Patents by Inventor John M. Safran
John M. Safran has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8361887Abstract: An antifuse having a link including a region of unsilicided semiconductor material may be programmed at reduced voltage and current and with reduced generation of heat by electromigration of metal or silicide from a cathode into the region of unsilicided semiconductor material to form an alloy having reduced bulk resistance. The cathode and anode are preferably shaped to control regions from which and to which material is electrically migrated. After programming, additional electromigration of material can return the antifuse to a high resistance state. The process by which the antifuse is fabricated is completely compatible with fabrication of field effect transistors and the antifuse may be advantageously formed on isolation structures.Type: GrantFiled: January 31, 2012Date of Patent: January 29, 2013Assignee: International Business Machines CorporationInventors: Alberto Cestero, Byeongju Park, John M. Safran
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Patent number: 8350264Abstract: An antifuse is provided having a unitary monocrystalline semiconductor body including first and second semiconductor regions each having the same first conductivity type, and a third semiconductor region between the first and second semiconductor regions which has a second conductivity type opposite from the first conductivity type. An anode and a cathode can be electrically connected with the first semiconductor region. A conductive region including a metal, a conductive compound of a metal or an alloy of a metal can contact the first semiconductor region and extend between the cathode and the anode. The antifuse can further include a contact electrically connected with the second semiconductor region.Type: GrantFiled: July 14, 2010Date of Patent: January 8, 2013Assignee: International Businesss Machines CorporationInventors: Yan Zun Li, Chandrasekharan Kothandaraman, Dan Moy, Norman W. Robson, John M. Safran
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Publication number: 20120171857Abstract: A fabrication method for fabricating an electrically programmable fuse method includes depositing a polysilicon layer on a substrate, patterning an anode contact region, a cathode contact region and a fuse link conductively connecting the cathode contact region with the anode contact region, which is programmable by applying a programming current, depositing a silicide layer on the polysilicon layer, and forming a plurality of anisometric contacts on the silicide layer of the cathode contact region and the anode contact region in a predetermined configuration, respectively.Type: ApplicationFiled: March 15, 2012Publication date: July 5, 2012Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Chandrasekharan Kothandaraman, Dan Moy, Norman W. Robson, John M. Safran
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Publication number: 20120129319Abstract: An antifuse having a link including a region of unsilicided semiconductor material may be programmed at reduced voltage and current and with reduced generation of heat by electromigration of metal or silicide from a cathode into the region of unsilicided semiconductor material to form an alloy having reduced bulk resistance. The cathode and anode are preferably shaped to control regions from which and to which material is electrically migrated. After programming, additional electromigration of material can return the antifuse to a high resistance state. The process by which the antifuse is fabricated is completely compatible with fabrication of field effect transistors and the antifuse may be advantageously formed on isolation structures.Type: ApplicationFiled: January 31, 2012Publication date: May 24, 2012Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Alberto Cestero, Byeongju Park, John M. Safran
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Patent number: 8115275Abstract: An antifuse having a link including a region of unsilicided semiconductor material may be programmed at reduced voltage and current and with reduced generation of heat by electromigration of metal or silicide from a cathode into the region of unsilicided semiconductor material to form an alloy having reduced bulk resistance. The cathode and anode are preferably shaped to control regions from which and to which material is electrically migrated. After programming, additional electromigration of material can return the antifuse to a high resistance state. The process by which the antifuse is fabricated is completely compatible with fabrication of field effect transistors and the antifuse may be advantageously formed on isolation structures.Type: GrantFiled: September 8, 2009Date of Patent: February 14, 2012Assignee: International Business Machines CorporationInventors: Alberto Cestero, Byeongju Park, John M. Safran
