Patents by Inventor Todd Alan Christensen
Todd Alan Christensen 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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Publication number: 20040070433Abstract: A pulse generator circuit is disclosed including a delay element coupled to a logic circuit. The delay element receives a clock signal CLK and a signal X and produces a signal XN dependent upon the clock signal CLK and the signal X. The logic circuit receives the clock signal CLK and the signal XN and produces a signal ACLK such that ACLK=CLK·XN′. The signal ACLK may include a series of positive pulses. The delay element may be, for example, one of multiple delay elements coupled in series, and signal X may be an output of a preceding one of the delay elements. A semiconductor device is described including the above pulse generator circuit and a self-resetting logic circuit. The self-resetting logic circuit receives the signal ACLK and one or more input signals and performs a logic operation using the one or more input signals during the positive pulses.Type: ApplicationFiled: October 10, 2002Publication date: April 15, 2004Applicant: International Business Machines CorporationInventors: Chad Allen Adams, Todd Alan Christensen, Peter Thomas Freiburger
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Patent number: 6670716Abstract: Silicon-on-insulator (SOI) semiconductor structures are provided for implementing transistor source connections for SOI transistor devices using buried dual rail distribution. A SOI semiconductor structure includes a SOI transistor having a silicide layer covering a SOI transistor source, a predefined buried conduction layer to be connected to a SOI transistor source, and an intermediate conduction layer between the SOI transistor and the predefined buried conduction layer. A first hole for a transistor source connection to a local interconnect is anisotropically etched in the SOI semiconductor structure to the silicide layer covering the SOI transistor source. A second hole aligned with the local interconnect hole is anisotropically etched through the SOI semiconductor structure to the predefined buried conduction layer. An insulator is disposed between the second hole and the intermediate conduction layer.Type: GrantFiled: August 22, 2002Date of Patent: December 30, 2003Assignee: International Business Machines CorporationInventors: Todd Alan Christensen, John Edward Sheets, II, Gregory John Uhlmann
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Patent number: 6667518Abstract: Methods and semiconductor structures are provided for implementing buried dual rail power distribution and integrated decoupling capacitance for silicon on insulator (SOI) devices. A bulk silicon substrate layer is provided that defines one power distribution rail. A high energy deep oxygen implant is performed to create a deep buried oxide layer and a first intermediate silicon layer. The deep buried oxide layer is disposed between the bulk silicon substrate layer and the first intermediate silicon layer. The first intermediate silicon layer defines another power distribution rail. A lower energy oxygen implant is performed to create a shallow buried oxide layer and a second intermediate silicon layer. The shallow buried oxide layer is disposed between the first intermediate silicon layer and the second intermediate silicon layer. A connection to the bulk silicon substrate layer is formed without making electrical connection to the intermediate silicon layers.Type: GrantFiled: August 9, 2002Date of Patent: December 23, 2003Assignee: International Business Machines CorporationInventors: Todd Alan Christensen, John Edward Sheets, II
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Patent number: 6657886Abstract: A high performance domino static random access memory (SRAM) is provided. The domino SRAM includes a plurality of local cell groups. Each of the plurality of local cell groups includes a plurality of SRAM cells and a local true bitline coupled to each of the plurality of SRAM cells of each local cell group. A continuous complement bitline is coupled to each of the plurality of local cell groups and is coupled to each of the plurality of SRAM cells of each local cell group. For a write to the SRAM cell complement node, only driving the continuous complement bitline is required. The domino SRAM reduces the number of required wires and required transistors as compared to prior art domino SRAM and thus the area needed and power consumption are reduced for the domino SRAM.Type: GrantFiled: May 7, 2002Date of Patent: December 2, 2003Assignee: International Business Machines CorporationInventors: Chad Allen Adams, Anthony Gus Aipperspach, Todd Alan Christensen, Peter Thomas Freiburger
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Publication number: 20030210565Abstract: A high performance domino static random access memory (SRAM) is provided. The domino SRAM includes a plurality of local cell groups. Each of the plurality of local cell groups includes a plurality of SRAM cells and a local true bitline coupled to each of the plurality of SRAM cells of each local cell group. A continuous complement bitline is coupled to each of the plurality of local cell groups and is coupled to each of the plurality of SRAM cells of each local cell group. For a write to the SRAM cell complement node, only driving the continuous complement bitline is required. The domino SRAM reduces the number of required wires and required transistors as compared to prior art domino SRAM and thus the area needed and power consumption are reduced for the domino SRAM.Type: ApplicationFiled: May 7, 2002Publication date: November 13, 2003Applicant: International Business Machines CorporationInventors: Chad Allen Adams, Anthony Gus Aipperspach, Todd Alan Christensen, Peter Thomas Freiburger
