Ultrathin nitrided gate dielectrics by plasma-assisted processing

Ultrathin (<3nm) gate dielectrics made by plasma nitridation of SiO2 films have been studied by a combination of physical (ellipsometry, Nuclear React ion Analysis, Medium Energy Ion Scattering, and Atomic Force Microscopy) an d electrical (C-V, I-V, and constant voltage stress) methods. The main obse rvation we report here is a reduction of leakage current in the nitrided ox ides at the expense of reduced (peak) mobility, flatband voltage shift (for high concentration of incorporated nitrogen) and lower breakdown strength.