Reliability issues for high-k gate dielectrics

High-k gate dielectric materials are likely to be implemented in Si CMOS processes in the near future. Reliability characteristics that closely match, or exceed, those of SiO/sub 2/ will be one of the primary goals of future development work. In this paper we review the status of reliability studies of high-k gate dielectrics. High-k materials show novel reliability phenomena related to the asymmetric gate band structure and the presence of fixed charge. The reliability of high-k structures is influenced both by the interfacial layer as well as the high-k layer. Attainment of reliability goals will require elimination of charging effects, which dominate transistor degradation.