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Patent number: 6645796Abstract: A method and semiconductor structure including silicon-on-insulator (SOI) devices are provided for implementing reach through buried interconnect. A semiconductor stack includes a predefined buried conductor to be connected through multiple insulator layers and at least one intermediate conductor above the predefined buried conductor. A hole is anisotropically etched through the semiconductor stack to the predefined buried conductor. The etched hole extends through the at least one intermediate conductor and the insulators to the predefined buried conductor in the semiconductor stack. A thin layer of insulator is deposited over an interior of the etched hole. The deposited thin insulator layer is anisotropically etched to remove the deposited thin insulator layer from a bottom of the hole exposing the predefined buried conductor in the semiconductor stack with the thin insulator layer covering sidewalls of the hole to define an insulated opening.Type: GrantFiled: November 21, 2001Date of Patent: November 11, 2003Assignee: International Business Machines CorporationInventors: Todd Alan Christensen, John Edward Sheets, II
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Publication number: 20030205759Abstract: A method and apparatus for reducing parasitic bipolar transistor leakage current in a Silicon on Insulator (SOI) Metal Oxide Semiconductor (MOS). A capacitor is operatively coupled between the base and emitter terminals of the parasitic bipolar transistor. The capacitor effectively reduces the base to emitter voltage of the parasitic transistor thereby reducing leakage current generated at the collector terminal.Type: ApplicationFiled: October 23, 2001Publication date: November 6, 2003Applicant: International Business Machines CorporationInventors: Todd Alan Christensen, David Michael Friend, Nghia Van Phan, John Edward Sheets
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Patent number: 6643804Abstract: An apparatus, program product, and method of testing a silicon-on-insulator (SOI) static random access memory (SRAM) introduce switching history effects to a memory cell during testing to stress the memory cell such that a reliable determination of stability may be made. Stress is applied to a memory cell through the use of a bitline precharge stress operation, which utilizes the bitline pairs coupled to a memory cell to attempt to flood the memory cell with charge and thereby attempt to cause the memory cell to unexpectedly switch state. The bitline precharge stress operation is performed immediately after the memory cell has been switched to one state after being maintained in an opposite state for a length of time that is sufficient to introduce switching history effects to the memory cell.Type: GrantFiled: April 19, 2000Date of Patent: November 4, 2003Assignee: International Business Machines CorporationInventors: Anthony Gus Aipperspach, Todd Alan Christensen, Douglas Michael Dewanz
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Publication number: 20030170936Abstract: Methods and silicon-on-insulator (SOI) semiconductor structures are provided for implementing transistor source connections for SOI transistor devices using buried dual rail distribution. A SOI semiconductor structure includes a SOI transistor having a silicide layer covering a SOI transistor source, a predefined buried conduction layer to be connected to a SOI transistor source, and an intermediate conduction layer between the SOI transistor and the predefined buried conduction layer. A first hole for a transistor source connection to a local interconnect is anisotropically etched in the SOI semiconductor structure to the silicide layer covering the SOI transistor source. A second hole aligned with the local interconnect hole is anisotropically etched through the SOI semiconductor structure to the predefined buried conduction layer. An insulator is disposed between the second hole and the intermediate conduction layer.Type: ApplicationFiled: August 22, 2002Publication date: September 11, 2003Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Todd Alan Christensen, John Edward Sheets, Gregory John Uhlmann
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Publication number: 20030123279Abstract: An SRAM memory cell made with increased stability using SOI technology is provided. Increased stability results from a decreased threshold voltage of the pullup pfets included in the inverter. Preferably the decrease of threshold voltage is achieved using a decreased concentration of phosphorus, antimony, arsenic, or other n-type ions during implantation.Type: ApplicationFiled: January 3, 2002Publication date: July 3, 2003Applicant: International Business Machines CorporationInventors: Anthony Gus Aipperspach, Todd Alan Christensen
