Cross-point array of polymer junctions with individually-programmed conductances that can be reset

A method of forming a memory device, the method comprising the steps of:

• forming bottom metal lines on a substrate;
• forming polymer junctions on the bottom metal lines, wherein the polymer junctions comprise an organic polymer doped with a spiropyran and an acid;
• and
• forming top metal lines on the polymer junctions, wherein the method further comprises the steps of:
• depositing a continuous film of the organic polymer doped with the spiropyran and the acid onto the substrate over the bottom metal lines;
• forming a mask on the film that covers first portions of the film and leaves other second portions of the film exposed;
• and
• de-doping the second portions of the film to remove the acid making the second portions of the film electrically insulating, wherein the first portions of the film are electrically conductive and correspond to the polymer junctions, and wherein the mask is aligned with the polymer junctions.

A method of operating a memory device, the method comprising the steps of:

• applying a voltage bias to the memory device to program the memory device, wherein the memory device comprises:
• bottom metal lines;
• top metal lines;
• polymer junctions in between the bottom metal lines and the top metal lines, wherein the polymer junctions comprise an organic polymer doped with a spiropyran and an acid, and wherein the voltage bias, applied to the memory device via the bottom metal lines, opens the spiropyran in the polymer junctions forming an electron trap which reduces a conductivity of the polymer junctions;
• reading a resistance value of the polymer junctions;
• and
• heating the polymer junctions to close the spiropyran to restore the conductivity of the polymer junctions.