Method of forming a contact

A method includes forming a first gate structure in a dielectric layer over a substrate, wherein the first gate structure includes a first gate stack and spacers along sidewalls of the first gate stack; recessing the first gate stack to form a first trench defined by the spacers, wherein upper portions of the spacers are exposed within the first trench; forming a first capping layer in the first trench, wherein the first capping layer has a first portion disposed along sidewalls of the upper portions of the spacers and a second portion disposed over the recessed first gate stack; applying a first implantation to convert the second portion of the first capping layer into a second capping layer; selectively removing the first portion of the capping layer to expose the upper portions of the spacers; and selectively removing the upper portions of the spacers.