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Patent number: 6570433Abstract: A method and apparatus are provided for laser fuseblow protection in transistors, such as silicon-on-insulator (SOI) transistors. The transistors are connected to a fuse. A pair of diodes are connected in series between a high supply and ground. A common connection of the series connected pair of diodes is connected to a common connection of the fuse and transistors. A charge is shunted to the high supply or ground by the pair of diodes with a first voltage a set value above the high supply and a second voltage a set value below the ground. A pair of protection diodes are provided on each side of the fuse with transistors. The transistors are either connected to one side of the fuse or to both sides of the fuse.Type: GrantFiled: August 9, 2001Date of Patent: May 27, 2003Assignee: International Business Machines CorporationInventors: Anthony Gus Aipperspach, Todd Alan Christensen
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Publication number: 20030094653Abstract: A method and semiconductor structure including silicon-on-insulator (SOI) devices are provided for implementing reach through buried interconnect. A semiconductor stack includes a predefined buried conductor to be connected through multiple insulator layers and at least one intermediate conductor above the predefined buried conductor. A hole is anisotropically etched through the semiconductor stack to the predefined buried conductor. The etched hole extends through the at least one intermediate conductor and the insulators to the predefined buried conductor in the semiconductor stack. A thin layer of insulator is deposited over an interior of the etched hole. The deposited thin insulator layer is anisotropically etched to remove the deposited thin insulator layer from a bottom of the hole exposing the predefined buried conductor in the semiconductor stack with the thin insulator layer covering sidewalls of the hole to define an insulated opening.Type: ApplicationFiled: November 21, 2001Publication date: May 22, 2003Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Todd Alan Christensen, John Edward Sheet
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Publication number: 20030094654Abstract: Methods and semiconductor structures are provided for implementing buried dual rail power distribution and integrated decoupling capacitance for silicon on insulator (SOI) devices. A bulk silicon substrate layer is provided that defines one power distribution rail. A high energy deep oxygen implant is performed to create a deep buried oxide layer and a first intermediate silicon layer. The deep buried oxide layer is disposed between the bulk silicon substrate layer and the first intermediate silicon layer. The first intermediate silicon layer defines another power distribution rail. A lower energy oxygen implant is performed to create a shallow buried oxide layer and a second intermediate silicon layer The shallow buried oxide layer is disposed between the first intermediate silicon layer and the second intermediate silicon layer. A connection to the bulk silicon substrate layer is formed without making electrical connection to the intermediate silicon layers.Type: ApplicationFiled: August 9, 2002Publication date: May 22, 2003Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Todd Alan Christensen, John Edward Sheets
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Publication number: 20030071692Abstract: Measurement methods and a ring oscillator circuit are provided for evaluating dynamic circuits. The ring oscillator circuit includes a one-shot pulse generator receiving a single transition input signal and producing a pulse output signal having a rising transition and falling transition. The dynamic circuit to be evaluated is coupled to an output of the one-shot pulse generator receiving the pulse output signal of the one-shot pulse generator and producing a delayed output pulse at an output. A divide-by-two circuit is coupled to the output of the dynamic circuit to be evaluated. An output signal of the divide-by-two circuit is fed back to the one-shot pulse generator, and the cycle is repeated, thus oscillating. A multiplexer is connected between output of the dynamic circuit to be evaluated and the divide-by-two circuit.Type: ApplicationFiled: October 15, 2001Publication date: April 17, 2003Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Anthony Gus Aipperspach, Todd Alan Christensen, Peter Thomas Freiburger, David Michael Friend, Nghia Van Phan
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Publication number: 20030058675Abstract: An SRAM memory cell made with increased stability using SOI technology is provided. Increased stability occurs because of raising the threshold voltage of the transfer nfets connected to the word line. Preferably the increase of threshold voltage is achieved using boron ion implantation.Type: ApplicationFiled: September 25, 2001Publication date: March 27, 2003Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Anthony Gus Aipperspach, Andres Bryant, Todd Alan Christensen, Dennis T. Cox, Jerome Brett Lasky, John Edward Sheets, Francis Roger White
