Mass fabrication of resistive random access crossbar arrays by step and flash imprint lithography

摘要

Step and flash imprint lithography (SFIL) is a promising method recently used for nextgeneration lithographic technology because it is a high-speed process that can be carried out atroom temperature and low pressures. Improvements made to SFIL enable the replication ofcrossbar patterns with a high resolution and the development of suitable materials andtechniques to achieve high resolution capability. In this study, SFIL is used to fabricatehigh-density random access crossbar arrays based on a NiO resistive switching system. Thebottom and top electrodes are transferred onto silicon wafers perpendicular to each electrodeusing the inductively coupled plasma reactive ion etching (ICP-RIE) technique. Direct metaletching without a wet-based process minimizes damage to the electrode surface. The I–Vcurves of individual active cells (70 x 70 nm~2) for crossbar arrays reveal the unipolar resistiveswitching (RS) behaviour of the fabricated device. A high off/on resistance ratio (>104) andreproducible resistance switching characteristics for each active cell were found in differentfields and for different wafers. The experimental data indicate that high-density crossbar arrayscan be well replicated and that the electrical performance of these arrays is reliable.