Abstract: An antifuse comprises a lower electrode formed from a metal layer in a microcircuit. A interlayer dielectric layer is disposed over the lower electrode and has an aperture formed therein. A conductive plug, formed from a material such as tungsten, is formed in the aperture. The upper surface of the interlayer dielectric is etched back to create a raised portion of the plug. The upper edges of the plug are rounded. An antifuse layer, preferably comprising a silicon nitride, amorphous silicon, silicon nitride sandwich incorporating a thin silicon dioxide layer above or below the amorphous silicon layer or such a sandwich structure covered by a titanium nitride layer, is disposed above the plug. An upper electrode, preferably comprising a metal layer is disposed over the antifuse layer.

Abstract: An antifuse comprises a lower electrode formed from a metal layer in a microcircuit. A interlayer dielectric layer is disposed over the lower electrode and has an aperture formed therein. A conductive plug, formed from a material such as tungsten, is formed in the aperture. The upper surface of the interlayer dielectric is etched back to create a raised portion of the plug. The upper edges of the plug are rounded. An antifuse layer, preferably comprising a silicon nitride, amorphous silicon, silicon nitride sandwich incorporating a thin silicon dioxide layer above or below the amorphous silicon layer or such a sandwich structure covered by a titanium nitride layer, is disposed above the plug. An upper electrode, preferably comprising a metal layer is disposed over the antifuse layer.

Abstract: A metal-to-metal antifuse disposed between two aluminum metallization layers in a CMOS integrated circuit or similar structure includes an antifuse material layer having a substantially aluminum-free conductive link. The substantially aluminum-free link is formed by forming a first barrier metal layer out of TiN having a first thickness, a second barrier metal layer out of TiN having a second thickness which may be less than said first thickness, the first and second barrier metal layers separating the antifuse material layer from first and second electrodes. The antifuse is programmed by applying a voltage potential capable of programming the antifuse across the electrodes with the more positive side of the potential applied to the electrode adjacent the barrier metal layer having the least thickness.

Abstract: An antifuse comprises a lower electrode formed from a metal layer in a microcircuit. A interlayer dielectric layer is disposed over the lower electrode and has an aperture formed therein. A conductive plug, formed from a material such as tungsten, is formed in the aperture. The upper surface of the interlayer dielectric is etched back to create a raised portion of the plug. The upper edges of the plug are rounded. An antifuse layer, preferably comprising a silicon nitride, amorphous silicon, silicon nitride sandwich incorporating a thin silicon dioxide layer above or below the amorphous silicon layer or such a sandwich structure covered by a titanium nitride layer, is disposed above the plug. An upper electrode, preferably comprising a metal layer is disposed over the antifuse layer.

Abstract: An antifuse comprises a lower electrode formed from a metal layer in a microcircuit. A interlayer dielectric layer is disposed over the lower electrode and has an aperture formed therein. A conductive plug, formed from a material such as tungsten, is formed in the aperture. The upper surface of the interlayer dielectric is etched back to create a raised portion of the plug. The upper edges of the plug are rounded. An antifuse layer, preferably comprising a silicon nitride, amorphous silicon, silicon nitride sandwich incorporating a thin silicon dioxide layer above or below the amorphous silicon layer or such a sandwich structure covered by a titanium nitride layer, is disposed above the plug. An upper electrode, preferably comprising a metal layer is disposed over the antifuse layer.

Abstract: 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 metal electrode, a first antifuse dielectric layer, preferably silicon nitride, disposed on the lower first electrode and an antifuse layer, preferably amorphous silicon, disposed on the first dielectric layer. An inter-layer dielectric layer is disposed on the antifuse layer and includes an antifuse via formed completely therethrough. A second antifuse dielectric layer, preferably silicon nitride, is disposed over the amorphous silicon layer in the antifuse via, and an upper second metal electrode is disposed over the second dielectric layer in the antifuse via.

Abstract: A metal-to-metal antifuse disposed between two aluminum metallization layers in a CMOS integrated circuit or similar structure includes an antifuse material layer having an aluminum-free conductive link. The aluminum-free link is formed by forming a first barrier metal layer out of TiN having a first thickness, a second barrier metal layer out of TiN having a second thickness which may be less than said first thickness, the first and second barrier metal layers separating the antifuse material layer from first and second electrodes. The antifuse is programmed by applying a voltage potential capable of programming the antifuse across the electrodes with the more positive side of the potential applied to the electrode adjacent the barrier metal layer having the least thickness.

Abstract: An antifuse comprises first and second electrodes separated by an antifuse material having a thickness selected to impart a desired target programming voltage to the antifuse. The antifuse material comprises a solid material stable at temperatures below about 600.degree. C., having a defect density less than about 100 defects/cm.sup.2, a breakdown field less than about 10 megavolts/cm, a dielectric constant lower than about 4.0, a resistivity of greater than about 10.sup.4 ohm-cm. The antifuse material may comprise organic materials such as polyimides compatible with high-temperature processes including cured polyamic acids, pre-imidazed polymers, photo-sensitive polyimides, and other polimides such as pyralin, probimide, PIQ, etc. The antifuse materials of the present invention also include fluorinated polymers having very low dielectric constants, such as teflon, paralines, polyphenylquinoxaline, benzocyclobutene polymers, and perfluoropolymers.

