Methods of forming contact features in field-effect transistors

Abstract

A method includes providing a semiconductor structure having metal gate structures (MGs), gate spacers disposed on sidewalls of the MGs, and source/drain (S/D) features disposed adjacent to the gate spacers; forming a first dielectric layer over the MGs and forming S/D contacts (MDs) over the S/D features; forming a second dielectric layer over the first dielectric layer, where portions of the second dielectric layer contact the MDs and the second dielectric layer is different from the first dielectric layer in composition; removing the portions of the second dielectric layer that contact the MDs; forming a conductive layer over the MDs and over the first dielectric layer; and removing portions of the conductive layer to form conductive features over the MDs.