Patents by Inventor Alan Christensen
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: 20100252868Abstract: An enhanced FET capable of controlling current above and below a gate of the FET. The FET is formed on a semiconductor substrate. A source and drain are formed in the substrate (or in a well in the substrate). A first epitaxial layer of similar doping to the source and drain are grown on the source and drain, the first epitaxial layer is thicker than the gate, but not so thick as to cover the top of the gate. A second epitaxial layer of opposite doping is grown on the first epitaxial layer thick enough to cover the top of the gate. The portion of the second epitaxial layer above the gate serves as a body through which the gate controls current flow between portions of the first epitaxial layer over the drain and the source.Type: ApplicationFiled: April 1, 2009Publication date: October 7, 2010Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: David Howard Allen, Todd Alan Christensen, David Paul Paulsen, John Edward Sheets, II
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Publication number: 20100214859Abstract: A method and wordline voltage boosting circuit for implementing boosted wordline voltage in memories, and a design structure on which the subject circuit resides are provided. The wordline voltage boosting circuit receives a precharge signal, uses a switching transistor coupled to a bootstrap capacitor, and generates a boosted voltage level responsive to the precharge signal. The boosted voltage level is applied to a voltage supply of an output stage of a wordline driver, causing the wordline voltage level of a selected wordline to be boosted. The switching transistor is controlled by the precharge signal and a node of the bootstrap capacitor supplying the boosted voltage level is driven high by the switching transistor.Type: ApplicationFiled: February 20, 2009Publication date: August 26, 2010Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Derick Gardner Behrends, Todd Alan Christensen, Travis Reynold Hebig, Daniel Mark Nelson
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Publication number: 20100218055Abstract: A method and circuit for implementing substantially perfect array access time tracking with Logic Built In Self Test (LBIST) diagnostics of dynamic memory array and random logic, and a design structure on which the subject circuit resides are provided. The dynamic memory array is initialized to a state for the longest read time for each bit and the dynamic memory array is forced into a read only mode. During LBIST diagnostics with the array in the read only mode, the array outputs are combined with the data inputs to provide random switching data on the array outputs to the random logic.Type: ApplicationFiled: February 26, 2009Publication date: August 26, 2010Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Todd Alan Christensen, Peter Thomas Freiburger, Jesse Daniel Smith
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Publication number: 20100188888Abstract: A method and circuit for implementing an enhanced dual-mode static random access memory (SRAM) performance screen ring oscillator (PSRO), and a design structure on which the subject circuit resides are provided. The dual-mode SRAM PSRO includes a plurality of SRAM base blocks connected together in a chain. Each of the plurality of SRAM base blocks includes an eight-transistor (8T) SRAM cell, a local evaluation circuit and a logic function coupled to the SRAM cell. The eight-transistor (8T) static random access memory (SRAM) cell is an unmodified 8T SRAM cell. The dual-mode SRAM PSRO includes one mode of operation, where the output frequency is determined by write-through performance of the 8T SRAM cell; and another mode of operation, where the output frequency is determined by read performance of the 8T SRAM cell.Type: ApplicationFiled: January 27, 2009Publication date: July 29, 2010Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Chad Allen Adams, Todd Alan Christensen, Peter Thomas Freiburger, Travis Reynold Hebig
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Publication number: 20100187525Abstract: A method and tamper detection circuit for implementing tamper and anti-reverse engineering evident detection in a semiconductor chip, and a design structure on which the subject circuit resides are provided. A capacitor is formed with the semiconductor chip including the circuitry to be protected. A change in the capacitor value results responsive to the semiconductor chip being thinned, which is detected and a tamper-detected signal is generated.Type: ApplicationFiled: January 26, 2009Publication date: July 29, 2010Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Gerald Keith Bartley, Todd Alan Christensen, Paul Eric Dahlen, John Edward Sheets, II
