Direct tunneling leakage current and scalability of alternative gate dielectrics

We explore the scaling limits of alternative gate dielectrics based on their direct tunneling characteristics and gate leakage requirements for future complementary metal–oxide–semiconductor technology generations. Important material parameters such as the tunneling effective mass are extracted for several promising high-κ gate dielectrics. We also introduce a figure of merit for comparing the relative advantages of gate dielectric candidates. Using an accurate direct tunneling gate current model and specifications from the International Technology Roadmap for Semiconductors, we provide guidelines for the selection of gate dielectrics to satisfy the off-state leakage current requirements of future high-performance and low power technologies.