Patents by Inventor Scott Robins
Scott Robins 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: 7183591Abstract: A semiconductor device includes a thyristor body having at least one region in a substrate. According to an example embodiment of the present invention, a trench is in a substrate and adjacent to a thyristor body region in the substrate. The trench is lined with an insulative material and further includes conductive material that is insulated from the thyristor body region in the substrate by the liner material. A conductive thyristor control port is located in the trench and adapted for capacitively coupling to the thyristor body region in the substrate and to control current in the thyristor body by causing an outflow of minority carriers in the thyristor. With this approach, conductive material can be used to fill a portion of the trench while using the trench portion including the conductive material to electrically isolate a portion of the thyristor body in the substrate.Type: GrantFiled: September 29, 2005Date of Patent: February 27, 2007Assignee: T-RAM Semiconductor, Inc.Inventors: Andrew Horch, Scott Robins
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Patent number: 7157342Abstract: A thyristor-based memory device may comprise a commonly-implanted base region, in which a common emitter region may be implanted for the left and the right thyristors in a mirror-image pair. The implanting of the base region may include directing the dopant toward a semiconductor material through a window defined by sidewalls formed in a conditioned masking material over the semiconductor material. The resulting base and emitter regions may be substantially symmetrical about a central boundary plane. In relation to the symmetry, one thyristor may be operable with a minimum holding current within about 10 percent of that for the other thyristor in the mirror-image pair.Type: GrantFiled: December 29, 2004Date of Patent: January 2, 2007Assignee: T-RAM Semiconductor, IncInventors: Marc Tarabbia, Scott Robins
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Patent number: 7135745Abstract: A semiconductor device having a thyristor-based device and a pass device exhibits characteristics that may include, for example, resistance to short channel effects that occur when conventional MOSFET devices are scaled smaller in connection with advancing technology. According to an example embodiment of the present invention, the semiconductor device includes a pass device having a channel in a fin portion over a semiconductor substrate, and a thyristor device coupled to the pass device. The fin has a top portion and a side portion and extends over the semiconductor substrate. The pass device includes source/drain regions separated by the channel and a gate facing and capacitively coupled to the side portion of the fin that includes the channel. The thyristor device includes anode and cathode end portions, each end portion having base and emitter regions, where one of the emitter regions is coupled to one of the source/drain regions of the pass device.Type: GrantFiled: September 9, 2002Date of Patent: November 14, 2006Assignee: T-Ram, Inc.Inventors: Andrew Horch, Scott Robins
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Patent number: 7125753Abstract: A semiconductor memory device having a thyristor is manufactured in a manner that makes possible self-alignment of one or more portions of the thyristor. According to an example embodiment of the present invention, a gate is formed over a first portion of doped substrate. The gate is used to mask a portion of the doped substrate and a second portion of the substrate is doped before or after a spacer is formed. After the second portion of the substrate is doped, the spacer is then formed adjacent to the gate and used to mask the second portion of the substrate while a third portion of the substrate is doped. The gate and spacer are thus used to form self-aligned doped portions of the substrate, wherein the first and second portions form base regions and the third portion form an emitter region of a thyristor.Type: GrantFiled: June 23, 2005Date of Patent: October 24, 2006Assignee: T-RAM Semiconductor, Inc.Inventors: Andrew Horch, Scott Robins, Farid Nemati
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Patent number: 7109532Abstract: A semiconductor device may comprise a partially-depleted SOI MOSFET having a floating body region disposed between a source and drain. The floating body region may be driven to receive injected carriers for adjusting its potential during operation of the MOSFET. In a particular case, the MOSFET may comprise another region of semiconductor material in contiguous relationship with a drain/source region of the MOSFET and on a side thereof opposite to the body region. This additional region may be formed with a conductivity of type opposite the drain/source, and may establish an effective bipolar device per the body, the drain/source and the additional region. The geometries and doping thereof may be designed to establish a transport gain of magnitude sufficient to assist the injection of carriers into the floating body region, yet small enough to guard against inter-latching with the MOSFET.Type: GrantFiled: December 23, 2003Date of Patent: September 19, 2006Inventors: Zachary K. Lee, Farid Nemati, Scott Robins
