There has recently been increased interest in carbon-based resistive random-access (RRAM) memory. Carbon-based RRAM has the potential to scale to atomic dimensions, resulting in ultra-high-density and low-power memory. Here we report reversible unipolar resistance switching in hydrogenated amorphous carbon. The devices used in this study are fabricated using e-beam lithography with built-in series resistors. A thorough analysis of the electrical transport and the resistance switching mechanism is presented. © 2013 IEEE.