Charge trapping and electrical degradation in atomic layer deposited Al2O3 films

In this work, we focus on the effects of electrical stress on the charge trapping behavior and electrical degradation of Al2O3 layers deposited by ALD. For this purpose, current-voltage (I-V) and capacitance-voltage (C-V) characteristics of Al/Al2O3/n(+)Si capacitors are analyzed before and after constant voltage stress (CVS). The results show that electron trapping and hard breakdown (HBD) phenomena are the main degradation mechanisms observed under positive bias stress (or substrate injection). While, the generation of positive charge and new defects as well as the occurrence of soft breakdown (SBD) and progressive breakdown (PBD) failure modes, are identified as the dominant contributions when a highly enough negative bias (or gate injection) stress is applied. (C) 2013 Elsevier B.V. All rights reserved.