Patents by Inventor Steven W. Longcor

Steven W. Longcor 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).

  • Patent number: 7009235
    Abstract: A conductive memory stack is provided. The memory stack includes a bottom electrode, a top electrode and a multi-resistive state element that is sandwiched between the electrodes. The bottom electrode can be described as having a top face with a first surface area, the top electrode has a bottom face with a second surface area and the multi-resistive state element has a bottom face with a third surface area and a top face with a fourth surface area. The multi-resistive state element's bottom face is in contact with the bottom electrode's top face and the multi-resistive state element's top face is in contact with the top electrode's bottom face. Furthermore, the fourth surface area is not equal to the second surface area.
    Type: Grant
    Filed: November 10, 2003
    Date of Patent: March 7, 2006
    Inventors: Darrell Rinerson, Steven W. Longcor, Christophe J. Chevallier
  • Patent number: 6972985
    Abstract: A memory including a memory element having islands is provided. The memory has address decoding circuitry and an array of memory plugs. The memory plugs include memory element that have island structures of a first material within the bulk of a second material. The island structures are typically nanoparticles. The memory plugs can be placed in a first resistive state at a first write voltage, placed in a second resistive state at a second write voltage, and have its resistive state determined at a read voltage.
    Type: Grant
    Filed: June 15, 2004
    Date of Patent: December 6, 2005
    Inventors: Darrell Rinerson, Christophe J. Chevallier, Philip F. S. Swab, Steve Kuo-Ren Hsia, John E. Sanchez, Jr., Steven W. Longcor
  • Patent number: 6970375
    Abstract: Providing a reference voltage to a cross point memory array. The invention is a cross point memory array and some peripheral circuitry that, when activated, provides a reference voltage to a cross point array in order to prevent unselected conductive array lines from floating to an undesired voltage. The peripheral circuitry can be activated before, after or during selection of a specific memory plug. If the peripheral circuitry is activated during selection, only the unselected conductive array lines should be brought to the reference voltage. Otherwise, all the conductive array lines can be brought to the reference voltage.
    Type: Grant
    Filed: December 26, 2002
    Date of Patent: November 29, 2005
    Inventors: Darrell Rinerson, Christophe J. Chevallier, Steven W. Longcor, Edmond R. Ward, Wayne Kinney, Steve Kuo-Ren Hsia
  • Patent number: 6965137
    Abstract: A multilayered conductive memory device capable of storing information individually or as part of an array of memory devices is provided. Boundary control issues at the interface between layers of the device due to the use of incompatible materials can be avoided by intentionally doping the conductive metal oxide layers that are comprised of substantially similar materials. Methods of manufacture are also provided herein.
    Type: Grant
    Filed: October 23, 2003
    Date of Patent: November 15, 2005
    Inventors: Wayne Kinney, Steven W. Longcor, Darrell Rinerson, Steve Kuo-Ren Hsia
  • Patent number: 6917539
    Abstract: High density NVRAM. An array of memory cells capable of storing at least a megabit of information, each memory cell including a memory plug that includes a memory element that switches from a first resistance state to a second resistance state upon application of a first write voltage of a first polarity and reversibly switches from the second resistance state to the first resistance state upon application of a second write voltage of polarity opposite to the first polarity.
    Type: Grant
    Filed: February 7, 2003
    Date of Patent: July 12, 2005
    Inventors: Darrell Rinerson, Steven W. Longcor, Edmond R. Ward, Steve Kuo-Ren Hsia, Wayne Kinney
  • Patent number: 6909632
    Abstract: Multiple modes of operation in a cross point array. The invention is a cross point array that uses a read voltage across a conductive array line pair during a read mode. The read voltage produces a read current that is indicative of a first program state when the read current is at a first level and indicative of a second program state when the read current is at a second level. The read current is ineffective to produce a change in program state. A first voltage pulse is used during a first write mode if a change from a second program state to a first program state is desired. A second voltage pulse is used during a second write mode if a change from the first program state to the second program state is desired.
    Type: Grant
    Filed: August 17, 2004
    Date of Patent: June 21, 2005
    Inventors: Darrell Rinerson, Christophe J. Chevallier, Steven W. Longcor, Edmond R. Ward, Wayne Kinney, Steve Kuo-Ren Hsia
  • Patent number: 6906939
    Abstract: A re-writable memory with multiple memory layers. Using both terminals of a memory cell in a stacked cross point structure for selection purposes allows multiple layers of conductive lines to be selected as long as there is only one memory cell that has two terminals selected. Sharing logic over multiple layers allows driver sets to be reused.
