Patent ID: 8399918

Claim:
An electronic device comprising: a tunnel structure comprising: a substrate having a primary surface and an active region; a first electrode including a lightly doped region of the substrate, wherein the first electrode extends to the primary surface and has a first conductivity type; a second electrode disposed over the first electrode, wherein; the second electrode is an only electrode of the tunnel structure disposed over the substrate; and substantially all of the second electrode has the first conductivity type; a tunnel dielectric layer disposed between the first and second electrodes; a first intermediate doped region of the substrate, wherein the first intermediate doped region is at the primary surface, abuts the lightly doped region, has a second conductivity type opposite the first conductivity type, and has a dopant concentration that is greater than a dopant concentration of the lightly doped region; and a first heavily doped region of the substrate, wherein the first heavily doped region is at the primary surface, abuts the lightly doped region, has the first conductivity type and a dopant concentration that is higher than the dopant concentration of the first intermediate doped region, and from a top view, is spaced apart from the second electrode.