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Publication number: 20120012977Abstract: An antifuse is provided having a unitary monocrystalline semiconductor body including first and second semiconductor regions each having the same first conductivity type, and a third semiconductor region between the first and second semiconductor regions which has a second conductivity type opposite from the first conductivity type. An anode and a cathode can be electrically connected with the first semiconductor region. A conductive region including a metal, a conductive compound of a metal or an alloy of a metal can contact the first semiconductor region and extend between the cathode and the anode. The antifuse can further include a contact electrically connected with the second semiconductor region.Type: ApplicationFiled: July 14, 2010Publication date: January 19, 2012Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Yan Zun Li, Chandrasekharan Kothandaraman, Dan Moy, Norman W. Robson, John M. Safran
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Patent number: 8004060Abstract: A metal layer and a semiconductor layer are sequentially deposited on a substrate. The semiconductor layer and the metal layer are lithographically patterned to form a stack of a semiconductor portion and a metal gate portion, which is preferably performed concurrently with formation of at least one metal gate stack. In one embodiment, the size of the semiconductor portion is reduced and a metal semiconductor alloy portion is formed on the semiconductor portion by metallization. In a first electrical antifuse formed thereby, the metal semiconductor alloy portion may be electromigrated to form a short between the metal semiconductor alloy portion and the metal gate portion. In another embodiment, two disjoined metal semiconductor alloy portions are formed on the semiconductor portion. In a second electrical antifuse formed thereby, the metal semiconductor alloy portion may be electromigrated to form a short between the two previously disjoined metal semiconductor alloy portions.Type: GrantFiled: November 29, 2007Date of Patent: August 23, 2011Assignee: International Business Machines CorporationInventors: Deok-kee Kim, Chandrasekharan Kothandaraman, Dan Moy, Norman W. Robson, John M. Safran, Kenneth J. Stein
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Publication number: 20100327399Abstract: An electrically programmable fuse that includes an anode contact region and a cathode contact region are formed of a polysilicon layer having a silicide layer formed thereon, and a fuse link conductively connecting the cathode contact region with the anode contact region, which is programmable by applying a programming current, and a plurality of anisometric contacts formed on the silicide layer of the cathode contact region or on both the silicide layer of the cathode contact region and the anode contact region in a predetermined configuration, respectively.Type: ApplicationFiled: June 29, 2009Publication date: December 30, 2010Applicant: International Business Machines CorporationInventors: CHANDRASEKHARAN KOTHANDARAMAN, DAN MOY, NORMAN W. ROBSON, JOHN M. SAFRAN
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Patent number: 7817455Abstract: A one-time-programmable-read-only-memory (OTPROM) is implemented in a two-dimensional array of aggressively scaled suicide migratable e-fuses. Word line selection is performed by decoding logic operating at VDD while the bit line drive is switched between VDD and a higher voltage, Vp, for programming. The OTPROM is thus compatible with and can be integrated with other technologies without a cost adder and supports optimization of the high current path for minimal voltage drop during fuse programming. A differential sense amplifier with a programmable reference is used for improved sense margins and can support an entire bit line rather than sense amplifiers being provided for individual fuses.Type: GrantFiled: August 30, 2006Date of Patent: October 19, 2010Assignee: International Business Machines CorporationInventors: Gregory J. Fredeman, Toshiaki Kirihata, Alan J. Leslie, John M. Safran
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Patent number: 7723820Abstract: The present invention provides structures for an integrated antifuse that incorporates an integrated sensing transistor with an integrated heater. Two terminals connected to the upper plate allow the heating of the upper plate, accelerating the breakdown of the antifuse dielectric at a lower bias voltage. Part of the upper plate also serves as the gate of the integrated sensing transistor. The antifuse dielectric serves as the gate dielectric of the integrated transistor. The lower plate comprises a channel, a drain, and a source of a transistor. While intact, the integrated sensing transistor allows a passage of transistor current through the drain. When programmed, the antifuse dielectric, which is the gate of the integrated transistor, is subjected to a gate breakdown, shorting the gate to the channel and resulting in a decreased drain current. The integrated antifuse structure can also be wired in an array to provide a compact OTP memory array.Type: GrantFiled: December 28, 2006Date of Patent: May 25, 2010Assignee: International Business Machines CorporationInventors: Deok-kee Kim, Byeongju Park, John M. Safran
