Field effect transistors, integrated circuitry, methods of forming field effect transistor gates, and methods of forming integrated circuitry

摘要

A field effect transistor includes a pair of source/drain regions having a channel region positioned therebetween. A gate is positioned operatively proximate the channel region. The gate includes semiconductive material conductivity doped with at least one of a p-type or n-type conductivity enhancing impurity effective to render the semiconductive material electrically conductive, a silcide layer and a conductive diffusion barrier layer effective to restrict diffusion of p-type or n-type conductivity enhancing impurity. The conductive diffusion barrier layer includes TiW_xN_y. Integrated circuitry is also disclosed.