    Type: Grant
    Filed: July 1, 2003
    Date of Patent: June 14, 2005
    Inventors: Darrell Rinerson, Christophe J. Chevallier, Steven W. Longcor, Wayne Kinney, Edmond R. Ward
  • Patent number: 6870755
    Abstract: A re-writable memory that uses resistive memory cell elements with non-linear IV characteristics is disclosed. Non-linearity is important in certain memory arrays to prevent unselected cells from being disturbed and to reduce the required current. Non-linearity refers to the ability of the element to block the majority of current up to a certain level, but then, once that level is reached, the element allows the majority of the current over and above that level to flow.
    Type: Grant
    Filed: July 30, 2003
    Date of Patent: March 22, 2005
    Inventors: Darrell Rinerson, Christophe J. Chevallier, Steven W. Longcor, Wayne Kinney, Edmond R. Ward, Steve Kuo-Ren Hsia
  • Patent number: 6850429
    Abstract: Providing a cross point, memory array with memory plugs exhibiting a characteristic hysteresis. The memory plugs exhibit a hysteresis that, in the low resistive state, the first write threshold voltage is the point above which any voltages applied across the memory plug have substantially no effect on the resistive state and below which a voltage pulse will alter the resistance of the memory plug. Similarly, in the high resistive state, the second write threshold voltage is the point below which any voltages applied across the memory plug have substantially no effect on the resistive state and above which a voltage pulse will alter the resistance of the memory plug. The read voltages applied to the memory plug are typically above the first write threshold voltage and lower than the second write threshold voltage.
    Type: Grant
    Filed: December 26, 2002
    Date of Patent: February 1, 2005
    Inventors: Darrell Rinerson, Steven W. Longcor, Steve Kuo-Ren Hsia, Wayne Kinney, Edmond R. Ward, Christophe J. Chevallier
  • Patent number: 6834008
    Abstract: Cross point memory array using multiple modes of operation. The invention is a cross point memory array that uses a read mode to determine the resistive state of a memory plug, a first write mode to cause the memory plug to change from a first resistive state to a second resistive state, and a second write mode to cause the memory plug to change from the second resistive state back to the first resistive state.
    Type: Grant
    Filed: December 26, 2002
    Date of Patent: December 21, 2004
    Assignee: Unity Semiconductor Corporation
    Inventors: Darrell Rinerson, Christophe J. Chevallier, Steven W. Longcor, Edmond R. Ward, Wayne Kinney, Steve Kuo-Ren Hsia
  • Patent number: 6831854
    Abstract: Cross point memory array using distinct voltages. The invention is a cross point memory array that applies a first select voltage on one conductive array line, a second select voltage on a second conductive array line, the two conductive array lines uniquely defining a single memory plug. The magnitude of the select voltages depends upon whether a read operation or a write operation is occurring. Additionally, an unselect voltage is applied to the unselected conductive array lines. The unselect voltage can be applied before, after or during the selection process. The unselect voltage is approximately equal to the average of the first select voltage and the second select voltage.
    Type: Grant
    Filed: December 26, 2002
    Date of Patent: December 14, 2004
    Assignee: Unity Semiconductor Corporation
    Inventors: Darrell Rinerson, Steven W. Longcor, Christophe J. Chevallier, Edmond R. Ward, Wayne Kinney, Steve Kuo-Ren Hsia
  • Publication number: 20040228172
    Abstract: A conductive memory stack is provided. The memory stack includes a bottom electrode, a top electrode and a multi-resistive state element. The multi-resistive state element is sandwiched between the electrodes such that the top face of the bottom electrode is in contact with the multi-resistive state element's bottom face and the bottom face of the top electrode is in contact with the multi-resistive state element's top face. The bottom electrode, the top electrode and the multi-resistive state element all have sides that are adjacent to their faces. Furthermore, the sides are at least partially covered by a sidewall layer.
    Type: Application
    Filed: November 11, 2003
    Publication date: November 18, 2004
    Applicant: UNITY SEMICONDUCTOR CORPORATION
    Inventors: Darrell Rinerson, Steve Kuo-Ren Hsia, Steven W. Longcor, Wayne Kinney, Edmond R. Ward, Christophe J. Chevallier
  • Patent number: 6798685
    Abstract: Providing a multi-output multiplexor. The invention is multi-output multiplexor that, depending on the control signals, allows various modulating circuits to pass no voltage, pass some voltage or pass all the voltage on one of the multiplexor's ports. A modulating circuit can be fully turned on, partially turned on, or fully turned off. In a preferred embodiment, a gate circuit is in electrical contact with ground such that when the gate circuit is turned on and its associated modulating curcuit is not passing voltage, the multiplexor output associated with the modulating curcuit goes to ground.
