To Alter Conductivity Of Fuse Or Antifuse Element Patents (Class 438/467)
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Patent number: 6362514Abstract: There is described a semiconductor device having a copper fuse which prevents damage to a silicon substrate beneath the copper fuse, which would otherwise be caused by a laser beam radiated to blow the copper fuse. A light absorbing layer is formed on the copper fuse layer from material whose light absorption coefficient is greater than that of a copper wiring layer. Light absorbed by the light absorbing layer is transmitted, through heat conduction, to the copper wiring layer beneath the light absorbing layer and further to a barrier metal layer beneath the copper wiring layer. Even when the widely-used conventional laser beam of infrared wavelength is used, the copper fuse can be blown. Since a guard layer is formed below the fuse layer, there can be prevented damage to the silicon substrate, which would otherwise be caused by exposure to the laser beam of visible wavelength.Type: GrantFiled: July 13, 1999Date of Patent: March 26, 2002Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yasuhiro Ido, Takeshi Iwamoto, Rui Toyota
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Patent number: 6359325Abstract: A method of forming nano-scale features with conventional multilayer structures, and nano-scale features formed thereby. The method generally entails forming a multilayer structure that includes a polycrystalline layer and at least one constraining layer. The multilayer structure is patterned to form first and second structures, each of which includes the polycrystalline and constraining layers. At least the first structure is then locally heated, during which time the constraining layer restricts the thermal expansion of the polycrystalline layer of the first structure. As a result, stresses are induced in the polycrystalline layer of the first structure, causing substantially two-dimensional grain growth from the edge of the first structure. Sufficient grain growth occurs to produce a third structure which, based on the grain size of the polycrystalline layer, will be a nano-scale structure.Type: GrantFiled: March 14, 2000Date of Patent: March 19, 2002Assignee: International Business Machines CorporationInventors: Munir D. Naeem, Lawrence A. Clevenger
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Patent number: 6355967Abstract: In the fuse element structure of the semiconductor device, the first insulating film region is provided in a groove-like manner in the semiconductor substrate. Further, the fuse element is formed on the first insulating film region, and the second insulating film region is formed on the region on the fuse element and the first insulating film. The metal plug is connected to the fuse element, and the surface thereof is exposed to the surface of the second insulating film region. With this structure, the meltdown of the fuse by the laser blow is facilitated, and the area of the fuse is reduced. Thus, as the downsizing of the element is further advanced, it is possible to provide a fuse element structure capable of melting down a fuse without causing an affect on another fuse adjacent to the melted-down fuse with the scattering pieces thereof.Type: GrantFiled: April 20, 2000Date of Patent: March 12, 2002Assignee: Kabushiki Kaisha ToshibaInventor: Toshifumi Minami
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Publication number: 20020019115Abstract: A power rectifier having low on resistance, mass recovery times and low forward voltage drop. In a preferred embodiment, the present invention provides a power rectifier device employing a vertical device structure, i.e., with current flow between the major surfaces of the discrete device. The device employs a large number of parallel connected cells, each comprising a MOSFET structure with a gate to drain short via a common metallization. This provides a low Vf path through the channel regions of the MOSFET cells to the source region on the other side of the integrated circuit. A thin gate structure is formed annularly around the pedestal regions on the upper surface of the device and a precisely controlled body implant defines the channel region and allows controllable device characteristics, including gate threshold voltage and Vf. A parallel Schottky diode is also provided which increases the switching speed of the MOSFET cells.Type: ApplicationFiled: September 7, 2001Publication date: February 14, 2002Inventors: Vladimir Rodov, Wayne Y.W. Hsueh, Paul Chang, Michael Chern
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Patent number: 6344373Abstract: 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: June 29, 1998Date of Patent: February 5, 2002Assignee: International Business Machines CorporationInventors: Arup Bhattacharyya, Robert M. Geffken, Chung H. Lam, Robert K. Leidy