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Patent number: 7714326Abstract: The present invention provides structures for antifuses that utilize electromigration for programming. By providing a portion of antifuse link with high resistance without conducting material and then by inducing electromigration of the conducting material into the antifuse link, the resistance of the antifuse structure is changed. By providing a terminal on the antifuse link, the change in the electrical properties of the antifuse link is detected and sensed. Also disclosed are an integrated antifuse with a built-in sensing device and a two dimensional array of integrated antifuses that can share programming transistors and sensing circuitry.Type: GrantFiled: March 7, 2007Date of Patent: May 11, 2010Assignee: International Business Machines CorporationInventors: Deok-kee Kim, Hoki Kim, Chandrasekharan Kothandaraman, Byeongju Park, John M. Safran
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Patent number: 7700993Abstract: A CMOS EPROM, EEPROM or inverter device includes an nFET device with a thin gate dielectric layer and a pFET device juxtaposed with the nFET device with a thick gate dielectric layer and a floating gate electrode. The thick gate dielectric layer is substantially thicker than the thin gate dielectric layer. A common drain node connected both FET devices has no external connection in the case of a memory device and has an external connection in the case of an inverter. There are external circuit connections to the source regions of both FET devices and to the gate electrode of the nFET device. The pFET and nFET devices can be planar, vertical or FinFET devices.Type: GrantFiled: November 5, 2007Date of Patent: April 20, 2010Assignee: International Business Machines CorporationInventors: Jin Cai, Tak H. Ning, John M. Safran
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Patent number: 7674691Abstract: An antifuse having a link including a region of unsilicided semiconductor material may be programmed at reduced voltage and current and with reduced generation of heat by electromigration of metal or silicide from a cathode into the region of unsilicided semiconductor material to form an alloy having reduced bulk resistance. The cathode and anode are preferably shaped to control regions from which and to which material is electrically migrated. After programming, additional electromigration of material can return the antifuse to a high resistance state. The process by which the antifuse is fabricated is completely compatible with fabrication of field effect transistors and the antifuse may be advantageously formed on isolation structures.Type: GrantFiled: March 7, 2007Date of Patent: March 9, 2010Assignee: International Business Machines CorporationInventors: Alberto Cestero, Byeongju Park, John M. Safran
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Publication number: 20090321735Abstract: An antifuse having a link including a region of unsilicided semiconductor material may be programmed at reduced voltage and current and with reduced generation of heat by electromigration of metal or silicide from a cathode into the region of unsilicided semiconductor material to form an alloy having reduced bulk resistance. The cathode and anode are preferably shaped to control regions from which and to which material is electrically migrated. After programming, additional electromigration of material can return the antifuse to a high resistance state. The process by which the antifuse is fabricated is completely compatible with fabrication of field effect transistors and the antifuse may be advantageously formed on isolation structures.Type: ApplicationFiled: September 8, 2009Publication date: December 31, 2009Inventors: Alberto Cestero, Byeongju Park, John M. Safran
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Patent number: 7609577Abstract: A design structure embodied in a machine readable medium used in a design process includes an apparatus for sensing the state of a programmable resistive memory element device, the apparatus further including a latch device coupled to a fuse node and a reference node, the fuse node included within a fuse leg and the reference node configured within a reference resistance leg, the latch device configured to detect a differential signal developed between the reference node and the fuse node as the result of sense current passed through the fuse leg and the reference resistance leg; and the fuse and reference resistance legs further configured for first and second sensing modes, wherein the second sensing mode utilizes a different level of current than the first sensing mode.Type: GrantFiled: October 15, 2007Date of Patent: October 27, 2009Assignee: International Business Machines CorporationInventors: Darren L. Anand, Gregory J. Fredeman, Toshiaki Kirihata, Alan J. Leslie, John M. Safran
