Passivation quality of silicon nitride (SiNx), aluminum oxide (AlOx) and a stack of AlOx/SiNx has been investigated in the presence and absence of a thin silicon oxide (SiOx) layer formed using ozonated deionized water. Lifetime measurements show ≈3ms effective carrier lifetime (τeff) for the stack of AlOx/SiNx in the presence of the oxide. Low saturation current density (Jo) and interfacial trap density (Dit) confirm and explain the high τeff for this sample. The stack of AlOx/SiNx can offer excellent surface passivation because of both field-effect passivation and chemical passivation. Note that the presence of oxide also shows a crucial impact in achieving a good passivation.
