In this study, we fabricated and analyzed resistance switching characteristics for resistance random access memory (RRAM) in a Pt/In2O3/SiO2/TiN structure. By applying opposing electric fields to performa soft breakdown of the In2O3/SiO2 insulating bi-layer, different switching behaviors are exhibited. When positive forming voltage was applied to the TiN electrode to soft breakdown the device, the resistance switching behavior was dominated by the bipolar mode. However, the negative voltage forming process exhibited both unipolar switching characteristics in addition to a bipolar switch mode. In order to analyze the composition of the conduction path and resistance switching mechanism, resistance value trends versus temperature was extracted and showed that the conduction paths of bipolar and unipolar modes are dominated by oxygen vacancies and metallic filament, respectively. Hence, metallic filament was considered to be formed by the migration of indium ions because the unipolar characteristic was only present during negative bias forming condition. (c) 2012 Elsevier B.V. All rights reserved.