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Patent number: 7075122Abstract: In a method of fabricating a semiconductor memory device, a thyristor may be formed in a layer of semiconductor material. Carbon may be implanted and annealed in a base-emitter junction region for the thyristor to affect leakage characteristics. The density of the carbon and/or a bombardment energy and/or an anneal therefore may be selected to establish a low-voltage, leakage characteristic for the junction substantially greater than its leakage absent the carbon. In one embodiment, an anneal of the implanted carbon may be performed in common with an activation for other implant regions the semiconductor device.Type: GrantFiled: September 25, 2003Date of Patent: July 11, 2006Assignee: T-Ram Semiconductor, Inc.Inventors: Kevin J. Yang, Farid Nemati, Scott Robins, James D. Plummer, Hyun-Jin Cho
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Patent number: 7064977Abstract: A reference cell produces a reference current that is about half of the current produced by a memory cell. The reference cell is essentially the same as the memory cell with an additional current reduction device that can be a transistor. Adjusting a reference voltage applied to the transistor allows the reference current to be varied. A control circuit to produce the reference voltage includes dedicated memory and reference cells and a feedback circuit that compares the two cells' currents. The feedback circuit applies the reference voltage to the reference cell of the control circuit and adjusts the reference voltage until the current from the reference cell is about half of the current from the memory cell. The reference voltage is then applied to other reference cells in a memory array.Type: GrantFiled: May 20, 2005Date of Patent: June 20, 2006Assignee: T-RAM, Inc.Inventors: Andrew Horch, Tapan Samaddar, Scott Robins
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Patent number: 7053423Abstract: A thyristor-based semiconductor device exhibits a relatively increased base-emitter capacitance. According to an example embodiment of the present invention, a base region and an adjacent emitter region of a thyristor are doped such that the emitter region has a lightly-doped portion having a light dopant concentration, relative to the base region. In one embodiment, the thyristor is implemented in a memory circuit, wherein the emitter region is coupled to a reference voltage line and a control port is arranged for capacitively coupling to the thyristor for controlling current flow therein. In another implementation, the thyristor is formed on a buried insulator layer of a silicon-on-insulator (SOI) structure. With these approaches, current flow in the thyristor, e.g., for data storage therein, can be tightly controlled.Type: GrantFiled: November 5, 2004Date of Patent: May 30, 2006Assignee: T-RAM, Inc.Inventors: Farid Nemati, Scott Robins, Andrew Horch
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Patent number: 7054191Abstract: A first and a second set of memory cells are connected to the same first word line and second word line. At the commencement of data writing, the first word line is set up. The first set of memory cells is read and temporarily stored into a buffer. At about the same time, the bit lines of the second set of memory cells is set up. After completion of reading of the first set of memory cells, the bit lines of this set of memory cells are set up (while the setting up of the bit lines of the second set of memory cells continues). After the bit lines of both sets of memory cells are set up, the second word line is pulsed. At this time, written into both sets of memory cells begins, which comprises data previously read from the first set of memory cells and new data to be written into the second set of memory cells. It is found that this method reduces the overall write time.Type: GrantFiled: June 3, 2004Date of Patent: May 30, 2006Assignee: T-Ram, Inc.Inventors: Rajesh Narendra Gupta, Scott Robins
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Patent number: 7049182Abstract: A semiconductor device is formed having a thyristor, a pass device and a conductive shunt that electrically connects an emitter region of the thyristor with a node near an upper surface of the substrate. In one example embodiment of the present invention, the conductive shunt is formed in a trench in a substrate and extending from an upper surface of the substrate to an emitter region of a vertical thyristor, with the emitter region being in the substrate and below the upper surface. In one implementation, the thyristor includes a thyristor body and a control port, with an N+ emitter region of the thyristor body being in the substrate and below and upper surface thereof. A pass device is formed adjacent to the thyristor, and the conductive shunt is formed in a trench extending from the N+ emitter region to a source/drain region of the pass device.Type: GrantFiled: October 9, 2003Date of Patent: May 23, 2006Assignee: T-RAM, Inc.Inventors: Andrew Horch, Scott Robins
