Regular and Inverted Operating Regimes in TiN/a-Si/TiOx/TiN RRAM Devices

Non-localized and bipolar switching in vacancy modulated conductive oxide resistive switching devices (TiN/a-Si/TiOx/TiN) is attributed to defect profile modulation in the TiOx switching layer. We observe two modes of operation-stable regular and unstable inverted, corresponding to two sets of opposite switching polarities. This is explained using a kinetic defect distribution model. The position of the defect centroid and the distribution spread determine the switching regime. The unstable inverted regime exposes the reliability concern of erroneous programming which can be avoided by operating in the regular regime with reasonable programming margin.