Plasma processed ultra-thin SiO2 interfaces far advanced silicon NMOS and PMOS devices:: applications to Si-oxide Si oxynitride, Si-oxide Si nitride and Si-oxide transition metal oxide stacked gate dielectrics

The substitution of alternative gate dielectrics for thermally-grown SiO2 and nitrided SiO2 in aggressively scaled devices requires a significant processing change in going from thermally-grown to deposited dielectrics. This requires separate and independent steps for (i) the formation of Si-dielectric interface and (ii) the deposition of the dielectric thin film, which can be (a) Si nitride, or a Si oxynitride alloy, or Cb) a high-k oxide. It is demonstrated that ultra-thin, nitrided Si-SiO2 interface layers prepared by 300 degreesC remote plasma processing can be effective in insulating device performance and reliability from deleterious effects associated direct deposition of alternative dielectric materials directly on to hydrogen-terminated Si surfaces. These interfaces perform equally well with Si nitride, Si oxynitride and high-k oxides, and contribute approximately 0.3-0.4 nm to the overall electrical oxide thickness (EOT), limiting aggressive scaling of EOT to approximately 0.6 nm. (C) 2000 Elsevier Science S.A. All rights reserved.