US 5,852,323 A · Electrically programmable antifuse using metal penetration of a P-N junction

Abstract

An antifuse is described that can be formed without masks or mask steps beyond those required for a conventional CMOS process. The antifuse includes adjacent p-type and n-type diffusion regions that together form a P-N junction. The diffusion regions are tapered toward one another such that the P-N junction is located at a necked-down region of the antifuse. The diffusion regions are connected to respective terminals of a programming-voltage source via first and second metal electrical contacts, typically of aluminum metal. Each of the first and second electrical contacts includes a point directed toward the other of the first and second electrical contacts. The antifuse is programmed by providing a reverse-bias programming voltage across the electrical contacts. This programming voltage exceeds the breakdown voltage of the P-N junction so that current flows through the necked-down region of the antifuse between the points on the respective first and second electrical contacts. This current heats the region between the opposite points to create a hot filament between the first and second metal contacts. Metal from the metal contacts then diffuses along the filament to form a conductor between metal contacts.

Claims15

Dependent claims

An antifuse comprising:

a first diffusion region of a first conductivity type formed in a semiconductor layer, the first diffusion region having a first width in a dimension parallel to the semiconductor layer;
a second diffusion region of a second conductivity type formed in the semiconductor layer adjacent to the first diffusion region, the second diffusion region contacting the first diffusion region to form a P-N junction, the P-N junction having a second width in a dimension parallel to the semiconductor layer, wherein the second width is less than the first width;
a first metal electrical contact formed on the first diffusion region;
and
a second metal electrical contact formed on the second diffusion region.

2 more elements

Dependencies are inferred from the claim text.

Electrically programmable antifuse using metal penetration of a P-N junction

Life of this patent

Electrically programmable antifuse using metal penetration of a P-N junction

Life of this patent

Abstract

Claims15