Polysilicon gate having a metal plug, for reduced gate resistance, within a trench extending into the polysilicon layer of the gate

摘要

A device and method to reduce resistance in polysilicon gates by forming a highly conductive plug within a trench in the gate. This is achieved by etching a trench between nitride sidewalls and into the polysilicon layer and depositing a metal (e.g. tungsten) plug therein. Certain embodiments include a gate structure positioned on a silicon substrate and a gate oxide layer positioned on the silicon substrate, a polysilicon layer positioned on the gate oxide layer, a nitride layer, which includes nitride sidewalls, positioned on the polysilicon layer, and a tungsten plug that is positioned within a first trench portion between the nitride sidewalls and a second trench portion in the polysilicon layer.