Abstract: Embodiments of the present disclosure provide semiconductor device structures and methods of forming the same. The structure includes a source/drain region disposed over a substrate, a first interlayer dielectric layer surrounding a first portion of the source/drain region, a second interlayer dielectric layer distinct from the first interlayer dielectric layer surrounding a second portion of the source/drain region, a silicide layer disposed on the source/drain region, and a conductive contact disposed over the source/drain region. The conductive contact is disposed in the second interlayer dielectric layer.

Abstract: A semiconductor device includes a substrate, an interlayer dielectric layer, spacer structures, a gate insulating layer, a first work function metal layer and a metal gate. The interlayer dielectric layer is disposed above the substrate. The spacer structures are located in a trench of the interlayer dielectric. The gate insulating layer is disposed between inner sidewalls of the spacer structures. The gate insulating layer includes a first region doped with dipole dopant and second regions without the dipole dopant. The first region is connected with the second regions. The first region is horizontally located between the first work function metal layer and the spacer structures. The metal gate is disposed above the first work function metal layer. The metal gate is disposed between and in contact with the second regions.