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Patent number: 7037763Abstract: In an example gated-thyristor circuit, formation of thyristor body regions involves an angled implant of a thyristor body region, such as a base region, to mitigate capacitive coupling of a gated voltage pulse from the thyristor gate to a body region that is not underlying the thyristor gate. According to a more particular example embodiment, such a thyristor switches between a current-passing mode and a current blocking mode in response to at least one voltage pulse coupling to an underlying thyristor base region. Using a first ion type to provide one polarity, an immediately-adjacent thyristor base region is angle implanted through an emitter body region that is located to other side of the adjacent thyristor base region. The emitter body region is then implanted using ions of another ion type to provide the opposite polarity. This angle implantation permits definition of the adjacent thyristor base region sufficiently distant from (e.g.Type: GrantFiled: December 18, 2003Date of Patent: May 2, 2006Assignee: T-RAM Semiconductor, Inc.Inventors: Farid Nemati, Scott Robins, Andrew E. Horch
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Patent number: 7030425Abstract: A semiconductor device includes a thyristor having at least one body region thereof disposed in a substrate, and a filled trench having a conductive material. According to an example embodiment of the present invention, a conductive material having a narrow upper portion over a relatively wide lower portion is in a filled trench adjacent to at least one thyristor body region in a substrate. In one implementation, a thyristor control port is located over the wide lower portion and adjacent to the narrow upper portion of the conductive shunt and is adapted for capacitively coupling to the thyristor body region in the substrate for controlling current in the thyristor. In another implementation, the conductive material is electrically coupled to a buried emitter region of the thyristor and arranged for shunting current between the buried emitter region and a circuit node near an upper portion of the conductive material.Type: GrantFiled: October 1, 2002Date of Patent: April 18, 2006Assignee: TRAM, Inc.Inventors: Andrew Horch, Scott Robins
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Patent number: 7015077Abstract: A semiconductor device is formed having a thyristor and trench arranged to electrically insulate an emitter region of the thyristor from another circuit structure. In one example embodiment of the present invention, a trench having a bottom portion with two different trench depths is etched in the substrate. A thyristor is formed having a control port in a trench and having an emitter region adjacent to the trench and below an upper surface of the substrate. A deeper portion of the trench electrically insulates the emitter region from the other circuit structure. The control port is capacitively coupled to the thyristor and to the other circuit structure (e.g., in response to at least one edge of a voltage pulse applied thereto). In one implementation, the trench further includes an emitter-access connector extending from the emitter region to an upper surface of the substrate.Type: GrantFiled: October 21, 2004Date of Patent: March 21, 2006Assignee: T-RAM, Inc.Inventors: Andrew Horch, Scott Robins
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Patent number: 6998652Abstract: A semiconductor device includes a thyristor body having at least one region in a substrate. According to an example embodiment of the present invention, a trench is in a substrate and adjacent to a thyristor body region in the substrate. The trench is lined with an insulative material and further includes conductive material that is insulated from the thyristor body region in the substrate by the liner material. A conductive thyristor control port is located in the trench and adapted for capacitively coupling to the thyristor body region in the substrate and to control current in the thyristor body by causing an outflow of minority carriers in the thyristor. With this approach, conductive material can be used to fill a portion of the trench while using the trench portion including the conductive material to electrically isolate a portion of the thyristor body in the substrate.Type: GrantFiled: October 1, 2002Date of Patent: February 14, 2006Assignee: T-Ram, Inc.Inventors: Andrew Horch, Scott Robins
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Patent number: 6980457Abstract: A thyristor-based semiconductor device is formed having a thyristor, a pass device and an emitter region buried in a substrate and below at least one other vertically-arranged contiguous region of the thyristor that is at least partially below an upper surface of the substrate. According to an example embodiment of the present invention, a conductor, such as a polysilicon pillar formed in a trench, extends through the substrate and to the buried emitter region of the thyristor. In one implementation, a portion of the conductor includes a reduced-resistance material, such as a salicide, that is adapted to reduce the resistance of an electrical connection made to the buried emitter region via the conductor. This is particularly useful, for example, in connecting the buried emitter region to a power supply at a reduced resistance (e.g., as compared to the resistance that would be exhibited, were the reduced-resistance material not present).Type: GrantFiled: November 6, 2002Date of Patent: December 27, 2005Assignee: T-RAM, Inc.Inventors: Andrew Horch, Scott Robins