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Publication number: 20010050407Abstract: An information write-register embedded in an integrated circuit (IC) is made of a plurality of independently addressable gate-controlled components formed in an isolated p-well nested in a n-well. Gates over the p-well are positioned on an insulator geometrically formed so that it is susceptible locally to electrical conductivity upon applying an overstress voltage pulse, whereby binary information can be permanently encoded into the write-register. The overstress voltage pulse is applied between the gate and the p-well and is created when a write-enable pulse of predetermined polarity and duration is superposed by a p-well pulse of opposite polarity and shorter duration.Type: ApplicationFiled: June 2, 2001Publication date: December 13, 2001Inventors: Tito Gelsomini, Kemal Tamer San
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Publication number: 20010046726Abstract: Fuses for integrated circuits and semiconductor devices, methods for making the same, methods of using the same, and semiconductor devices containing the same. The semiconductor fuse contains two conductive layers—an overlying and underlying layer—on an insulating substrate. The underlying layer comprises titanium nitride and the overlying layer comprises tungsten silicide. The semiconductor fuse may be fabricated during manufacture of a local interconnect structure containing the same materials. The fuse, which may be used to program redundant circuitry, is blown by electrical current rather than laser beams, thus allowing the fuse width to be smaller than prior art fuses blown by laser beams. The fuse may also be blown by less electrical current than the current required to blow conventional polysilicon fuses having similar dimensions.Type: ApplicationFiled: July 9, 2001Publication date: November 29, 2001Inventors: Zhongze Wang, Michael P. Violette, Jigish Trivedi
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Patent number: 6323111Abstract: A fuse for use in an integrated circuit includes a dielectric layer into which a trench or void is etched defined by a top opening and a bottom floor. The trench includes at least one undercut which forms an overhang in the dielectric layer partially shielding the bottom floor. A second or barrier layer deposited onto the dielectric layer is interrupted or non-continuous at the undercut. A third, or electrically conductive layer, is electrically continuous over the fuse. A weak spot in the third layer exists in the lack of structural support by the second layer at the interruption. A further weak spot in the third layer exists in the electrical isolation of the conductor layer, i.e. no leakage current through the barrier layer, at the interruption.Type: GrantFiled: October 28, 1999Date of Patent: November 27, 2001Assignee: Agere Systems Guardian CorpInventors: Frank Y. Hui, Edward B. Harris
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Patent number: 6316346Abstract: The present application discloses a method of forming and operating a metal-to-metal antifuse with an amorphous carbon dielectric which provides a very high resistance off state and can be programmed at voltages compatible with deep submicron devices. Furthermore, the programmed filament achieves low resistance with low programming current while maintaining a high level of stability.Type: GrantFiled: September 5, 2000Date of Patent: November 13, 2001Inventor: Shubhra Gangopadhyay
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Patent number: 6300170Abstract: Integrated circuitry fuse forming methods, integrated circuity programming methods, and related integrated circuitry are described. In one implementation, a first layer comprising a first conductive material is formed over a substrate. A second layer comprising a second conductive material different from the first conductive material is formed over the first layer and in conductive connection therewith. A fuse area is formed by removing at least a portion of one of the first and second layers. In a preferred aspect, an assembly of layers comprising one layer disposed intermediate two conductive layers is provided. At least a portion of the one layer is removed from between the two layers to provide a void therebetween. In another aspect, programming circuitry is provided over a substrate upon which the assembly of layers is provided.Type: GrantFiled: September 10, 1999Date of Patent: October 9, 2001Assignee: Micron Technology, Inc.Inventor: H. Montgomery Manning
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Publication number: 20010020728Abstract: An integrated circuit has primary devices and redundant devices being selective substituted for the primary devices through at least one fuse. The fuse includes a first layer having at least one fuse link region, a second layer over the first layer and cavities in the second layer above the fuse link region.Type: ApplicationFiled: May 21, 2001Publication date: September 13, 2001Inventors: Axel C. Brintzinger, Edward W. Kiewra, Chandrasekhar Narayan, Carl J. Radens
