Composite contact etch stop layer

A method of fabricating a device, comprising:

• forming a plurality of sacrificial gate structures over a semiconductor substrate, wherein the sacrificial gate structures each include a sacrificial gate and a sacrificial gate cap formed over a top surface of the sacrificial gate;
• forming a sidewall spacer layer over sidewalls of the sacrificial gate structures;
• forming a first etch stop layer over the sidewall spacer layer and over a top surface of the sacrificial gate caps;
• forming a hard mask over the first etch stop layer;
• etching the hard mask to expose the first etch stop layer over the top surface of the sacrificial gate caps and recess the hard mask between adjacent sacrificial gate structures;
• removing exposed portions of the first etch stop layer from over the top surface of the sacrificial gate caps and from over surfaces of the sidewall spacer layer laterally adjacent to the sacrificial gate caps;
• removing remaining portions of the hard mask from between the adjacent sacrificial gate structures;
• and
• forming a second etch stop layer over the first etch stop layer and directly over the sacrificial gate caps.