Method for forming resistance-switching memory cell with multiple electrodes using nano-particle hard mask

A method for fabricating a resistance-switching memory device, comprising:

• depositing nano-particles on a bottom electrode layer on a substrate;
• etching the bottom electrode layer using the nano-particles as a mask, the etching results in a plurality of raised structures in the bottom electrode layer;
• removing the nano-particles;
• depositing an insulating material, the insulating material fills voids between the plurality of raised structures, and covers tops of the plurality of raised structures;
• polishing to remove a portion of the insulating material which is above the tops of the plurality of raised structures;
• etching to remove a residual of the insulating material which is above the tops of the plurality of raised structures, thereby exposing the tops of the plurality of raised structures while leaving portions of the insulating material in the voids;
• depositing a resistance-switching layer, a top of each raised structure is in contact with a bottom of the resistance-switching layer;
• and
• etching the resistance-switching layer and the bottom electrode layer in two orthogonal directions to form a plurality of resistance-switching memory cells, each resistance-switching memory cell comprises one or more of the raised structures as a bottom electrode and a portion of the resistance-switching layer as a resistance-switching material.

A method for fabricating a resistance-switching memory device, comprising:

• depositing nano-particles on a bottom electrode layer on a substrate;
• etching the bottom electrode layer using the nano-particles as a mask, the etching results in a plurality of raised structures in the bottom electrode layer;
• removing the nano-particles;
• depositing a resistance-switching material, a top of each raised structure is in contact with the resistance-switching material;
• and
• forming separate resistance-switching memory cells, each resistance-switching memory cell comprises one or more of the raised structures as a bottom electrode, a portion of the resistance-switching material and a top electrode, wherein the nano-particles are coated in a ligand, and the method further comprises etching the ligands after the depositing the nano-particles and before the etching the bottom electrode layer.