Patents by Inventor Lucian Shifren

Lucian Shifren 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).

  • Publication number: 20160336318
    Abstract: A structure and method of fabrication thereof relate to a Deeply Depleted Channel (DDC) design, allowing CMOS based devices to have a reduced ?VT compared to conventional bulk CMOS and can allow the threshold voltage VT of FETs having dopants in the channel region to be set much more precisely. A novel dopant profile indicative of a distinctive notch enables tuning of the VT setting within a precise range. This VT set range may be extended by appropriate selection of metals so that a very wide range of VT settings is accommodated on the die. The DDC design also can have a strong body effect compared to conventional bulk CMOS transistors, which can allow for significant dynamic control of power consumption in DDC transistors. The result is the ability to independently control VT (with a low ?VT) and VDD, so that the body bias can be tuned separately from VT for a given device.
    Type: Application
    Filed: June 24, 2016
    Publication date: November 17, 2016
    Inventors: Reza Arghavani, Pushkar Ranade, Lucian Shifren, Scott E. Thompson, Catherine de Villeneuve
  • Patent number: 9496261
    Abstract: A structure and method of fabrication thereof relate to a Deeply Depleted Channel (DDC) design, allowing CMOS based devices to have a reduced ?VT compared to conventional bulk CMOS and can allow the threshold voltage VT of FETs having dopants in the channel region to be set much more precisely. The DDC design also can have a strong body effect compared to conventional bulk CMOS transistors, which can allow for significant dynamic control of power consumption in DDC transistors. The semiconductor structure includes an analog device and a digital device each having an epitaxial channel layer where a single gate oxidation layer is on the epitaxial channel layer of NMOS and PMOS transistor elements of the digital device and one of a double and triple gate oxidation layer is on the epitaxial channel layer of NMOS and PMOS transistor elements of the analog device.
    Type: Grant
    Filed: August 19, 2013
    Date of Patent: November 15, 2016
    Assignee: Mie Fujitsu Semiconductor Limited
    Inventors: Lucian Shifren, Pushkar Ranade, Scott E. Thompson, Sachrin R. Sonkusale, Weimin Zhang
  • Patent number: 9431068
    Abstract: A dynamic random access memory (DRAM) can include at least one DRAM cell array, comprising a plurality of DRAM cells, each including a storage capacitor and access transistor; a body bias control circuit configured to generate body bias voltage from a bias supply voltage, the body bias voltage being different from power supply voltages of the DRAM; and peripheral circuits formed in the same substrate as the at least one DRAM array, the peripheral circuits comprising deeply depleted channel (DDC) transistors having bodies coupled to receive the body bias voltage, each DDC transistor having a screening region of a first conductivity type formed below a substantially undoped channel region.
    Type: Grant
    Filed: October 31, 2013
    Date of Patent: August 30, 2016
    Assignee: Mie Fujitsu Semiconductor Limited
    Inventors: Lawrence T. Clark, Lucian Shifren, Richard S. Roy
  • Patent number: 9418987
    Abstract: A structure and method of fabrication thereof relate to a Deeply Depleted Channel (DDC) design, allowing CMOS based devices to have a reduced ?VT compared to conventional bulk CMOS and can allow the threshold voltage VT of FETs having dopants in the channel region to be set much more precisely. A novel dopant profile indicative of a distinctive notch enables tuning of the VT setting within a precise range. This VT set range may be extended by appropriate selection of metals so that a very wide range of VT settings is accommodated on the die. The DDC design also can have a strong body effect compared to conventional bulk CMOS transistors, which can allow for significant dynamic control of power consumption in DDC transistors. The result is the ability to independently control VT (with a low ?VT) and VDD, so that the body bias can be tuned separately from VT for a given device.
    Type: Grant
    Filed: June 5, 2014
    Date of Patent: August 16, 2016
    Assignee: Mie Fujitsu Semiconductor Limited
    Inventors: Reza Arghavani, Pushkar Ranade, Lucian Shifren, Scott E. Thompson, Catherine de Villeneuve
  • Patent number: 9406567
    Abstract: Fabrication of a first device on a substrate is performed by exposing a first device region, removing a portion of the substrate to create a trench in the first device region, forming a screen layer with a first dopant concentration in the trench on the substrate, and forming an epitaxial channel on the screen layer having a first thickness. On or more other devices are similarly formed on the substrate independent of each other with epitaxial channels of different thicknesses than the first thickness. Devices with screen layers having the same dopant concentration but with different epitaxial channel thicknesses have different threshold voltages. Thus, a wide variety of threshold voltage devices can be formed on the same substrate. Further threshold voltage setting can be achieved through variations in the dopant concentration of the screen layers.
