Proposal of Single Metal/Dual High- $k$ Devices for Aggressively Scaled CMISFETs With Precise Gate Profile Control

We have proposed a single metal/dual high-k gate stack for aggressively scaled complementary metal-insulator-semiconductor field-effect transistors (MISFETs). The threshold voltage is controlled by the dual high-k dielectrics, such as MgO- and Al₂O₃-containing HfSiON for n- and p-type MISFETs, respectively. The gate profile is precisely controlled by taking advantage of a common gate electrode, which will suppress the variation in device performance. Based on this device concept, we have actually fabricated W/TiN/HfMgSiON n-type MISFETs and W/TiN/HfAlSiO p-type MISFETs and have successfully demonstrated a low threshold voltage operation for both of n- and p-type MISFETs.