Single Metal/Dual High-k Gate Stack with Low Vth and Precise Gate Profile Control for Highly Manufacturable Aggressively Scaled CMISFETs

We have proposed a single metal/dual high-k (SMDH), low-Vth gate stack for aggressively scaled CMISFETs. The Vth is controlled by MgO- and Al₂O₃-containing high-k for n and pMISFETs, respectively. The gate profile can be more easily controlled by taking advantage of a common W/TiN gate stack on both high-k´s. We have successfully obtained 0.21 and -0.33 V of V_th for a 1-mum long n and pMISFET by the proposed SMDH gate stacks. We also found that MgO suppresses PBTI and that it enhances electron mobility.