Organic CuTCNQ nonvolatile memories for integration in the CMOS backend-of-line: preparation from gas/solid reaction and downscaling to an area of 0.25 μm2

CuTCNQ is an organic semiconductor charge transfer material that allows the realization of nonvolatile cross-bar memory arrays with conductivity switching. In this work, we present a simple preparation method of this organic memory material, compatible with industrial processing and downsizing of the memory cells. CuTCNQ was prepared on Cu by a solid-gas phase corrosion reaction between the metal and hot TCNQ gas at low pressure. Surface coverage increased with reaction time and temperature. Cu/CuTCNQ/Al cross-point cell arrays with memory areas of 0.01 mm² exhibited I-V curved with ON/OFF current ratios of about 10. Further downscaling of the memory elements was successful to an area of 0.25 μm² . Corresponding memories achieved ON/OFF current ratio of about 700. This is, to our knowledge, the first report on downscaling of organic memories to 0.25 μm².