Self-aligned contacts for high k/metal gate process flow

Abstract

A semiconductor structure is provided that includes a semiconductor substrate having a plurality of gate stacks located on a surface of the semiconductor substrate. Each gate stack includes, from bottom to top, a high k gate dielectric layer, a work function metal layer and a conductive metal. A spacer is located on sidewalls of each gate stack and a self-aligned dielectric liner is present on an upper surface of each spacer. A bottom surface of each self-aligned dielectric liner is present on an upper surface of a semiconductor metal alloy. A contact metal is located between neighboring gate stacks and is separated from each gate stack by the self-aligned dielectric liner. The structure also includes another contact metal having a portion that is located on and in direct contact with an upper surface of the contact metal and another portion that is located on and in direct contact with the conductive metal of one of the gate stacks. Methods of forming the semiconductor structure using a replacement gate and a non-replacement gate scheme are also disclosed.