US Patent 11532480 Methods of forming contact features in semiconductor devices

A semiconductor structure includes an isolation feature disposed over a semiconductor substrate, a semiconductor fin disposed over the semiconductor substrate and adjacent to the isolation feature, a source/drain (S/D) feature disposed over the semiconductor substrate and apart from the isolation feature, an interlayer dielectric (ILD) layer disposed over the isolation feature and the S/D feature, a first contact plug disposed in the ILD layer and over the isolation feature, a second contact plug disposed in the ILD layer and over the S/D feature, and a dielectric layer between surfaces of the first contact plug and the ILD layer and between a sidewall of the second contact plug and the ILD layer, where a bottom surface of the second contact plug is free of the dielectric layer.