Antifuse array and method of forming antifuse using anodic oxidation

A one-time programmable device, comprising:

• a nanowire made of a first conductive material;
• a gate made of a second conductive material;
• and
• a gate oxide surrounding the nanowire, at least a portion of the gate oxide extending between the nanowire and the gate, the gate oxide being anodically oxidized from the first conductive material, wherein the gate oxide works as an antifuse between the nanowire and the gate;
• wherein the gate oxide has a tapered recess, wherein a depth of the tapered recess measured in a first direction is greater at a center of the gate oxide than a depth of the tapered recess measured in the first direction at edges of the gate oxide, and wherein the gate is positioned on top of the tapered recess, the gate oxide extending between the gate and the nanowire in the first direction.

A semiconductor device, comprising:

• a substrate;
• a first protrusion on the substrate, the first protrusion having a tapered recess, the first protrusion having a first height at edges of the first protrusion, the first height being measured in a first direction perpendicular to a major surface of the substrate, the first protrusion having a second height at a center of the first protrusion, the second height being measured in the first direction, the second height being less than the first height;
• a first line in the first protrusion;
• and
• a second line on top of the tapered recess of the first protrusion, wherein the first protrusion comprises a first antifuse between the first and second lines.