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Publication number: 20100140808Abstract: A first through via is electrically insulated from surrounding wafer substrate material. A second through via is not electrically insulated from the surrounding wafer substrate material. This configuration is advantageous when the non-insulated via serves as the path for either Vdd or GND. By not insulating the through via, a first supply voltage (Vdd or GND) is allowed to flow through the surrounding wafer substrate material thereby decreasing the resistance of the first supply voltage path.Type: ApplicationFiled: February 10, 2010Publication date: June 10, 2010Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Todd Alan Christensen, John Edward Sheets, II
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Patent number: 7727887Abstract: A first through via is electrically insulated from surrounding wafer substrate material. A second through via is not electrically insulated from the surrounding wafer substrate material. This configuration is advantageous when the non-insulated via serves as the path for either Vdd or GND. By not insulating the through via, a first supply voltage (Vdd or GND) is allowed to flow through the surrounding wafer substrate material thereby decreasing the resistance of the first supply voltage path.Type: GrantFiled: October 30, 2007Date of Patent: June 1, 2010Assignee: International Business Machines CorporationInventors: Todd Alan Christensen, John Edward Sheets, II
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Patent number: 7723816Abstract: A method and structures are provided for implementing decoupling capacitors with hot spot thermal reduction on integrated circuit chips including silicon-on-insulator (SOI) circuits. A silicon-on-insulator (SOI) structure includes a silicon substrate layer, a thin buried oxide (BOX) layer carried by the silicon substrate layer, and an active layer carried by the thin BOX layer. A thermal conductive path is built proximate to a hotspot area in the active layer to reduce thermal effects including a backside thermal connection from a backside of the SOI structure. The backside thermal connection includes a backside etched opening extending from the backside of the SOI structure into the silicon substrate layer, a capacitor dielectric formed on said backside etched opening; and a thermal connection material deposited on said capacitor dielectric filling said backside etched opening.Type: GrantFiled: August 6, 2008Date of Patent: May 25, 2010Assignee: International Business Machines CorporationInventors: Gerald Keith Bartley, Todd Alan Christensen, Paul Eric Dahlen, John Edward Sheets, II
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Patent number: 7724586Abstract: A method and circuit for implementing domino static random access memory (SRAM) local evaluation with enhanced SRAM cell stability, and a design structure on which the subject circuit resides are provided. A SRAM local evaluation circuit enabling a read and write operations of an associated SRAM cell group includes true and complement bitlines, true and complement write data propagation inputs, a precharge signal, and a precharge write signal. A respective precharge device is connected between a voltage supply VDD and the true bitline and the complement bitline. A first passgate device is connected between the complement bitline and the true write data propagation input. A second passgate device is connected between the true bitline and the complement write data propagation input. The precharge write signal disables the passgate devices during a read operation. During write operations, the precharge write signal enables the passgate devices.Type: GrantFiled: August 20, 2008Date of Patent: May 25, 2010Assignee: International Business Machines CorporationInventors: Chad Allen Adams, Todd Alan Christensen, Peter Thomas Freiburger, Daniel Mark Nelson
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Patent number: 7715221Abstract: A method and apparatus implementing domino static random access memory (SRAM) leakage current reduction include a local evaluation circuit coupled to true and complement bit lines of a pair of local SRAM cell groups, receives precharge signals and provides an output connected to a global dot line. A sleep input is applied to SRAM sleep logic and a write driver including sleep control. Data true and data complement outputs of the write driver are forced to a respective selected level to discharge the bit lines and global dot lines when the sleep input transitions high. Discharging the bit lines and global dot lines is implemented through gating in the write driver without requiring any additional devices in the local evaluation circuit.Type: GrantFiled: June 23, 2008Date of Patent: May 11, 2010Assignee: International Business Machines CorporationInventors: Todd Alan Christensen, Elizabeth Lair Gerhard, Omer Heymann, Amira Rozenfeld
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Patent number: 7701064Abstract: A first through via is electrically insulated from surrounding wafer substrate material. A second through via is not electrically insulated from the surrounding wafer substrate material. This configuration is advantageous when the non-insulated via serves as the path for either Vdd or GND. By not insulating the through via, a first supply voltage (Vdd or GND) is allowed to flow through the surrounding wafer substrate material thereby decreasing the resistance of the first supply voltage path.Type: GrantFiled: October 31, 2007Date of Patent: April 20, 2010Assignee: International Business Machines CorporationInventors: Todd Alan Christensen, John Edward Sheets, II
