Effect of NO₂ and NH₃ on the resistive switching behavior of W/Cu _x O/Cu devices

Abstract

Cu x O-based devices were fabricated and investigated for the effect of nitrogen dioxide (NO2) and ammonia (NH3) on resistive switching behavior. Bottom copper (Cu) electrodes, copper-rich copper oxide (Cu x O) switching layers, and top tungsten (W) electrodes were sputtered onto two separate substrates to achieve two sets of memristors. Groups of holes ranging in diameter from 300 nm to 2 µm were wet etched into the top memristor layer to expose the Cu x O surface. At room temperatures, one substrate was subjected to 20 ppm of NO2 gas then a second substrate was subjected to 100 ppm of NH3 to measure the effect on memristance. For the first substrate, low and high resistance states demonstrated decreased values while the overall hysteresis gap collapsed after 10 min of exposure to NO2. The second substrate also showed decreases in resistance states but with a widening of the hysteresis gap after exposure to NH3 for 20 min. Recovery of both devices were visible at 25 and 30 min, respectively.