    Type: Grant
    Filed: December 26, 2002
    Date of Patent: September 28, 2004
    Assignee: Unity Semiconductor Corporation
    Inventors: Darrell Rinerson, Christophe J. Chevallier, Steven W. Longcor, Steve Kuo-Ren Hsia
  • Publication number: 20040170040
    Abstract: A re-writable memory that uses resistive memory cell elements with non-linear IV characteristics is disclosed. Non-linearity is important in certain memory arrays to prevent unselected cells from being disturbed and to reduce the required current. Non-linearity refers to the ability of the element to block the majority of current up to a certain level, but then, once that level is reached, the element allows the majority of the current over and above that level to flow.
    Type: Application
    Filed: July 30, 2003
    Publication date: September 2, 2004
    Applicant: UNITY SEMICONDUCTOR CORPORATION
    Inventors: Darrell Rinerson, Christophe J. Chevallier, Steven W. Longcor, Wayne Kinney, Edmond R. Ward, Steve Kuo-Ren Hsia
  • Publication number: 20040159869
    Abstract: A memory array with components that can withstand high temperature fabrication is provided. Some memory materials require high temperature process steps in order to achieve desired properties. During fabrication, a memory material is deposited on structures that may include metal lines and barrier layers. Such structures are then exposed to the high temperature processing steps and should be resistant to such temperatures.
    Type: Application
    Filed: January 26, 2004
    Publication date: August 19, 2004
    Applicant: Unity Semiconductor Corporation
    Inventors: Darrell Rinerson, Steven W. Longcor, Steve Kuo-Ren Hsia, Wayne Kinney, Edmond R. Ward, Christophe J. Chevallier
  • Publication number: 20040159828
    Abstract: A multi-resistive state element that uses a treated interface is provided. A memory plug includes at least two electrodes that sandwich a multi-resistive state element. Using different treatments on both electrode/multi-resistive state element interfaces improves the memory properties of the entire memory device.
    Type: Application
    Filed: September 19, 2003
    Publication date: August 19, 2004
    Applicant: Unity Semiconductor, Inc.
    Inventors: Darrell Rinerson, Wayne Kinney, John Sanchez, Steven W. Longcor, Steve Kuo-Ren Hsia, Edmond R. Ward, Christophe J. Chevallier
  • Publication number: 20040159868
    Abstract: A multi-resistive state element that uses barrier electrodes is provided. If certain materials are used as electrodes, the electrodes can be used for multiple purposes. Oxides and nitrides are especially well suited for acting as a barrier layer, and possibly even an adhesion layer and a sacrificial layer.
    Type: Application
    Filed: October 8, 2003
    Publication date: August 19, 2004
    Inventors: Darrell Rinerson, Steven W. Longcor, Steve Kuo-Ren Hsia, Wayne Kinney, Edmond R. Ward, Christophe J. Chevallier
  • Publication number: 20040160808
    Abstract: Cross point memory array using distinct voltages. The invention is a cross point memory array that applies a first select voltage on one conductive array line, a second select voltage on a second conductive array line, the two conductive array lines uniquely defining a single memory plug. The magnitude of the select voltages depends upon whether a read operation or a write operation is occurring. Additionally, an unselect voltage is applied to the unselected conductive array lines. The unselect voltage can be applied before, after or during the selection process. The unselect voltage is approximately equal to the average of the first select voltage and the second select voltage.
    Type: Application
    Filed: December 26, 2002
    Publication date: August 19, 2004
    Applicant: Unity Semiconductor Corporation
    Inventors: Darrell Rinerson, Steven W. Longcor, Christophe J. Chevallier, Edmond R. Ward, Wayne Kinney, Steve Kuo-Ren Hsia
  • Publication number: 20040160848
    Abstract: Cross point array with fast access time. A cross point array is driven by drivers on a semiconductor substrate. The drivers for either a single-layer cross point array or for the bottom layer of a stacked cross point array can be positioned to improve access time. Specifically, if the x-direction drivers are positioned in the middle of the x-direction conductive array lines and the y-direction drivers are positioned in the middle of the y-direction conductive array lines, the access time will be improved.
    Type: Application
    Filed: July 1, 2003
    Publication date: August 19, 2004
    Inventors: Darrell Rinerson, Christophe J. Chevallier, Steven W. Longcor, Wayne Kinney, Edmond R. Ward, Steve Kuo-Ren Hsia
  • Publication number: 20040161888
    Abstract: A multi-resistive state material that uses dopants is provided. A multi-resistive state material can be used in a memory cell to store information. However, a multi-resistive state material may not have electrical properties that are appropriate for a memory device. Intentionally doping a multi-resistive state material to modify the electrical properties can, therefore, be desirable.
    Type: Application
    Filed: August 4, 2003
    Publication date: August 19, 2004
    Applicant: UNITY SEMICONDUCTOR CORPORATION
    Inventors: Darrell Rinerson, Wayne Kinney, Christophe J. Chevallier, Steven W. Longcor, Edmond R. Ward, Steve Kuo-Ren Hsia