A method of fabricating a tunneling photodiode is presented comprised of the following steps: forming a p-well in an n-type substrate, forming a thin insulating layer over the surface of the p-type material, and then forming a thin n-type layer over the insulating layer. Preferably, the n and p type semiconductor material could be silicon and the insulating layer could be between about 30 to 40 angstroms of gate quality silicon dioxide. In other embodiments of the invention the materials of either electrode are either n or p-type semiconductors or metals.