Thermal stability and dopant drive-out characteristics of CoSi2 polycide gates

Abstract
BF2‐implanted CoSi2 polycide gates that are stable at high temperatures up to 1000 °C have been fabricated. The use of CoSi2 polycide as a boron diffusion source was evaluated using a metal‐oxide‐semiconductor capacitor structure on a p‐type Si substrate. This structure is useful in monitoring the diffusion of the electrically activated dopants from the silicide towards the polycrystalline silicon‐SiO2 interface. Our results show that using BF2‐implanted CoSi2 as a diffusion source is effective in doping polycrystalline silicon gates degenerately without any degradation of the polycide resistivity.