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Patent number: 6979602Abstract: A semiconductor device is formed including a substrate having an upper surface, a thyristor region in the substrate and a control port adapted for capacitively coupling to at least a portion of the thyristor region via a dielectric material. According to an example embodiment of the present invention, a trench is formed in the substrate and subsequently filled with materials including dielectric material and a control port. The control port is adapted for capacitively coupling to the thyristor via the dielectric material for controlling current flow in the thyristor (e.g., for causing an outflow of minority carriers from a portion of the thyristor for switching the thyristor from conducting state to a blocking state). A portion of the substrate adjacent to the upper surface is implanted with a species of ions, and the dielectric material via which the control port capacitively couples to the thyristor does not include the species of ions.Type: GrantFiled: December 8, 2003Date of Patent: December 27, 2005Assignee: T-RAM, Inc.Inventors: Andrew Horch, Scott Robins
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Patent number: 6965129Abstract: Switching operations, such as those used in memory devices, are enhanced using a thyristor-based semiconductor device adapted to switch between a blocking state and a conducting state. According to an example embodiment of the present invention, a thyristor-based semiconductor device includes a thyristor having first and second base regions coupled between first and second emitter regions, respectively. A first control port capacitively couples a first signal to the first base region, and a second control port capacitively couples a second signal to the second base region. Each of the first and second signals have a charge that is opposite in polarity, and the opposite polarity signals effect the switching of the thyristor at a lower power, relative to the power that would be required to switch the thyristor having only one control port.Type: GrantFiled: November 6, 2002Date of Patent: November 15, 2005Assignee: T-Ram, Inc.Inventors: Andrew Horch, Scott Robins, Farid Nemati
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Publication number: 20050233506Abstract: A method of fabricating a thyristor-based memory may include forming different opposite conductivity-type regions in silicon for defining a thyristor and an access device in series relationship. An activation anneal may activate dopants previously implanted for the different regions. A damaging implant of germanium or xenon or argon may be directed into select regions of the silicon including at least one p-n junction region for the access device and the thyristor. A re-crystallization anneal may then be performed to re-crystallize at least some of the damaged lattice structure resulting from the damaging implant. The re-crystallization anneal may use a temperature less than that of the previous activation anneal.Type: ApplicationFiled: June 22, 2005Publication date: October 20, 2005Inventors: Andrew Horch, Hyun-Jin Cho, Farid Nemati, Scott Robins, Rajesh Gupta, Kevin Yang
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Patent number: 6944051Abstract: In a thyristor based memory cell, one end of a reversed-biased diode is connected to the cathode of the thyristor. During standby, the second end of the diode is biased at a voltage that is higher than that at the cathode of the thyristor. During restore operation, the second end is pulled down to zero or even a negative value. If the cell is storing a “1,” the voltage at the thyristor cathode can be approximately 0.6 volt at the time of the pull down. The large forward-bias across the diode pulls down the thryistor cathode. This causes the thyristor to be restored. If the cell is storing a “0,” the voltage at the thyristor cathode can be approximately zero volt. The small or zero forward-bias across the diode is unable to disturb the “0” state. As a result, the memory cell is restored to its original state.Type: GrantFiled: October 29, 2003Date of Patent: September 13, 2005Assignee: T-Ram, Inc.Inventors: Zachary K. Lee, Farid Nemati, Scott Robins
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Patent number: 6940772Abstract: A reference cell produces a reference current that is about half of the current produced by a memory cell. The reference cell is essentially the same as the memory cell with an additional current reduction device that can be a transistor. Adjusting a reference voltage applied to the transistor allows the reference current to be varied. A control circuit to produce the reference voltage includes dedicated memory and reference cells and a feedback circuit that compares the two cells' currents. The feedback circuit applies the reference voltage to the reference cell of the control circuit and adjusts the reference voltage until the current from the reference cell is about half of the current from the memory cell. The reference voltage is then applied to other reference cells in a memory array.Type: GrantFiled: March 18, 2002Date of Patent: September 6, 2005Inventors: Andrew Horch, Tapan Samaddar, Scott Robins