Oxide based two diodes–one resistor structure for bipolar RRAM crossbar array

• A new bipolar selector based on anti-parallel connected diodes is proposed.
• Anti-parallel connected Ag/TiOx/Ti diodes are fabricated as bipolar selector.
• The readout margin can be sufficiently improved with the bipolar selector.

A new bipolar selector to suppress the sneak current in crossbar array has been proposed using anti-parallel connected oxide diodes. The highly nonlinear I–V characteristics are realized by the anti-parallel connected Ag/TiOx/Ti oxide diodes. By connecting the selector and a bipolar Cu/HfO2/Pt RRAM in series, the sneak current can be effectively suppressed and the readout margin is sufficiently improved compared to that obtained without using the selector. The maximum array size of the crossbar array with the anti-parallel connected diodes selector can be increased to more than 1 Mb at a readout margin of 10%. These results indicate that the anti-parallel connected oxide diodes as a selector has great potential for high density bipolar RRAM crossbar array applications.

I–V characteristics of the anti-parallel connected Ag/TiOx/Ti diodes selector in series with the Cu/HfO2/Pt bipolar RRAM cell.Figure optionsDownload as PowerPoint slide