Altera Corporation

Shuang Xie

Cheng-Hsiung Huang

Albert Ratnakumar

Yow-Juang Bill Liu

Shankar Sinha

Shih-Lin S Lee

A contact fuse is provided. The contact fuse includes a metal oxide semiconductor (MOS) transistor and a control circuit having outputs coupled to a plurality of terminals of the MOS transistor. The control circuit is operable to forward bias a body-source junction during a programming operation and operable to short the body-source junction during a sensing operation. A method of operating a contact fuse is also provided.

Contact fuse

An integrated circuit with electrically programmable fuse circuitry coupled to a programming transistor is provided. The programming transistor may be a metal-oxide-semiconductor transistor that is separated from other circuitry in an integrated circuit substrate with shallow trench isolation. The electrically programmable fuse circuitry may be formed in a second layer above the integrated circuit substrate using a conductive material which may be tungsten-based. This second layer may further include interconnect wires made from the same conductive material. The electrically programmable fuse may be coupled to the programming transistor through vias and routing paths in a fourth layer above the integrated circuit substrate. The routing paths in the fourth layer may be made from a conductive material which may be different than the fuse conductive material used to form the programmable fuse circuitry.

Low-voltage programmable electrical fuses

Nonvolatile memory element circuitry is provided that is based on metal-oxide-semiconductor transistor structures. A nonvolatile memory element may be based on a metal-oxide-semiconductor transistor structure that has a gate, a drain, a source, and a body. During programming operations, control circuitry floats the body while applying a positive voltage to the drain and a negative voltage to the source. This causes the drain and source, which serve as the collector and emitter in a parasitic bipolar transistor, to break down. The drain-to-source (collector-to-emitter) breakdown causes sufficient current to flow through the source to alter the source electrode and thereby increase the resistance of the source significantly. During sensing operations, control circuitry may apply a voltage across the drain and source while grounding the body to determine whether the memory element has been programmed.

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Cupertino, CA, United States of America

Shuang Xie