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Patent number: 6538522Abstract: Measurement methods and a ring oscillator circuit are provided for evaluating dynamic circuits. The ring oscillator circuit includes a one-shot pulse generator receiving a single transition input signal and producing a pulse output signal having a rising transition and falling transition. The dynamic circuit to be evaluated is coupled to an output of the one-shot pulse generator receiving the pulse output signal of the one-shot pulse generator and producing a delayed output pulse at an output. A divide-by-two circuit is coupled to the output of the dynamic circuit to be evaluated. An output signal of the divide-by-two circuit is fed back to the one-shot pulse generator, and the cycle is repeated, thus oscillating. A multiplexer is connected between output of the dynamic circuit to be evaluated and the divide-by-two circuit.Type: GrantFiled: October 15, 2001Date of Patent: March 25, 2003Assignee: International Business Machines CorporationInventors: Anthony Gus Aipperspach, Todd Alan Christensen, Peter Thomas Freiburger, David Michael Friend, Nghia Van Phan
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Patent number: 6528853Abstract: A method and semiconductor structure are provided for implementing dual plane body contacts for silicon-on-insulator (SOI) transistors. A bulk silicon substrate is provided. A deep ion implant layer is implanted to reside below an oxide insulator. An oxygen implant layer is implanted while applying a mask to block the oxygen implant layer in selected regions. The selected regions provide for body contact for the SOI transistors. Holes are formed extending into the deep ion implant layer and the bulk silicon substrate. The holes are filled with an electrically conductive material to create stud contacts to the deep ion implant layer and the bulk silicon substrate.Type: GrantFiled: May 31, 2001Date of Patent: March 4, 2003Assignee: International Business Machines CorporationInventors: Todd Alan Christensen, John Edward Sheets, II
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Patent number: 6509236Abstract: A method and apparatus are provided for laser fuseblow protection in transistors, such as silicon-on-insulator (SOI) transistors. The transistors are connected to a fuse. A pair of diodes are connected in series between a high supply and ground. A common connection of the series connected pair of diodes is connected to a common connection of the fuse and transistors. A charge is shunted to the high supply or ground by the pair of diodes with a first voltage a set value above the high supply and a second voltage a set value below the ground. A pair of protection diodes are provided on each side of the fuse with transistors. The transistors are either connected to one side of the fuse or to both sides of the fuse.Type: GrantFiled: June 6, 2000Date of Patent: January 21, 2003Assignee: International Business Machines CorporationInventors: Anthony Gus Aipperspach, Todd Alan Christensen
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Patent number: 6498057Abstract: Methods and silicon-on-Insulator (SOI) semiconductor structures are provided for implementing transistor source connections for SOI transistor devices using buried dual rall distribution. A SOI semiconductor structure Includes a SOI transistor having a silicide layer covering a SOI transistor source, a predefined burled conduction layer to be connected to a SOI transistor source, and an Intermediate conduction layer between the SOI transistor and the predefined buried conduction layer, A first hole for a transistor source connection to a local interconnect is anisotropically etched in the SOI semiconductor structure to the silcide layer covering the SOI transistor source. A second hole aligned with the local interconnect hole is anisotropically etched through the SOI semiconductor structure to the predefined buried conduction layer. An Insulator is disposed between the second hole and the intermediate conduction layer.Type: GrantFiled: March 7, 2002Date of Patent: December 24, 2002Assignee: International Business Machines CorporationInventors: Todd Alan Christensen, John Edward Sheets, II, Gregory John Uhlmann
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Patent number: 6492244Abstract: Methods and semiconductor structures are provided for implementing buried dual rail power distribution and integrated decoupling capacitance for silicon on insulator (SOI) devices. A bulk silicon substrate layer is provided that defines one power distribution rail. A high energy deep oxygen implant is performed to create a deep buried oxide layer and a first intermediate silicon layer. The deep buried oxide layer is disposed between the bulk silicon substrate layer and the first intermediate silicon layer. The first intermediate silicon layer defines another power distribution rail. A lower energy oxygen implant is performed to create a shallow buried oxide layer and a second intermediate silicon layer. The shallow buried oxide layer is disposed between the first intermediate silicon layer and the second intermediate silicon layer. A connection to the bulk silicon substrate layer is formed without making electrical connection to the intermediate silicon layers.Type: GrantFiled: November 21, 2001Date of Patent: December 10, 2002Assignee: International Business Machines CorporationInventors: Todd Alan Christensen, John Edward Sheets, II