Memory cells, and methods of forming such memory cells, are provided that include a carbon-based reversible resistivity switching material. In particular embodiments, methods in accordance with this invention form a memory cell by forming a layer of carbon material above a substrate, forming a barrier layer above the carbon layer, forming a hardmask layer above the barrier layer, forming a photoresist layer above the hardmask layer, patterning and developing the photoresist layer to form a photoresist region, patterning and etching the hardmask layer to form a hardmask region, and using an ashing process to remove the photoresist region while the barrier layer remains above the carbon layer. Other aspects are also provided.