To Alter Conductivity Of Fuse Or Antifuse Element Patents (Class 438/467)
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Patent number: 5895262Abstract: An etch of a fuse opening in overlying layers above a laser-blowable semiconductor fuse having a silicon nitride cap and silicon nitride spacers begins with a silicon nitride that is enclosed in a polysilicon conductive layer on a semiconductor wafer. The etch is performed by etching first with an etch process that etches silicon nitride and later with an etch process that is selective to silicon nitride. The later etch process etches the silicon nitride of the cap and spacers little or not at all, allowing a wider variation in etch depths without destroying the fuse. Also, a patch may be provided in the overlying layers above the fuse, and an etch process employed at the level of the patch that is selective to a material of the patch, resulting in an etch stop effect at that level. The etch process is then changed to an etch process that is not selective to a material of the patch, resulting in decreased variation in etch depth over the surface of the wafer.Type: GrantFiled: January 31, 1996Date of Patent: April 20, 1999Assignee: Micron Technology, Inc.Inventors: David S. Becker, Kunal R. Parekh
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Patent number: 5888858Abstract: Concentration of metal element which promotes crystallization of silicon and which exists within a crystal silicon film obtained by utilizing the metal element is reduced. A first heat treatment for crystallization is implemented after introducing nickel to an amorphous silicon film. Then, after obtaining the crystal silicon film, another heat treatment is implemented within an oxidizing atmosphere at a temperature higher than that of the previous heat treatment. A thermal oxide film is formed in this step. At this time, gettering of the nickel element into the thermal oxide film takes place. Then, the thermal oxide film is removed. Thereby, a crystal silicon film having low concentration of the metal element and a high crystalinity can be obtained.Type: GrantFiled: January 16, 1997Date of Patent: March 30, 1999Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Satoshi Teramoto, Jun Koyama, Yasushi Ogata, Masahiko Hayakawa, Mitsuaki Osame
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Patent number: 5882997Abstract: A resistive load structure and method for making a resistive load structure for an integrated circuit includes the use of an amorphous silicon "antifuse" material. The resistive load structure can be used in an SRAM cell to provide a load to counteract charge leakage at the drains of two pull-down transistors and two pass transistors of the SRAM cell. The resistive load structure is advantageously formed by depositing an amorphous silicon pad over a conductive via, and the resistance of the resistive load structure is controlled by adjusting the thickness of the amorphous silicon pad and varying the diameter of the underlying conductive via.Type: GrantFiled: October 21, 1997Date of Patent: March 16, 1999Assignee: VLSI Technology, Inc.Inventors: Harlan Lee Sur, Jr., Subhas Bothra
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Patent number: 5880512Abstract: Antifuses and gate arrays with antifuses are disclosed that have high thermal stability, reduced size, reduced leakage current, reduced capacitance in the unprogrammed state, improved manufacturing yield, and more controllable electrical characteristics. Some antifuses include spacers in the antifuse via. In some antifuses, the programmable material is planar, and the top or the bottom electrode is formed in the antifuse via. In some gate arrays, the antifuses are formed above the dielectric separating two levels of routing channels rather than below that dielectric.Type: GrantFiled: December 18, 1996Date of Patent: March 9, 1999Assignee: QuickLogic CorporationInventors: Kathryn E. Gordon, Richard J. Wong
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Patent number: 5856213Abstract: An antifuse structure is formed between two metal contacts in which a thin oxide layer is formed on the first or bottom metal, a shallow via is provided oxide layer and a layer of amorphous silicon is deposited over the thin oxide and into the shallow via without leaving the usual furrows in the amorphous silicon and thereby eliminating the step coverage problems of cusps forming in the subsequently applied second or top metal.Type: GrantFiled: July 25, 1996Date of Patent: January 5, 1999Assignee: VLSI Technology, Inc.Inventors: Michela S. Love, Delbert H. Parks