    Type: Grant
    Filed: February 28, 2012
    Date of Patent: August 2, 2016
    Assignee: Mie Fujitsu Semiconductor Limited
    Inventors: Lucian Shifren, Pushkar Ranade, Thomas Hoffmann, Scott E. Thompson
  • Publication number: 20160211346
    Abstract: Semiconductor structures can be fabricated by implanting a screen layer into a substrate, with the screen layer formed at least in part from a low diffusion dopant species. An epitaxial channel of silicon or silicon germanium is formed above the screen layer, and the same or different dopant species is diffused from the screen layer into the epitaxial channel layer to form a slightly depleted channel (SDC) transistor. Such transistors have inferior threshold voltage matching characteristics compared to deeply depleted channel (DDC) transistors, but can be more easily matched to legacy doped channel transistors in system on a chip (SoC) or multiple transistor semiconductor die.
    Type: Application
    Filed: March 28, 2016
    Publication date: July 21, 2016
    Inventors: Lucian Shifren, Pushkar Ranade, Scott E. Thompson
  • Publication number: 20160181370
    Abstract: An advanced transistor with punch through suppression includes a gate with length Lg, a well doped to have a first concentration of a dopant, and a screening region positioned under the gate and having a second concentration of dopant. The second concentration of dopant may be greater than 5×1018 dopant atoms per cm3. At least one punch through suppression region is disposed under the gate between the screening region and the well. The punch through suppression region has a third concentration of a dopant intermediate between the first concentration and the second concentration of dopant. A bias voltage may be applied to the well region to adjust a threshold voltage of the transistor.
    Type: Application
    Filed: December 22, 2015
    Publication date: June 23, 2016
    Inventors: Lucian Shifren, Pushkar Ranade, Paul E. Gregory, Sachin R. Sonkusale, Weimin Zhang, Scott E. Thompson
  • Patent number: 9368624
    Abstract: A transistor and method of fabrication thereof includes a screening layer formed at least in part in the semiconductor substrate beneath a channel layer and a gate stack, the gate stack including spacer structures on either side of the gate stack. The transistor includes a shallow lightly doped drain region in the channel layer and a deeply lightly doped drain region at the depth relative to the bottom of the screening layer for reducing junction leakage current. A compensation layer may also be included to prevent loss of back gate control.
    Type: Grant
    Filed: July 24, 2015
    Date of Patent: June 14, 2016
    Assignee: Mie Fujitsu Semiconductor Limited
    Inventors: Scott E. Thompson, Lucian Shifren, Pushkar Ranade, Yujie Liu, Sung Hwan Kim, Lingquan Wang, Dalong Zhao, Teymur Bakhishev, Thomas Hoffmann, Sameer Pradhan, Michael Duane
  • Publication number: 20160163823
    Abstract: A semiconductor structure includes first, second, and third transistor elements each having a first screening region concurrently formed therein. A second screening region is formed in the second and third transistor elements such that there is at least one characteristic of the screening region in the second transistor element that is different than the second screening region in the third transistor element. Different characteristics include doping concentration and depth of implant.
    Type: Application
    Filed: February 18, 2016
    Publication date: June 9, 2016
    Inventors: Dalong Zhao, Teymur Bakhishev, Lance Scudder, Paul E. Gregory, Michael Duane, U.C. Sridharan, Pushkar Ranade, Lucian Shifren, Thomas Hoffmann
  • Patent number: 9299698
    Abstract: A semiconductor structure includes first, second, and third transistor elements each having a first screening region concurrently formed therein. A second screening region is formed in the second and third transistor elements such that there is at least one characteristic of the screening region in the second transistor element that is different than the second screening region in the third transistor element. Different characteristics include doping concentration and depth of implant. In addition, a different characteristic may be achieved by concurrently implanting the second screening region in the second and third transistor element followed by implanting an additional dopant into the second screening region of the third transistor element.