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Patent number: 6277724Abstract: An array of sidewall-contacted antifuses is formed by a method that reduces the sensitivity of the array to masking alignment errors. The method forms a plurality of spaced-apart bit lines in a semiconductor material. Rows and columns of insulated contacts are formed on the semiconductor material such that each bit line is contacted a plurality of times by an insulated contact. In each row of contacts, each contact has an exposed sidewall. A plurality of word lines are then formed over the contacts such that a word line is formed over each exposed sidewall in a row of exposed sidewalls. The word lines include a dielectric layer and an overlying layer of conductive material.Type: GrantFiled: January 19, 1999Date of Patent: August 21, 2001Assignee: National Semiconductor CorporationInventors: Albert Bergemont, Alexander Kalnitsky
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Patent number: 6271574Abstract: An integrated circuit fuse includes a substantially bar-shaped central region and zones having electrical contacts. The central region includes a thinned zone forming a weak point facilitating fusing of the fuse by increasing the local current density as compared to standard fusing conditions. The thinned zone is preferably obtained by proximity optical effect between the fuse and adjacent dummy elements.Type: GrantFiled: May 12, 1999Date of Patent: August 7, 2001Assignee: STMicroelectronics S.A.Inventors: Philippe Delpech, Nathalie Revil
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Patent number: 6268638Abstract: An integrated circuit has primary devices and redundant devices being selective substituted for the primary devices through at least one fuse. The fuse includes a first layer having at least one fuse link region, a second layer over the first layer and cavities in the second layer above the fuse link region.Type: GrantFiled: February 26, 1999Date of Patent: July 31, 2001Assignee: International Business Machines CorporationInventors: Axel C. Brintzinger, Edward W. Kiewra, Chandrasekhar Narayan, Carl J. Radens
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Patent number: 6261937Abstract: A method for forming a semiconductor integrated circuit having a fuse and an active device. A dielectric layer is formed over the fuse and over a contract region of the active device. Via holes are formed through selected regions of the dielectric layer exposing underlying portions of the fuse and underlying portions of a contact region of the active device. An electrically conductive material is deposited over the dielectric layer and through the via holes onto exposed portions of the fuse and the contact region. Portions of the electrically conductive material deposited onto the fuse are selectively removed while leaving portions of the electrically conductive material deposited onto the contact region of the active device. A fill material is disposed in the one of the fuse, a bottom portion of such filling material being spaced from the fuse.Type: GrantFiled: June 24, 1998Date of Patent: July 17, 2001Assignee: Siemens AktiengesellschaftInventors: Dirk Többen, Stefan J. Weber, Axel Brintzinger
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Patent number: 6258700Abstract: A fusible link device disposed on a semiconductor substrate for providing discretionary electrical connections. The fusible link device of the invention includes a silicide layer and a polysilicon layer formed on the silicide layer and has a first un-programmed resistance. The silicide layer agglomerates to form an electrical discontinuity in response to a predetermined programming potential being applied across the suicide layer, such that the resistance of the fusible link device can be selectively increased to a second programmed resistance.Type: GrantFiled: May 18, 1999Date of Patent: July 10, 2001Assignee: Intel CorporationInventors: Mark T. Bohr, Mohsen Alavi
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Patent number: 6255144Abstract: Disclosed is a repairing fuse for semiconductor devices and fabrication therefor. The repairing fuse has a first conducting film and a plurality of second conducting films wherein the first conducting film and the second conducting films are initially disconnected and mutually connected upon illumination of a laser beam so as to repair the semiconductor devices. In a contact hole which has a lower part narrower than its upper part, the first conducting film is formed having a connection to a bottom wire layer atop a semiconductor substrate. The contact hole is formed in an interlayer insulating film deposited on the wire layer. The second conducting films are disconnected with each other, each having an end point at a predetermined part on the slant wall the upper part of the contact hole. This novel fuse concept eliminates conventional problems, bringing a significant improvement into the simplification and yield of a repairing process.Type: GrantFiled: June 8, 1999Date of Patent: July 3, 2001Assignee: Hyundai Electronics Industries, Co., Ltd.Inventors: Bae Keun Jeon, Myeung Sik Chang, Choon Sik Oh, Sung Wook Park