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Patent number: 5851903Abstract: A method for decreasing the pitch of polysilicon fuses uses tungsten barriers formed adjacent to the fuse elements. The tungsten barriers are made compatible with the process to form a crack stop by stacking tugsten at the via level on top of the tungsten at the contact level in the crack stop. An interlevel dielectric is used as a cover for the fuse.Type: GrantFiled: February 21, 1997Date of Patent: December 22, 1998Assignee: International Business Machine CorporationInventor: Anthony K. Stamper
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Patent number: 5811870Abstract: According to the preferred embodiment, an antifuse structure and method for personalizing a semiconductor device is provided that overcomes the limitations of the prior art. The preferred embodiment antifuse comprises a two layer transformable insulator core between two electrodes. The transformable core is normally non-conductive but can be transformed into a conductive material by supplying a sufficient voltage across the electrodes. The two layer core preferably comprises an injector layer and a dielectric layer. The injector layer preferably comprises a two phase material such as silicon rich nitride or silicon rich oxide. Initially, the injector layer and dielectric layer are non-conductive. When a sufficient voltage is applied the core fuses together and becomes conductive.Type: GrantFiled: May 2, 1997Date of Patent: September 22, 1998Assignee: International Business Machines CorporationInventors: Arup Bhattacharyya, Robert M. Geffken, Chung H. Lam, Robert K. Leidy
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Patent number: 5811330Abstract: An overvoltage protection device, for inclusion within an integrated circuit, which comprises at least two conductive elements separated by a gas filled gap.Type: GrantFiled: July 29, 1997Date of Patent: September 22, 1998Assignee: SGS-Thomson Microelectronics S.A.Inventor: Alexander Kalnitsky
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Patent number: 5807786Abstract: A method for forming an antifuse interconnect structure, for a one-time fusible link, to be used with field-programmable gate arrays, has been developed. The process features the use of an amorphous silicon layer, used as the antifuse layer, with the amorphous silicon layer protected by a thin barrier layer, during the patterning procedure. The protected antifuse layer results in a reproducible thickness, and thus reproducible pulsing voltages, needed for rupturing of the antifuse layer. Planarization of an underlying metal plug, via an insulator refill procedure, offers a smooth surface for the overlying antifuse layer.Type: GrantFiled: July 30, 1997Date of Patent: September 15, 1998Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.Inventor: Tzong-Sheng Chang
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Patent number: 5793094Abstract: A method for substantially reducing variations in a programming voltage of an anti-fuse structure formed on an integrated circuit wafer. The anti-fuse structure has a metal-one layer, an anti-fuse layer disposed above the metal-one layer, a oxide layer disposed above the anti-fuse layer, and a via hole in the oxide layer through to the anti-fuse layer for receiving a deposition of a metal-two material. The method includes the step of rendering a selected anti-fuse area susceptible to fuse link formation by reducing a resistivity of the selected anti-fuse area to diffusion of atoms from one of the metal-one layer and the metal-two layer when a programming voltage is applied between the metal one layer and the metal two layer. The selected anti-fuse area is located in the anti-fuse layer and substantially adjacent to and outside of an anti-fuse area directly below the via hole. The method further includes the step of depositing the metal-two material into the via hole.Type: GrantFiled: December 28, 1995Date of Patent: August 11, 1998Assignee: VLSI Technology, Inc.Inventors: Ivan Sanchez, Yu-Pin Han, Ying-Tsong Loh, Walter D. Parmantie
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Patent number: 5786268Abstract: Antifuses and gate arrays with antifuses are disclosed that have high thermal stability, reduced size, reduced leakage current, reduced capacitance in the unprogrammed state, improved manufacturing yield, and more controllable electrical characteristics. Some antifuses include spacers in the antifuse via. In some antifuses, the programmable material is planar, and the top or the bottom electrode is formed in the antifuse via. In some gate arrays, the antifuses are formed above the dielectric separating two levels of routing channels rather than below that dielectric.Type: GrantFiled: August 1, 1997Date of Patent: July 28, 1998Assignee: QuickLogic CorporationInventors: Kathryn E. Gordon, Richard J. Wong
