Instability evolution within a-SiNx film assessed through MIS structure under bias and temperature stresses

The effects of positive and negative bias stresses on plasma enhanced chemi cal vapor deposited (PECVD) hydrogenated amorphous silicon nitride/crystal silicon (a-SiNx/c-Si) structures were investigated as a function of both ti me and temperature. It was shown that the bias stress induces forward (posi tive) or backward (negative) shift of the capacitance-voltage (C-V) charact eristic along the voltage axis according to the polarity of this applied st ress voltage. The injection of charge carriers from the semiconductor subst rate and their eventual dispersive hopping process, limiting the redistribu tion of charges throughout the insulator, seem consistent with the time evo lution of both do current and flat band voltage of the metal insulator semi conductor structure. (C) 2001 Elsevier Science B.V. All rights reserved.