US Patent 11532517 Localized etch stop layer

In one embodiment, a method includes providing a substrate comprising a source/drain contact region and a dummy gate, forming a first etch stop layer aligned to the source/drain contact region, where the first etch stop layer does not cover the dummy gate. The method may include forming a second etch stop layer over the first etch stop layer, the second etch stop layer covering the first etch stop layer and the dummy gate. The method may include converting the dummy gate to a metal gate. The method may include removing the second etch stop layer using a plasma etching process. The method may include removing the first etch stop layer.