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Patent number: 5783467Abstract: An antifuse structure includes a first electrode, a layer of enhanced amorphous silicon over the first electrode, and a second electrode over the layer of enhanced amorphous silicon. The layer of enhanced amorphous silicon is formed by an ion-implantation of a neutral species and a dopant species into a deposited layer of amorphous silicon, such that the antifuse structure will have a stable conductive link in a programmed state and such that it will be less susceptible to off-state leakage in an unprogrammed state. A method for making an antifuse structure includes forming a lower electrode, depositing an amorphous silicon layer over the lower electrode, ion-implanting a neutral species and a dopant species into the amorphous silicon layer, and forming an upper electrode over the amorphous silicon layer.Type: GrantFiled: December 29, 1995Date of Patent: July 21, 1998Assignee: VLSI Technology, Inc.Inventors: Yu-Pin Han, Ying-Tsong Loh, Ivan Sanchez
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Patent number: 5780918Abstract: An input part of a semiconductor integrated circuit includes a fuse element formed from a metal wiring layer and connected between an input pad and a source line is formed from wiring material. The wiring material is aluminum, possibly doped with silicon. The fuse element is narrowed or thinned at a location remote from an internal circuit. The stability and certainty of the melting properties of the fuse element at the narrowed of thinned location is improved even when the device is sealed with resin, without interfering with the manufacturing process, and at the same time the desired fuse element properties are retained. Consequently, the operating characteristics of the internal circuit can be adjusted highly precisely and with certainty after the assembly of the integrated circuit into a package.Type: GrantFiled: August 12, 1996Date of Patent: July 14, 1998Assignee: Seiko Epson CorporationInventor: Kanji Aoki
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Patent number: 5763299Abstract: An antifuse includes an antifuse material disposed between a lower conductive electrode and an upper conductive electrode. The antifuse material includes a layer of amorphous silicon disposed between two layers of silicon nitride. A thin layer of silicon dioxide is disposed between the layer of amorphous silicon and one of the silicon nitride layers.Type: GrantFiled: March 12, 1996Date of Patent: June 9, 1998Assignee: Actel CorporationInventors: John L. McCollum, Frank W. Hawley
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Patent number: 5759876Abstract: An antifuse includes a metal cap layer located at the second barrier layer of the antifuse to improve the antifuse yield and long term reliability. An antifuse further includes one or more interfacial oxide film layers surrounding an antifuse dielectric layer to provide narrowing of the antifuse programming voltage distribution and to further improve the antifuse yield and long term reliability.Type: GrantFiled: November 1, 1995Date of Patent: June 2, 1998Assignee: United Technologies CorporationInventors: Scott G. Singlevich, Bradley S. Holway, Kurt D. Humphrey, Brian Scott Poarch, Michael R. Reeder, Neal J. Verzwyvelt
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Patent number: 5759877Abstract: A semiconductor structure comprising a polysilicon pad, a metal pad separated from the polysilicon pad by an insulator, and a metal via connecting the pads. A fuse is formed at the intersection of the polysilicon pad and via.Type: GrantFiled: April 14, 1997Date of Patent: June 2, 1998Assignees: AT&T Global Information Solutions Company, Hyundai Electronics America, Symbios, Inc.Inventors: Harold S. Crafts, William W. McKinley, Mark Q. Scaggs
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Patent number: 5753540Abstract: Disclosed is a method for programming an antifuse structure. The antifuse structure is programmed by applying an alternating current having alternating current pulses between a bottom and a top electrode to generate a conduction path through an antifuse material sandwiched between the electrodes. The conduction path is formed incrementally due to an electron flow produced as a result of each alternating current pulse thereby defining the conduction path at a substantially centered portion of the antifuse material.Type: GrantFiled: August 20, 1996Date of Patent: May 19, 1998Assignee: VLSI Technology, Inc.Inventors: Koucheng Wu, Ivan Sanchez, Yu-Pin Han, Ying-Tsong Loh
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Patent number: 5741731Abstract: A method of manufacturing a semiconductor device including the steps of: forming an insulating film on an electrical connection area; forming a contact hole in the insulating film; forming a crystalline semiconductor region in the contact hole; forming a wiring layer covering the contact hole; and selectively implanting ions over the wiring layer by using a resist mask to make the crystalline semiconductor region have a high resistance. A semiconductor device having customized wiring connections can be manufactured in a short term.Type: GrantFiled: December 11, 1995Date of Patent: April 21, 1998Assignee: Yamaha CorporationInventor: Tomohiro Yuuki