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Publication number: 20010005604Abstract: A fuse area structure in a semiconductor device and a method of forming the same are provided. The fuse area structure includes a protection film formed of a passivation film for preventing moisture from seeping into the sidewall of an exposed fuse opening. In order to form the protection film, an etching stop film is formed on a fuse line, and the fuse opening is formed at the same time using the etching stop film when a contact hole required for the semiconductor device is formed. A conductive material layer for forming an upper interconnection layer is formed on the entire surface of a resultant structure on which the contact hole and the fuse opening are formed. The conductive material layer formed on the fuse opening is removed. The exposed etching stop film is removed. Finally, the fuse area is completed by forming a passivation film on the entire surface of the resultant structure and removing the passivation film formed on the bottom of the fuse opening into which laser is to be irradiated.Type: ApplicationFiled: December 18, 2000Publication date: June 28, 2001Applicant: Samsung Electronics Co., Ltd.Inventors: Chi-hoon Lee, Young-hoon Park, Hyo-dong Ban, Sung-hoon Kho
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Patent number: 6252292Abstract: A vertically arranged fuse structure for a semiconductor device. A fuse stud is vertically arranged with respect to a major plane of the semiconductor device and adjacent and electrically connected to overlying electrically conducting material and underlying electrically conducting material. A fuse void is present in the vertically arranged fuse stud. In an unblown state, the fuse provides electrical connection between the overlying electrically conducting material and the underlying electrically conducting material. The electrical connection being breakable by passing electrical energy of a predetermined level through the fuse.Type: GrantFiled: June 9, 1999Date of Patent: June 26, 2001Assignee: International Business Machines CorporationInventors: Axel C. Brintzinger, Roy Iggulden, Stefan J. Weber, Peter Weigand
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Patent number: 6242335Abstract: An improved anti-fuse structure is formed on a silicon substrate of a first conductivity type. The anti-fuse has a first conductive layer formed on a surface of the substrate, a dielectric layer formed on the first conductive layer, and a second conductive layer formed on the dielectric layer. The second conductive layer has a portion extending beyond the dielectric layer above the surface of the substrate. A third conductive layer is contacted to this portion of the second dielectric layer. The anti-fuse further includes a well region having a graded doping profile formed in the silicon substrate under the portion of the second conductive layer to which the third conductive layer is contacted. The well region has a second conductivity type that is opposite the first conductivity type.Type: GrantFiled: September 2, 1999Date of Patent: June 5, 2001Assignee: Micron Technology, Inc.Inventors: Joseph C. Sher, Robert M. Gravelle
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Publication number: 20010002322Abstract: A metal silicide fuse for a semiconductor device. The fuse includes a conductive region positioned adjacent a common well of a first conductivity type, a terminal region positioned adjacent a well of a second conductivity type, and a narrowed region located between the terminal region and the conductive region and positioned adjacent a boundary between the two wells. Upon applying at least a programming current to the fuse, the fuse “blows” at the narrowed region. The diode or diodes between wells of different conductivity types wells and the Schottky diode or diodes between the remaining portions of the fuse and wells adjacent thereto control the flow of current through the remainder of the fuse and through the associated wells of the semiconductor device. When the fuse has been “blown”, the diodes and Schottky diodes prevent current of a normal operating voltage from flowing through the wells of the semiconductor device.Type: ApplicationFiled: January 12, 2001Publication date: May 31, 2001Inventors: Kenneth W. Marr, Michael P. Violette
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Patent number: 6235557Abstract: A programmable fuse implements redundancy in semiconductor devices and enables the repair of defective elements. In an example embodiment, a fuse is built in the second-to-the-last metal interconnect layer used in the circuit. An opening to expose the fuse is incorporated into an existing mask of the last metal interconnect layer, typically the pad mask. The passivation layer on top of the bond pads is opened to expose the bonding pads. At the same time, a residual oxide window is defined over the fuse. The residual oxide covering the fuse provides for a reliable and reproducible fuse.Type: GrantFiled: April 28, 1999Date of Patent: May 22, 2001Assignee: Philips Semiconductors, Inc.Inventor: Martin Manley