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Patent number: 7684263Abstract: A method and circuit for implementing an enhanced static random access memory (SRAM) read and write performance ring oscillator, and a design structure on which the subject circuit resides are provided. A plurality of SRAM base blocks is connected together in a chain. Each of the plurality of SRAM base blocks includes a SRAM cell, such as an eight-transistor (8T) static random access memory (SRAM) cell, and a local evaluation block coupled to the SRAM cell. The SRAM cell includes independent left wordline input and right wordline input. The SRAM cell includes a read wordline connected high, and a true and complement write bitline pair connected low. In the local evaluation circuit, one input of a NAND gate receiving the read bitline input is connected high. A control signal is combined with an inverted feedback signal to start and stop the ring oscillator.Type: GrantFiled: January 17, 2008Date of Patent: March 23, 2010Assignee: International Business Machines CorporationInventors: Chad Allen Adams, Todd Alan Christensen, Peter Thomas Freiburger, Travis Reynold Hebig
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Publication number: 20100046278Abstract: A method and circuit for implementing domino static random access memory (SRAM) local evaluation with enhanced SRAM cell stability, and a design structure on which the subject circuit resides are provided. A SRAM local evaluation circuit enabling a read and write operations of an associated SRAM cell group includes true and complement bitlines, true and complement write data propagation inputs, a precharge signal, and a precharge write signal. A respective precharge device is connected between a voltage supply VDD and the true bitline and the complement bitline. A first passgate device is connected between the complement bitline and the true write data propagation input. A second passgate device is connected between the true bitline and the complement write data propagation input. The precharge write signal disables the passgate devices during a read operation. During write operations, the precharge write signal enables the passgate devices.Type: ApplicationFiled: August 20, 2008Publication date: February 25, 2010Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Chad Allen Adams, Todd Alan Christensen, Peter Thomas Freiburger, Daniel Mark Nelson
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Publication number: 20100032799Abstract: A method and structures are provided for implementing decoupling capacitors with hot spot thermal reduction on integrated circuit chips including silicon-on-insulator (SOI) circuits. A silicon-on-insulator (SOI) structure includes a silicon substrate layer, a thin buried oxide (BOX) layer carried by the silicon substrate layer, and an active layer carried by the thin BOX layer. A thermal conductive path is built proximate to a hotspot area in the active layer to reduce thermal effects including a backside thermal connection from a backside of the SOI structure. The backside thermal connection includes a backside etched opening extending from the backside of the SOI structure into the silicon substrate layer, a capacitor dielectric formed on said backside etched opening; and a thermal connection material deposited on said capacitor dielectric filling said backside etched opening.Type: ApplicationFiled: August 6, 2008Publication date: February 11, 2010Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Gerald Keith Bartley, Todd Alan Christensen, Paul Eric Dahlen, John Edward Sheets, II
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Publication number: 20100019385Abstract: Methods and structures are provided for implementing reduced hot spot thermal effects for silicon-on-insulator (SOI) circuits. A silicon-on-insulator (SOI) structure includes a silicon substrate layer, a thin buried oxide (BOX) layer carried by the silicon substrate layer, an active layer carried by the thin BOX layer, and a pad oxide layer carried by the active layer. A thermal conductive path is built to reduce thermal effects of a hotspot area in the active layer and extends from the active layer to the backside of the SOI structure. A trench etched from the topside to the active layer, and is filled with a thermal connection material. A thermal connection from a backside of the SOI structure includes an opening etched into the silicon substrate layer from the backside and filled with a thermal connection material.Type: ApplicationFiled: July 23, 2008Publication date: January 28, 2010Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Gerald Keith Bartley, Todd Alan Christensen, Paul Eric Dahlen, John Edward Sheets, II