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Patent number: 5742555Abstract: An integrated circuit anti-fuse is described which is fabricated as a capacitor using a layer of oxide. The two plates of the anti-fuse are coupled to appropriate voltage levels to rupture the oxide and form a conductive short between the plates. One of the plates is formed as a diffused well which is coupled to an external voltage during programming. The well is biased to an internal voltage during normal operation of the circuit incorporating the anti-fuse.Type: GrantFiled: August 20, 1996Date of Patent: April 21, 1998Assignee: Micron Technology, Inc.Inventors: Kenneth W. Marr, Shubneesh Batra
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Patent number: 5736777Abstract: A method and apparatus for fast electronic self-destruction of a CMOS integrated circuit. The present invention electrically destroys devices containing semiconductor components, securing the components from inspection by detecting the initiation of an attempt to inspect the component and, responsive thereto, electrically destroying the component. In some embodiments of the present invention, a switcheable pad having a destruct state and an operating state is connected to a well or to the substrate of the semiconductor device. When in destruct state, the switcheable pad drives the voltage of the well or substrate to a voltage that induces latch-up of the semiconductor device, allowing very large currents to flow through active or passive elements fabricated on the surface of the semiconductor device.Type: GrantFiled: December 29, 1995Date of Patent: April 7, 1998Assignee: Intel CorporationInventors: David J. Shield, Derek L. Davis
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Patent number: 5726483Abstract: A method of jointly forming stacked capacitors and antifuses includes, a) providing a common layer of electrically conductive material to form both a capacitor storage node and an inner antifuse plate; b) providing a common layer of dielectric material over the capacitor storage node and the inner antifuse plate, the common layer of dielectric material comprising both an intervening capacitor dielectric element and an intervening antifuse dielectric element, the common layer of dielectric material having a first breakdown voltage per unit length value for a given current per unit area; c) providing a common layer of electrically conductive material over the common layer of dielectric material to form both a capacitor cell layer and an outer antifuse plate; d) providing a lateral edge of the outer antifuse plate and a lateral edge of the intervening antifuse dielectric element; and e) depositing an antifuse breakdown layer of dielectric material over the lateral edges of the outer antifuse plate and the intervType: GrantFiled: July 17, 1995Date of Patent: March 10, 1998Assignee: Micron Technology, Inc.Inventor: Charles H. Dennison
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Patent number: 5665627Abstract: A fuse for an integrated circuit is constituted by a shallow NP junction, covered with a metal contact, the semiconductor region being not excessively doped. For the blowing of the fuse, the junction is forward biased with a current sufficient to enable a diffusion of metal up to the junction. This short-circuits the junction. The detection is done also by the forward biasing of the junction, but with a low current or a low voltage. The detection can also be done with reverse biasing.Type: GrantFiled: June 6, 1995Date of Patent: September 9, 1997Assignee: SGS Thomson Microelectronics S.A.Inventors: Richard Pierre Fournel, Serge Fruhauf, Fran.cedilla.ois Tailliet
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Patent number: 5641703Abstract: Methods and systems are discussed for fabricating electrically programmable link structures by fabricating a first metal conductor of a refractory conductive material, composite, or an aluminum alloy which has been modified with a refractory material, then fabricating an insulating link material over the first conductor, and subsequently, depositing a second conductor over the link material. In use, an electrical path can be formed between the first and second conductors by applying a voltage between such conductors across at least one selected region of the insulator, such that the insulating link material is transformed in the region and rendered conductive to form an electrical signal path.Type: GrantFiled: April 28, 1995Date of Patent: June 24, 1997Assignee: Massachusetts Institute of TechnologyInventors: Simon S. Cohen, Jack I. Raffel, Peter W. Wyatt