US Patent 11018011 Methods of forming contact features in semiconductor devices

A method includes forming a first trench in an isolation region; forming a second trench in a device region, wherein the device region is disposed adjacent to the isolation region and each of the first and second trenches is disposed between two metal gate structures; forming a first dielectric layer in the first and the second trenches; forming a second dielectric layer over and different from the first dielectric layer; removing a portion of the second dielectric layer from the first and the second trenches, leaving behind a remaining portion of the second dielectric layer in the first trench; removing a portion of the first dielectric layer formed over a bottom surface of the second trench; subsequent to removing the portion of the first dielectric layer, removing the remaining portion of second dielectric layer from the first trench; and forming contact features in the first and the second trenches.