Boron Diffusion in Nitrided-Oxide Gate Dielectrics Leading to High Suppression of Boron Penetration in P-MOSFETs

Nitrided-oxide gate dielectrics have been proposed to suppress boron penetration in deep submicron metal-oxide-semiconductor field effect transistors (MOSFETs). However, few quantitative reports have been released on how nitrided oxides enlarge the permissible thermal budget. We evaluated the diffusivities of a nitrided oxide formed by annealing SiO2 in NO gas and demonstrated that this film enables us to use BF2 + for scaled devices. We also proposed a model depicting boron penetration through the nitrided-oxide layer.