An extension of the Curie-von Schweidler law for the leakage current decay in MIS structures including progressive breakdown

The leakage current decay and progressive breakdown in Al/HfYO _x/GaAs and Al/Y₂O₃/GaAs structures during constant voltage stress are investigated. It is shown that the Curie-von Schweidler law in combination with series and parallel resistances can describe the observed current decrease in these structures accurately. The circuit model incorporates an additional parallel leakage current path associated with the local degradation of the oxide layer as well. Even though the evolution of the current is remarkably different in HfYO_x than in Y₂O ₃ because of the applied stress voltage range and current magnitudes, the proposed model is able to capture the main features exhibited by the current-time characteristic in both cases. Experimental data from other authors are analyzed within the same framework.