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Publication number: 20010001214Abstract: Conductive links are provided between conductive materials, e.g., metals, separated by a non-conductive material, e.g., a silicon based glass material. In a preferred embodiment a single pulse of laser energy is applied to at least one of the conductive materials to produce mechanical strain therein which strain initiates a fracturing of the non-conductive material so as to provide at least one fissure therein extending between the conductive materials. The laser energy pulse further causes at least one of the conductive materials to flow in such fissure to provide a conductive link between the conductive materials. Preferably, the non-conductive material is formed in layers such that an interface between the layers controls the fissures.Type: ApplicationFiled: December 8, 2000Publication date: May 17, 2001Inventor: Joseph B. Bernstein
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Publication number: 20010000758Abstract: A method of programming a semiconductor memory includes forming a multiplicity of fuse links in at least two mutually parallel planes in a semiconductor body, and separating the fuse links from one another with an electrical insulator. It also includes irradiating a selected fuse link with at least two laser beams and melting the selected fuse link by crossing the laser beams at the selected fuse link.Type: ApplicationFiled: December 4, 2000Publication date: May 3, 2001Applicant: Infineon Technologies AGInventors: Holger Gobel, Gunnar Krause
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Patent number: 6218279Abstract: A fuse for semiconductor devices in accordance with the present invention includes a substrate having a conductive path disposed on a surface thereof, a dielectric layer disposed on the substrate and a vertical fuse disposed perpendicularly to the surface through the dielectric layer and connecting to the conductive path, the vertical fuse forming a cavity having a liner material disposed along vertical surfaces of the cavity, the vertical surfaces being melted to blow the fuse. Methods for fabrication of the vertical fuse are also included.Type: GrantFiled: February 24, 2000Date of Patent: April 17, 2001Assignees: Infineon Technologies North America Corp., International Business Machines CorporationInventors: Stefan J. Weber, Axel Christoph Brintzinger, Roy Iggulden, Mark Hoinkis, Chandrasekhar Narayan, Robert Van den Berg
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Patent number: 6214630Abstract: A wafer level IC structure and a method of manufacturing this wafer level IC structure are proposed, which can help increase the yield of the IC manufacture. The wafer level IC structure is constructed on a semiconductor wafer which is defined into a plurality of discrete IC blocks on the wafer, each IC block being used to form a plurality of IC components such as memory cells. A multi-layer interconnect structure is formed to electrically interconnect these IC components in each of the IC blocks. A first testing and repair process is then perform to disconnect any inoperative IC components from active use. This completes the fabrication stage of the manufacture process. In the subsequent packaging stage, a redistribution line structure is formed to interconnect the discrete IC blocks into an integral functional unit. A second testing and repair process is then perform to disconnect any inoperative IC blocks from active use.Type: GrantFiled: December 22, 1999Date of Patent: April 10, 2001Assignee: United Microelectronics Corp.Inventors: Min-Chih Hsuan, Taisheng Feng, Charlie Han
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Patent number: 6190986Abstract: A method for forming an interconnect wiring structure, such as a fuse structure, comprises forming an opening in an insulating layer using a phase shift mask (the opening having vertical sidewalls sloped sidewalls and horizontal surfaces), depositing a conductive material in the opening and removing the conductive material from the sloped sidewalls and horizontal surfaces, wherein the conductive material remains on the vertical sidewalls as fuse links.Type: GrantFiled: January 4, 1999Date of Patent: February 20, 2001Assignee: International Business Machines CorporationInventors: Kenneth C. Arndt, Louis L. Hsu, Jack A. Mandelman, K. Paul Muller
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Patent number: 6168969Abstract: A die incorporating vertical conductors, or vias, extending from active and passive devices on the active die side to the back side thereof. The vias are preferably formed in the die material matrix by introduction of a conductive material as known in the art. Such die may be employed in singulated fashion on a carrier substrate as an alternative to so-called “flip chip” die, or in vertically-stacked fashion to form a sealed multi-chip module the same size as the die from which it is formed. Certain vias of the various dice in the stack may be vertically aligned or superimposed to provide common access from each die level to a terminal such as a bond pad or C4 or other connection on the back side of the lowermost die contacting the carrier, while other stacked vias are employed for individual access from each die level to the carrier through the back side of the lowermost die.Type: GrantFiled: August 12, 1997Date of Patent: January 2, 2001Assignee: Micron Technology, Inc.Inventor: Warren M. Farnworth