    Type: Grant
    Filed: June 25, 2013
    Date of Patent: March 29, 2016
    Assignee: Mie Fujitsu Semiconductor Limited
    Inventors: Dalong Zhao, Teymur Bakhishev, Lance Scudder, Paul E. Gregory, Michael Duane, U. C. Sridharan, Pushkar Ranade, Lucian Shifren, Thomas Hoffmann
  • Publication number: 20160078999
    Abstract: An electrical component is formed with a directed self assembly portion having a random electrical characteristic, such as resistance or capacitance. The random pattern can be produced by using a directed self assembly polymer with guide structures 2 including randomness inducing features. The electrical components with the random electrical characteristics may be used in electrical circuits relying upon random variation in electrical characteristics, such as physically unclonable function circuitry. The electrical components may be resistors and/or capacitors.
    Type: Application
    Filed: September 17, 2014
    Publication date: March 17, 2016
    Inventors: Lucian SHIFREN, Vikas CHANDRA, Mudit BHARGAVA
  • Patent number: 9263523
    Abstract: An advanced transistor with punch through suppression includes a gate with length Lg, a well doped to have a first concentration of a dopant, and a screening region positioned under the gate and having a second concentration of dopant. The second concentration of dopant may be greater than 5×1018 dopant atoms per cm3. At least one punch through suppression region is disposed under the gate between the screening region and the well. The punch through suppression region has a third concentration of a dopant intermediate between the first concentration and the second concentration of dopant. A bias voltage may be applied to the well region to adjust a threshold voltage of the transistor.
    Type: Grant
    Filed: February 24, 2014
    Date of Patent: February 16, 2016
    Assignee: Mie Fujitsu Semiconductor Limited
    Inventors: Lucian Shifren, Pushkar Ranade, Paul E. Gregory, Sachin R. Sonkusale, Weimin Zhang, Scott E. Thompson
  • Patent number: 9224733
    Abstract: A semiconductor structure includes a first PMOS transistor element having a gate region with a first gate metal associated with a PMOS work function and a first NMOS transistor element having a gate region with a second metal associated with a NMOS work function. The first PMOS transistor element and the first NMOS transistor element form a first CMOS device. The semiconductor structure also includes a second PMOS transistor that is formed in part by concurrent deposition with the first NMOS transistor element of the second metal associated with a NMOS work function to form a second CMOS device with different operating characteristics than the first CMOS device.
    Type: Grant
    Filed: October 4, 2013
    Date of Patent: December 29, 2015
    Assignee: Mie Fujitsu Semiconductor Limited
    Inventors: Lucian Shifren, Pushkar Ranade, Sachin R. Sonkusale
  • Publication number: 20150340460
    Abstract: An advanced transistor with threshold voltage set dopant structure includes a gate with length Lg and a well doped to have a first concentration of a dopant. A screening region is positioned between the well and the gate and has a second concentration of dopant greater than 5×1018 dopant atoms per cm3. A threshold voltage set region is formed by placement of a threshold voltage offset plane positioned above the screening region. The threshold voltage set region may be formed by delta doping and have a thickness between Lg/5 and Lg/1 The structure uses minimal or no halo implants to maintain channel dopant concentration at less than 5×1017 dopant atoms per cm3.
    Type: Application
    Filed: July 29, 2015
    Publication date: November 26, 2015
    Inventors: Lucian Shifren, Pushkar Ranade, Lance Scudder
  • Patent number: 9196727
    Abstract: A transistor and method of fabrication thereof includes a screening layer formed at least in part in the semiconductor substrate beneath a channel layer and a gate stack, the gate stack including spacer structures on either side of the gate stack. The transistor includes a shallow lightly doped drain region in the channel layer and a deeply lightly doped drain region at the depth relative to the bottom of the screening layer for reducing junction leakage current. A compensation layer may also be included to prevent loss of back gate control.
    Type: Grant
    Filed: November 6, 2014
    Date of Patent: November 24, 2015
    Assignee: Mie Fujitsu Semiconductor Limited
    Inventors: Scott E. Thompson, Lucian Shifren, Pushkar Ranade, Yujie Liu, Sung Hwan Kim, Lingquan Wang, Dalong Zhao, Teymur Bakhishev, Thomas Hoffmann, Sameer Pradhan, Michael Duane
  • Publication number: 20150333144
    Abstract: A transistor and method of fabrication thereof includes a screening layer formed at least in part in the semiconductor substrate beneath a channel layer and a gate stack, the gate stack including spacer structures on either side of the gate stack. The transistor includes a shallow lightly doped drain region in the channel layer and a deeply lightly doped drain region at the depth relative to the bottom of the screening layer for reducing junction leakage current. A compensation layer may also be included to prevent loss of back gate control.
