RECESSING RMG METAL GATE STACK FOR FORMING SELF-ALIGNED CONTACT

摘要

Embodiments of the present invention may include methods of incorporating an embedded etch barrier layer into the replacement metal gate layer of field effect transistors (FETs) having replacement metal gates, as well as the structure formed thereby. The embedded etch stop layer may be composed of embedded dopant atoms and may be formed using ion implantation. The embedded etch stop layer may make the removal of replacement metal gate layers easier and more controllable, providing horizontal surfaces and determined depths to serve as the base for gate cap formation. The gate cap may insulate the gate from adjacent self-aligned electrical contacts.

主权项

1. A structure comprising:
a gate dielectric layer on a substrate; a work-function metal layer on the gate dielectric layer, the work-function metal layer having an upper surface that is substantially flush with an upper surface of the gate dielectric layer; a gate electrode on the upper surface of the gate dielectric layer and the upper surface of the work-function metal layer; a gate cap above the gate electrode, the gate cap having an upper surface that is substantially flush with an upper surface of a spacer that is adjacent to the gate cap, the gate electrode, and the gate dielectric layer; and a first embedded etch stop layer embedded in the spacer, the first embedded etch stop comprising dopant atoms.