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Publication number: 20090327952Abstract: A method and medium are provided for presenting virtualized visible content within a viewport in a user interface. An anchor is received that represents a point on a line of virtualized visible content and a target value is received that represents a location in a viewport of a user interface. The anchor and target values can be received from user input devices or by analyzing the position of a scroll thumb relative to a scroll trough in the user interface. A first line of virtualized visible content that corresponds to the anchor value is realized by loading the line into memory from another source. The line is then positioned in the viewport based on the target value. Additional lines surrounding the first line are realized until the viewport is full. Lines that are not visible in the viewport can be unrealized, thus conserving computing resources.Type: ApplicationFiled: June 27, 2008Publication date: December 31, 2009Applicant: Microsoft CorporationInventors: Benjamin Karas, Fabrice A. Debry, Jason Alan Christensen
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Patent number: 7626220Abstract: An apparatus and method are disclosed for an improved semiconductor interconnect scheme using a simplified process. In an embodiment of the apparatus, a polysilicon shape is formed on a silicon area. The polysilicon shape is created having a bridging vertex. When a spacer is created on the polysilicon shape, the spacer width is formed to be small enough near the bridging vertex to allow a silicide bridge to form that creates an electrical coupling between the silicon area and the bridging vertex. Semiconductor devices and circuits are created using the improved semiconductor interconnect scheme using the simplified process.Type: GrantFiled: October 22, 2007Date of Patent: December 1, 2009Assignee: International Business Machines CorporationInventors: Todd Alan Christensen, Richard Lee Donze, William Paul Hovis, Terrance Wayne Kueper, John Edward Sheets, II
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Patent number: 7609542Abstract: A method and apparatus including a static random access memory (SRAM) cell implement an enhanced SRAM read performance sort ring oscillator (PSRO), and a design structure on which the subject circuit resides is provided. A pair of parallel reverse polarity connected inverters defines a static latch or cross-coupled memory cell. The SRAM cell includes independent left and right wordlines providing a respective gate input to a pair of access transistors used to access to the memory cell. The SRAM cell includes a voltage supply connection to one side of the static latch. For example, a complement side of the static latch is connected to the voltage supply. A plurality of the SRAM cells is assembled together to form a SRAM base block. A plurality of the SRAM base blocks is connected together to form the SRAM read PSRO.Type: GrantFiled: October 17, 2007Date of Patent: October 27, 2009Assignee: International Business Machines CorporationInventors: Chad Allen Adams, Todd Alan Christensen, Travis Reynold Hebig, Kirk David Peterson
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Publication number: 20090185435Abstract: A method and circuit for implementing an enhanced static random access memory (SRAM) read and write performance ring oscillator, and a design structure on which the subject circuit resides are provided. A plurality of SRAM base blocks is connected together in a chain. Each of the plurality of SRAM base blocks includes a SRAM cell, such as an eight-transistor (8T) static random access memory (SRAM) cell, and a local evaluation block coupled to the SRAM cell. The SRAM cell includes independent left wordline input and right wordline input. The SRAM cell includes a read wordline connected high, and a true and complement write bitline pair connected low. In the local evaluation circuit, one input of a NAND gate receiving the read bitline input is connected high. A control signal is combined with an inverted feedback signal to start and stop the ring oscillator.Type: ApplicationFiled: January 17, 2008Publication date: July 23, 2009Inventors: Chad Allen Adams, Todd Alan Christensen, Peter Thomas Freiburger, Travis Reynold Hebig
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Publication number: 20090183044Abstract: A method and circuit implement testing of a circuit path including a memory array and logic including Logic Built in Self Test (LBIST) diagnostics, and a design structure on which the subject circuit resides are provided. Testing of the circuit path includes initializing the memory array in the circuit path with an initialization pattern, switching to Logic Built in Self Test (LBIST) mode and providing a read only mode for the memory array, and running Logic Built in Self Test (LBIST) testing of the circuit path.Type: ApplicationFiled: January 16, 2008Publication date: July 16, 2009Inventors: Louis Bernard Bushard, Todd Alan Christensen, Jesse Daniel Smith