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Patent number: 6159836Abstract: A programmable semiconductor contact structure and method are provided. A semiconductor substrate has a first patterned conductive layer for forming an interconnect. A first insulating layer overlies the first patterned conductive layer. An opening is formed through the insulating layer to the first patterned conductive layer to form the contact via. A buffer layer overlies portions of the first insulating layer and covers the opening. A second conductive layer overlies the buffer layer. A third conductive layer then overlies the integrated circuit. The buffer layer is a material, such as amorphous silicon, which functions as an anti-fuse and can be programmed by application of a relatively high programming voltage.Type: GrantFiled: May 8, 1995Date of Patent: December 12, 2000Assignee: STMicroelectronics, Inc.Inventor: Che-Chia Wei
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Patent number: 6156588Abstract: The invention relates generally to integrated circuits and, in particular, to methods of forming anti-fuse structures during integrated circuit manufacture. In an exemplary embodiment of the invention, a conductive base layer is formed over a semiconductor substrate. An insulating layer is formed on the conductive base layer and is patterned to expose a portion of the conductive base layer. An anti-fuse layer is formed on the insulating layer and the exposed portion of the conductive base layer. A conductive protection layer is formed on the anti-fuse layer. An anti-fuse island is formed by sequentially removing a portion of the conductive protection layer, and underlying portions of the anti-fuse layer and the insulating layer. The conductive base layer is patterned after forming the anti-fuse island. The invention provides a simplified method for the formation of anti-fuse structures which is compatible with submicron device geometries.Type: GrantFiled: June 23, 1998Date of Patent: December 5, 2000Assignee: VLSI Technology, Inc.Inventors: Ivan Sanchez, Miguel A. Delgado
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Patent number: 6153450Abstract: A semiconductor device according to the present invention is formed on a semiconductor chip and has a common module and a plurality of selectable modules. Each selectable module on the semiconductor chip performs a defined function and has a separate input power terminal. The device also has a voltage pad for connecting to a first voltage source having a first voltage level, so that the voltage pad supplies power to the input power terminal of each selectable module. The output of each selectable module may be connected to one common output pad, or alternatively, may be connected to a dedicated output pad. Also connected to each selectable module is a die/sort pad used for disconnecting a corresponding selectable module from the first voltage source. In the wiring between the first voltage source and the selectable modules, there is provided a plurality of fuses, each fuse having first and second terminals.Type: GrantFiled: January 25, 1999Date of Patent: November 28, 2000Assignee: Kabushiki Kaisha ToshibaInventor: Kimihiko Deguchi
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Patent number: 6146925Abstract: 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: January 28, 1998Date of Patent: November 14, 2000Assignee: Micron Technology, Inc.Inventor: Charles H. Dennison
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Patent number: 6140212Abstract: A semiconductor device (10) is formed to have multiple external connection pads (17, 18) for an active element (12). The multiple external connection pads (17, 18) are electrically connected together with a electrical link (19). After testing, the electrical link (19) is removed to disconnect the multiple external connection pads (17, 18) from each other.Type: GrantFiled: June 1, 1998Date of Patent: October 31, 2000Assignee: Motorola, Inc.Inventor: Henry L. Pfizenmayer
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Patent number: 6124193Abstract: 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.Type: GrantFiled: April 17, 1998Date of Patent: September 26, 2000Assignee: Actel CorporationInventors: Frank W. Hawley, John L. McCollum, Ying Go, Abdelshafy Eltoukhy