    Type: Application
    Filed: July 24, 2015
    Publication date: November 19, 2015
    Inventors: Scott E. Thompson, Lucian Shifren, Pushkar Ranade, Yujie Liu, Sung Hwan Kim, Lingquan Wang, Dalong Zhao, Teymur Bakhishev, Thomas Hoffmann, Sameer Pradhan, Michael Duane
  • Patent number: 9111785
    Abstract: A method for fabricating a semiconductor structure with a channel stack includes forming a screening layer under a gate of a PMOS transistor element and a NMOS transistor element, forming a threshold voltage control layer on the screening layer, and forming an epitaxial channel layer on the threshold control layer. At least a portion of the epitaxial channel layers for the PMOS transistor element and the NMOS transistor element are formed as a common blanket layer. The screening layer for the PMOS transistor element may include antimony as a dopant material that may be inserted into the structure prior to or after formation of the epitaxial channel layer.
    Type: Grant
    Filed: July 31, 2013
    Date of Patent: August 18, 2015
    Assignee: Mie Fujitsu Semiconductor Limited
    Inventors: Paul E. Gregory, Pushkar Ranade, Lucian Shifren
  • Patent number: 9105711
    Abstract: A semiconductor structure is formed with a NFET device and a PFET device. The NFET device is formed by masking the PFET device regions of a substrate, forming a screen layer through epitaxial growth and in-situ doping, and forming an undoped channel layer on the screen layer through epitaxial growth. The PFET device is similarly formed by masking the NFET regions of a substrate, forming a screen layer through epitaxial growth and in-situ doping, and forming an undoped channel layer on the screen layer through epitaxial growth. An isolation region is formed between the NFET and the PFET device areas to remove any facets occurring during the separate epitaxial growth phases. By forming the screen layer through in-situ doped epitaxial growth, a reduction in junction leakage is achieved versus forming the screen layer using ion implantation.
    Type: Grant
    Filed: December 19, 2013
    Date of Patent: August 11, 2015
    Assignee: MIE Fujitsu Semiconductor Limited
    Inventors: Lingquan Wang, Teymur Bakhishev, Dalong Zhao, Pushkar Ranade, Sameer Pradhan, Thomas Hoffmann, Lucian Shifren, Lance Scudder
  • Patent number: 9093469
    Abstract: An analog transistor useful for low noise applications or for electrical circuits benefiting from tight control of threshold voltages and electrical characteristics is described. The analog transistor includes a substantially undoped channel positioned under a gate dielectric between a source and a drain with the undoped channel not being subjected to contaminating threshold voltage implants or halo implants. The channel is supported on a screen layer doped to have an average dopant density at least five times as great as the average dopant density of the substantially undoped channel which, in turn, is supported by a doped well having an average dopant density at least twice the average dopant density of the substantially undoped channel.
    Type: Grant
    Filed: May 9, 2014
    Date of Patent: July 28, 2015
    Assignee: Mie Fujitsu Semiconductor Limited
    Inventors: Lucian Shifren, Scott E. Thompson, Paul E. Gregory
  • Patent number: 9041126
    Abstract: A semiconductor transistor structure fabricated on a silicon substrate effective to set a threshold voltage, control short channel effects, and control against excessive junction leakage may include a transistor gate having a source and drain structure. A highly doped screening region lies is embedded a vertical distance down from the surface of the substrate. The highly doped screening region is separated from the surface of the substrate by way of a substantially undoped channel layer which may be epitaxially formed. The source/drain structure may include a source/drain extension region which may be raised above the surface of the substrate. The screening region is preferably positioned to be located at or just below the interface between the source/drain region and source/drain extension portion. The transistor gate may be formed below a surface level of the silicon substrate and either above or below the heavily doped portion of the source/drain structure.
    Type: Grant
    Filed: September 5, 2013
    Date of Patent: May 26, 2015
    Assignee: Mie Fujitsu Semiconductor Limited
    Inventors: Thomas Hoffmann, Lucian Shifren, Scott E. Thompson, Pushkar Ranade, Jing Wang, Paul E. Gregory, Sachin R. Sonkusale, Lance Scudder, Dalong Zhao, Teymur Bakhishev, Yujie Liu, Lingquan Wang, Weimin Zhang, Sameer Pradhan, Michael Duane, Sung Hwan Kim