Actel Corporation, Inc.

Other

Shih-Oh Chen

Yeouchung Yen

James Bernard Kruger

Hung-Kwei Hu

Leuh Fang

Elaine K Poon

John L McCollum

Gregory William Bakker

Steve S Chiang

Abdul R Forouhi

Yen Yeouchung

Yen Yeuochung

The antifuse structure of the present invention includes a bottom planarized electrode, an ILD disposed over the bottom electrode, an antifuse cell opening in and through the ILD exposing the bottom electrode, a first barrier metal layer disposed in the antifuse cell opening to protect the antifuse material layer from diffusion from the bottom electrode and to form an effective bottom electrode of reduced area, hence reducing the capacitance of the device, an antifuse material layer disposed in the antifuse cell opening and over the first barrier metal layer, a second barrier metal layer disposed over the antifuse material layer, and a top electrode disposed over the second barrier metal layer.

Method of making a metal to metal antifuse

A method for fabricating the antifuse of the present invention comprises the steps of forming a lower antifuse electrode; forming a relatively thick interlayer dielectric layer over the surface of the lower antifuse electrode; forming a masking layer, preferably a photoresist, including an aperture therein having a first area over the interlayer dielectric layer; performing a first vertical etching step on the interlayer dielectric layer to a first selected depth; enlarging the aperture in the masking layer until it has a second area; performing a final vertical etching step on the interlayer dielectric layer to expose the upper surface of the lower electrode. Depending on the thickness of the interlayer dielectric, additional enlarging steps and vertical etching steps may be performed prior to the final vertical etching step which exposes the upper surface of the lower electrode. An aperture having a staircase profile is thereby formed, the aperture having a number of steps thus reducing and/or eliminating cusping and/or thinning at the corner and bottom of the antifuse cell opening allowing for the uniform deposit of dielectric and upper antifuse electrode materials.

Method for fabricating an electrically programmable antifuse

The antifuse structure of the present invention includes a bottom planarized electrode, an ILD disposed over the bottom electrode, an antifuse cell opening in and through the ILD exposing the bottom electrode, a first barrier metal layer disposed by means of collimated sputter deposition in the antifuse cell opening to form a layer of uniform thickness existing only within the antifuse cell opening in order to protect the antifuse material layer from diffusion from the bottom electrode and to form an effective bottom electrode of reduced area, hence reducing the capacitance of the device, an antifuse material layer disposed in the antifuse cell opening and over the first barrier metal layer, a second barrier metal layer disposed over the antifuse material layer and optionally formed by collimated sputter deposition, and a top electrode disposed over the second barrier metal layer.

Method of making metal to metal antifuse

An antifuse comprises a lower electrode and an upper electrode separated by an interlayer dielectric. An antifuse cell opening is disposed in the interlayer dielectric. The antifuse cell opening comprises at least two steps, wherein a first portion thereof has a first area and a second portion thereof disposed above the first portion has a second area larger than said first area. Additional portions may be provided above the second portion having successively larger areas if the thickness of the interlayer dielectric warrants their inclusion.

Electrically programmable antifuse having stair aperture

Metal to metal antifuse

An antifuse may be fabricated as a part of an integrated circuit in a layer located above and insulated from the semiconductor substrate. The antifuse includes a lower first electrode, a first dielectric layer disposed over the lower first electrode, a layer of amorphous silicon disposed above the first dielectric layer, a second dielectric layer disposed above the amorphous silicon layer, and an upper second electrode disposed above the second dielectric layer.

Electrically programmable antifuse incorporating dielectric and

A misalignment tolerant antifuse includes a lower electrode, bounded by a relatively thick first insulating layer, an upper electrode separated from the lower electrode by a second insulating layer having a thickness less than that of the first insulating layer, a pair of antifuse window regions in the second insulating layer, abutting the first insulating layer on opposite sides of the lower electrode, the insulating material in the window regions being thinner than the remainder of the second insulating layer, and an upper electrode disposed above the second insulating layer and lying over the pair of regions and at least a portion of the first insulating layer.

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Fremont, CA, United States of America

Shih-Oh Chen