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Patent number: 6107165Abstract: A metal-to-metal conductive plug-type antifuise has a conductive plug disposed in an opening in an insulating layer. A programmable material feature (for example, amorphous silicon) overlies the conductive plug. A conductor involving a metal (for example, aluminum or copper) that migrates in the programmable material overlies the programmable material. To prevent migration of metal from the conductor into the programmable material when the antifuse is not programmed, the conductor has a layer of barrier metal between the metal that migrates and the programmable material. In some embodiments, there are two layers of barrier metal. An airbreak after formation of the first barrier metal layer improves the ability of the barrier metal to prevent diffusion between the programmable material and the overlying conductor.Type: GrantFiled: August 13, 1998Date of Patent: August 22, 2000Assignee: QuickLogic CorporationInventors: Rajiv Jain, Andre Stolmeijer, Mehul D. Shroff
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Patent number: 6097077Abstract: 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: May 8, 1998Date of Patent: August 1, 2000Assignee: Quicklogic CorporationInventors: Kathryn E. Gordon, Richard J. Wong
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Patent number: 6033938Abstract: Treatment of the positive electrode interface of an antifuse provides significantly improved on-state reliability. Treatments include, but are not limited to, a plasma etch using carbon tetrafluoride (CF.sub.4), a sputter clean using Argon, and wet chemical treatments using dimethyl formamide (and water) or a resist developer.Type: GrantFiled: November 15, 1996Date of Patent: March 7, 2000Assignee: Xilinx, Inc.Inventors: Martin L. Voogel, Yakov Karpovich, Michael J. Hart
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Patent number: 6028756Abstract: An integrated circuit includes topological features for weakening or otherwise modifying a blowable fuse in order to decrease the current needed to blow the fuse. This allows a decrease in the size of the circuit components which are needed to supply the current for blowing the fuse, in turn allowing compaction of the layout of the circuitry needed to blow the fuse. To this end, topological features are used to deform the shape of or otherwise modify the fuse, in turn increasing the resistance of the fuse or introducing flaws that allow the fuse to blow at a lower current.Type: GrantFiled: March 11, 1998Date of Patent: February 22, 2000Assignee: Lucent Technologies, Inc.Inventors: Ronald Lamar Freyman, Bruce Walter McNeill, Malcolm Harold Smith, Gary H. Weiss, Charles Raymond Miller
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Patent number: 6025214Abstract: An improved laser fusible link structure for semiconductor devices (200) and method of manufacturing thereof (10) is disclosed. A first conductive layer is patterned to create a laser fuse (202) and then covered with a first dielectric layer (212). An etch mask layer, in the preferred embodiment a second layer of polysilicon, is deposited and patterned to form a fuse etch mask (214) directly over the laser fuse (202). The fuse etch mask (214) has a width that is smaller than a minimum laser spot size, but large enough to protect the laser fuse (202) from fuse window over-etch, taking into account any potential misalignment between the laser fuse (202) and the fuse etch mask (214).Type: GrantFiled: October 22, 1997Date of Patent: February 15, 2000Assignee: Alliance Semiconductor CorporationInventors: Chitranjan N. Reddy, Ajit K. Medhekar
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Patent number: 5994170Abstract: The present invention is a method and apparatus for programming a stack of segments wherein each segment includes a plurality of die which are interconnected through metal interconnects patterned on the surface of each segment. Once the segments are arranged into a stack, the stack is connected to external circuits and each segment is addressed through control lines. Electrically conductive fuses on the segments are used as an interface between the control lines and the die. Segment level programming is performed on each segment by opening the conductive fuses on the segments in a predetermined pattern in order to route the control lines to each segment such that segments are uniquely addressed. After segment level programming, circuit board programming is performed so that any defective die found in the stack is logically replaced with replacement die in the stack.Type: GrantFiled: April 25, 1997Date of Patent: November 30, 1999Assignee: Cubic Memory, Inc.Inventors: David V. Pedersen, Michael G. Finley, Kenneth M. Sautter
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Patent number: 5962910Abstract: 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.Type: GrantFiled: July 17, 1997Date of Patent: October 5, 1999Assignee: Actel CorporationInventors: Frank W. Hawley, Abdelshafy A. Eltoukhy, John L. McCollum