Abstract: An additional column (or row) track is provided in an antifuse based interconnect array containing circuit structures identical to the circuit structures in the remaining columns of the array, except that antifuse vias are filled with contact or via plugs. These plug antifuse substitutes are addressable in the same manner and by the same circuitry as the antifuses on the integrated circuit. The programmed antifuse is addressed, a test voltage is placed on the V.sub.pp input pin on the integrated circuit, and the current drawn by the antifuse is measured. The plug antifuse substitute is addressed, the test voltage is placed on the V.sub.pp input pin on the integrated circuit, and the current drawn by the plug antifuse substitute is measured.

Abstract: 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 metal electrode, a first antifuse dielectric layer, preferably silicon nitride, disposed on the lower first electrode and an antifuse layer, preferably amorphous silicon, disposed on the first dielectric layer. An inter-layer dielectric layer is disposed on the antifuse layer and includes an antifuse via formed completely therethrough. A second antifuse dielectric layer, preferably silicon nitride, is disposed over the amorphous silicon layer in the antifuse via, and an upper second metal electrode is disposed over the second dielectric layer in the antifuse via.

Abstract: An additional column (or row) track is provided in an antifuse based interconnect array containing circuit structures identical to the circuit structures in the remaining columns of the array, except that antifuse vias are filled with contact or via plugs. These plug antifuse substitutes are addressable in the same manner and by the same circuitry as the antifuses on the integrated circuit. The programmed antifuse is addressed, a test voltage is placed on the V.sub.pp input pin on the integrated circuit, and the current drawn by the antifuse is measured. The plug antifuse substitute is addressed, the test voltage is placed on the V.sub.pp input pin on the integrated circuit, and the current drawn by the plug antifuse substitute is measured.

Abstract: Antifuses having minimum areas are formed by a process including the steps of forming doped regions in a semiconductor substrate, forming a dielectric layer over the surface of the substrate, performing masking and etching steps to form apertures in the dielectric layer over portions of the doped regions where antifuses are to be formed, depositing a second dielectric layer over the first dielectric layer and the apertures, the second dielectric layer having a faster etch rate than the first dielectric layer, etching the second dielectric layer to leave spacers at the edges of the apertures, forming the antifuse dielectric in the apertures, and forming upper antifuse electrodes over the antifuse dielectric.

Abstract: An additional column (or row) track is provided in an antifuse based interconnect array containing circuit structures identical to the circuit structures in the remaining columns of the array, except that antifuse vias are filled with contact or via plugs. These plug antifuse substitutes are addressable in the same manner and by the same circuitry as the antifuses on the integrated circuit. The programmed antifuse is addressed, a test voltage is placed on the V.sub.pp input pin on the integrated circuit, and the current drawn by the antifuse is measured. The plug antifuse substitute is addressed, the test voltage is placed on the V.sub.pp input pin on the integrated circuit, and the current drawn by the plug antifuse substitute is measured.

Abstract: A circuit for preventing false programming of unselected anti-fuses in an anti-fuse array includes a series impedance including a plurality of transistors which may be used for partial address selection connected between a source of programming voltage and a bit line.

Abstract: A semiconductor or substrate of a first conductivity type includes a well structure of a second conductivity type formed therein. A first low voltage MOS transistor includes spaced apart source and drain regions of the first conductivity type in the well. A first transistor gate lies above a channel region which is disposed between the source and drain regions of the first low voltage MOS transistor and is separated therefrom by a gate dielectric having a first thickness. A second high voltage transistor includes spaced apart source and drain regions of the first conductivity type in the well. A second transistor gate lies above a channel region which is disposed between the source and drain regions of the second high voltage transistor and is separated therefrom by a gate dielectric having a second thickness which is greater than the thickness of the gate dielectric of the first low voltage MOS transistor.

Abstract: An antifuse structure according to a first aspect of the present invention is programmed by snap-back breakdown and includes a semiconductor substrate of a first conductivity type, an insulating layer over the surface of the semiconductor substrate, a conductive gate disposed over the insulating layer, spacer elements disposed at the outer edges of the conductive gate, spaced-apart first and second lightly doped regions of a second conductivity type disposed in the semiconductor substrate, the first and second lightly doped regions aligned to the edges of the conductive gate, third and fourth more heavily doped regions of the second conductivity type disposed in the semiconductor substrate, the third and fourth regions contiguous with the first and second regions, respectively, and aligned to the edges of the spacer elements, and a conductive filament in the insulating layer connecting the conductive gate to one of the second and fourth doped regions.

Abstract: The present invention includes four approaches to reduce the unintended programming of antifuses while programming selected antifuses and to decrease the programming time. The first approach includes circuitry to maintain the voltage placed on unselected antifuses at a constant level by use of a voltage source. According to the second approach, a resistor is included in series with the voltage source. According to the third approach, a diode is included in series with the voltage source. According to the fourth approach, a MOS implementation of a diode is included in series with the voltage source.