Two-fold coordinated nitrogen atom: an electron trap in MOS devices with silicon oxynitride as the gate dielectric

Having conducted semiempirical quantum-chemical simulation (MINDO/3) of several clusters at different charge states, we identify that the two-fold coordinated nitrogen atom with an un-paired electron (=Si2N .) is the most responsible trap center for the observation of large electronic capturing in SiOxNy. Our calculations also show that electron localized in this defect will result in spin dissipation. Trap formation and removal mechanisms during nitridation and re-oxidation are also discussed in this work.