Mitigation of Complementary Metal–Oxide–Semiconductor Variability with Metal Gate Metal–Oxide–Semiconductor Field-Effect Transistors

Variability due to Fermi level pinning at polycrystalline silicon gate grain boundary is examined as an additional source of intrinsic parameter fluctuation. Threshold voltage (Vt) variation with metal gate to avoid the variation is found to be mitigated with the measurement of n-channel metal–oxide–semiconductor field-effect transistors (nMOSFETs) with an identical process except gate stack. The statistical variation of intrinsic gate delay and static noise margin of the 6 transistors static random access memory (SRAM) cell is predicted for future technology nodes using Monte Carlo circuit simulation with a process/physics-based compact model. It is found that the variability can be suppressed by ~35% with adopting metal gate for 32 nm technology node.