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Patent number: 5920771Abstract: An improved antifuse which employs the base-emitter junction of a silicided single polysilicon bipolar transistor. The distance between the base metal and emitter metal is shortened and results from self aligning process steps rather than lithographic steps, resulting in a lower and better controlled programming voltage, programming energy and ON state resistance. Typically the conductive filament formed in the new antifuse is about 0.65 microns long and is formed by a voltage pulse having a relatively slow rise time (e.g. 150 microseconds), resulting in improved properties which provide advantages in circuit design and in manufacturing circuits using the new antifuse.Type: GrantFiled: March 17, 1997Date of Patent: July 6, 1999Assignee: Gennum CorporationInventors: Petrus T. Appelman, Andrew V. C. Cervin-Lawry, James D. Kendall, Efim Roubakha
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Patent number: 5915171Abstract: An antifuse structure for semiconductor programmable logic devices and the process of fabrication are described. The antifuse structure has its bottom electrically conductive layer featuring sharp corners formed by consumption of the polysilicon material into the sidewall in a thermal oxidation procedure. The sharp corners enhance the intensity of electric field established by a positive bias applied across the top and bottom conductive layers. The sharp corners do not enhance the electric field intensity when a negative bias is applied. This asymmetric conductivity assists in the reduction of the programming voltage as well as the increase of programming speed when the antifuse element is programmed.Type: GrantFiled: December 30, 1997Date of Patent: June 22, 1999Assignee: United Semiconductor Corp.Inventor: Yau-Kae Sheu
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Patent number: 5913137Abstract: A process electrostatic discharge ("ESD") protection device is incorporated on a chip with the antifuses that it is designed to protect and is formed as close in time as possible to the deposition of the antifuse material layer (the layer being protected) so that ESD protection is available at all practical stages of processing. According to a first aspect of the invention, an ESD protection device is formed by exposing edges of an antifuse bottom electrode during the antifuse cell open mask/etch step. It is biased on during processing. A sharp corner of the electrode and a deep aspect ratio provide degrade antifuse performance for the protection cell (resulting in reduced breakdown voltage and increased leakage current) and, as designed, the protection cell will rupture before other cells because it has a lower breakdown voltage. Once the protection cell ruptures, it will continue to conduct and protect other antifuses from ESD damage.Type: GrantFiled: October 1, 1996Date of Patent: June 15, 1999Assignee: Actel CorporationInventor: Wenn-Jei Chen
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Patent number: 5899736Abstract: A method for fabricating an electrically blowable fuse on a semiconductor substrate. The method includes forming a fuse portion 102 on the semiconductor substrate. The fuse portion is configured to turn substantially non-conductive when a current exceeding a predefined current level passes through the fuse portion. The method also includes depositing a substantially conformal first layer 302 of dielectric material above the fuse portion and depositing a second layer 304 of dielectric material above the first layer, thereby forming a protrusion of dielectric material above the fuse portion. The second layer being different from the first layer. The method further includes performing chemical-mechanical polish on the protrusion to form an opening through the second layer above the protrusion. There is also included etching, in a substantially isotropic manner, a portion of the first layer through the opening to form a microcavity 502 about the fuse portion.Type: GrantFiled: September 19, 1997Date of Patent: May 4, 1999Assignee: Siemens AktiengesellschaftInventors: Peter Weigand, Dirk Tobben
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Patent number: 5899707Abstract: An antifuse structure and method for making the antifuse structure having a doped antifuse layer is disclosed. The doped antifuse layer is preferably deposited over a lower electrode. A barrier layer may then be formed over the doped antifuse layer and an upper electrode may subsequently be deposited over the barrier layer. The method of depositing the doped antifuse layer includes: (a) providing a chemical vapor deposition reactor having a support chuck for supporting a partially fabricated silicon wafer; (b) powering up the chemical vapor deposition reactor and heating the partially fabricated silicon wafer; (c) selecting a dopant species for the antifuse layer (e.g, n-type or p-type); (d) introducing a gaseous mixture of a silane compound and the selected dopant species into the chemical vapor deposition reactor with the aid of a neutral species; and (e) depositing the antifuse layer over the lower electrode.Type: GrantFiled: August 20, 1996Date of Patent: May 4, 1999Assignee: VLSI Technology, Inc.Inventors: Ivan Sanchez, Landon B. Vines
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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