Resistance switching of CuTCNQ nanowires developed for high-density memory devices

Copper-7,7',8,8'-tetracyanoquinodimethane (CuTCNQ) is an interesting material for memory applications since it reversibly switches from high to low resistance states under external voltage. In this paper, CuTCNQ material was prepared from the gas/solid reaction between metallic copper and hot gaseous TCNQ at low pressure to form CuTCNQ nanowires. Nanowires were first grown on Au stripes and aluminum top electrode deposition enabled formation of crossbar memory structures. Electrical testing including standard current-voltage and data retention measurements were performed on the Au/CuTCNQ/AI stacks. Besides, in order to apprehend the resistive switching mechanisms, Raman spectroscopy was carried out on packaged structures enabling measurements under electrical field. Finally, in the perspective of high-density memory devices, CuTCNQ nanowires were grown in via arrays and characterized by electron transmission microscopy.