystalline silicon gate of p metal–oxide semiconductor field effect transistor

Abstract

The mechanism of the nitrogen co-implant to suppress the boron penetration in p+-polycrystalline silicon gate has been investigated. The nitrogen coimplant with the BF+2 combines with the boron to form a B–N complex which results in a retardation of boron diffusion. It is found that metal–oxide–silicon capacitors with nitrogen implantation show improved electrical properties.