In this paper, we demonstrate the superior diffusion barrier properties of NO-nitrided SiO2 in suppressing boron penetration for p(+)-polysilicon gated MOS devices. Boron penetration effects have been studied in terms of flatband voltage shift, decrease in inversion capacitance (due to polysilicon depletion effect), impact on interface state density, and charge-to-breakdown, Results show that NO-nitrided SiO2, as compared to conventional thermal SiO2, exhibit much higher resistance to boron penetration, and therefore, are very attractive for surface channel PMOS technology.