Defect generation in non-nitrided and nitrided sputtered gate oxides under post-irradiation Fowler-Nordheim constant current stress

Abstract

Metal oxide semiconductor (MOS) capacitors were fabricated with nitrided and non-nitrided sputtered oxides. The MOS structures were exposed to 2 Mrad gamma-ray dose and stored in a dry ambient for one year. Post-irradiation stability of MOS capacitors was investigated by applying Fowler-Nordheim constant current stress and monitoring the positive charge, border traps and interface states generation. It was found that nitridation increased the resistance of sputtered oxides to various defects generation under irradiation, electrical and combined radiation-electrical stress. The improved stability is explained in part by compensation of oxygen vacancy defects and Pb centers by nitrogen. © 2012 Elsevier B.V. All rights reserved.