An SRAM semiconductor device includes: at least a first and a second field effect transistor formed on a same substrate, each of the transistors including a gate stack, each gate stack including a semiconductor layer disposed on a metal layer, the metal layer being disposed on a high-k dielectric layer located over a chemical region, wherein the metal layer of the first gate stack and the metal layer of the second gate stack have approximately a same work function, and wherein each channel region has approximately a same band gap.