Time decay of stress induced leakage current in thin gate oxides by low-field electron injection

Abstract

In this work we have shown that stress induced leakage current (SILC) in thin oxides can be effectively reduced at room temperature by performing low field current injection. If no current is injected, SILC is not reduced over a period of several days. We attribute this decrease to the passivation of the oxide weak spots by electron trapping in those weak spots mediating SILC. By increasing the amount of injected charge, SILC continuously decreases and no saturation steady state level is reached. The optimal condition for SILC abatement has been determined by varying the current intensity. This poses some questions on the true meaning of DC SILC, on the corresponding methods of measurements, and on its impact on the device lifetime.