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Publication number: 20090141533Abstract: A metal layer and a semiconductor layer are sequentially deposited on a substrate. The semiconductor layer and the metal layer are lithographically patterned to form a stack of a semiconductor portion and a metal gate portion, which is preferably performed concurrently with formation of at least one metal gate stack. In one embodiment, the size of the semiconductor portion is reduced and a metal semiconductor alloy portion is formed on the semiconductor portion by metallization. In a first electrical antifuse formed thereby, the metal semiconductor alloy portion may be electromigrated to form a short between the metal semiconductor alloy portion and the metal gate portion. In another embodiment, two disjoined metal semiconductor alloy portions are formed on the semiconductor portion. In a second electrical antifuse formed thereby, the metal semiconductor alloy portion may be electromigrated to form a short between the two previously disjoined metal semiconductor alloy portions.Type: ApplicationFiled: November 29, 2007Publication date: June 4, 2009Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Deok-kee Kim, Chandrasekharan Kothandaraman, Dan Moy, Norman W. Robson, John M. Safran, Kenneth J. Stein
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Publication number: 20090114971Abstract: A CMOS EPROM, EEPROM or inverter device includes an nFET device with a thin gate dielectric layer and a pFET device juxtaposed with the nFET device with a thick gate dielectric layer and a floating gate electrode. The thick gate dielectric layer is substantially thicker than the thin gate dielectric layer. A common drain node connected both FET devices has no external connection in the case of a memory device and has an external connection in the case of an inverter. There are external circuit connections to the source regions of both FET devices and to the gate electrode of the nFET device. The pFET and nFET devices can be planar, vertical or FinFET devices.Type: ApplicationFiled: November 5, 2007Publication date: May 7, 2009Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Jin Cai, Tak H. Ning, John M. Safran
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Patent number: 7525831Abstract: A method for determining the state of a programmable resistive memory element includes passing a first level of current through a fuse leg and a reference resistance leg of a test circuit including the programmable resistive memory element; detecting a differential signal developed between a reference node and a fuse node of the test circuit as a result of the first level of current; passing a second level of current through the fuse leg and the reference leg of a test circuit, the second level of current being higher than the first level of current so as to enable detection of trip resistance of the test circuit at a lower value than with respect to the first level of current; and detecting a differential signal developed between the reference node and the fuse node of the test circuit as a result of the second level of current.Type: GrantFiled: October 5, 2007Date of Patent: April 28, 2009Assignee: International Business Machines CorporationInventors: Darren L. Anand, Gregory J. Fredeman, Toshiaki Kirihata, Alan J. Leslie, John M. Safran
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Publication number: 20080316789Abstract: A one-time-programmable-read-only-memory (OTPROM) is implemented in a two-dimensional array of aggressively scaled suicide migratable e-fuses. Word line selection is performed by decoding logic operating at VDD while the bit line drive is switched between VDD and a higher voltage, Vp for programming. The OTPROM is thus compatible with and can be integrated with other technologies without a cost adder and supports optimization of the high current path for minimal voltage drop during fuse programming. A differential sense amplifier with a programmable reference is used for improved sense margins and can support an entire bit line rather than sense amplifiers being provided for individual fuses.Type: ApplicationFiled: August 30, 2006Publication date: December 25, 2008Inventors: Gregory J. Fredeman, Toshiaki Kirihata, Alan J. Leslie, John M. Safran
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Publication number: 20080217658Abstract: The present invention provides structures for antifuses that utilize electromigration for programming. By providing a portion of antifuse link with high resistance without conducting material and then by inducing electromigration of the conducting material into the antifuse link, the resistance of the antifuse structure is changed. By providing a terminal on the antifuse link, the change in the electrical properties of the antifuse link is detected and sensed. Also disclosed are an integrated antifuse with a built-in sensing device and a two dimensional array of integrated antifuses that can share programming transistors and sensing circuitry.Type: ApplicationFiled: March 7, 2007Publication date: September 11, 2008Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Deok-kee Kim, Hoki Kim, Chandrasekharan Kothandaraman, Byeongju Park, John M. Safran