Patents by Inventor Ranbir Singh

Ranbir Singh 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: 20020149022
    Abstract: Silicon carbide devices and methods of fabricating silicon carbide devices are provided by forming a first p-type silicon carbide epitaxial layer on an n-type silicon carbide substrate. At least one first region of n-type silicon carbide is formed extending through the first p-type silicon carbide epitaxial layer and to the n-type silicon carbide substrate so as to provide at least one channel region in the first p-type silicon carbide epitaxial layer. At least one second region of n-type silicon carbide is also formed adjacent and spaced apart from the first region of n-type silicon carbide. A gate dielectric is formed-over the first region of n-type silicon carbide and at least a portion of the second region of n-type silicon carbide. A gate contact is formed on the gate dielectric. A first contact is also formed so as to contact a portion of the p-type epitaxial layer and the second region of n-type silicon carbide. A second contact is also formed on the substrate.
    Type: Application
    Filed: June 7, 2002
    Publication date: October 17, 2002
    Inventors: Sei-Hyung Ryu, Joseph J. Sumakeris, Anant K. Agarwal, Ranbir Singh
  • Patent number: 6459615
    Abstract: A non-volatile memory device is disclosed which includes an erase device that is shared among an array of memory cells. Each of the memory cells in the array includes a control device coupled to a switch device via a common floating gate. Each of at least a subset of the memory cells further includes a portion of the shared erase device, the portion of the shared erase device associated with a given one of the memory cells being coupled to the switch device of that cell via the floating gate of that cell. The shared erase device is utilizable in performing an erase operation for each of the memory cells associated therewith. Advantageously, the use of the shared erase device substantially reduces the circuit area requirements of the memory array. The invention is particularly well suited for implementation in single-poly flash EEPROM embedded memory devices in integrated circuit applications.
    Type: Grant
    Filed: July 23, 2001
    Date of Patent: October 1, 2002
    Assignee: Agere Systems Guardian Corp.
    Inventors: Richard Joseph McPartland, Ranbir Singh
  • Patent number: 6429041
    Abstract: Silicon carbide devices and methods of fabricating silicon carbide devices are provided by forming a first p-type silicon carbide epitaxial layer on an n-type silicon carbide substrate. At least one first region of n-type silicon carbide is formed extending through the first p-type silicon carbide epitaxial layer and to the n-type silicon carbide substrate so as to provide at least one channel region in the first p-type silicon carbide epitaxial layer. At least one second region of n-type silicon carbide is also formed adjacent and spaced apart from the first region of n-type silicon carbide. A gate dielectric is formed over the first region of n-type silicon carbide and at least a portion of the second region of n-type silicon carbide. A gate contact is formed on the gate dielectric. A first contact is also formed so as to contact a portion of the p-type epitaxial layer and the second region of n-type silicon carbide. A second contact is also formed on the substrate.
    Type: Grant
    Filed: July 13, 2000
    Date of Patent: August 6, 2002
    Assignee: Cree, Inc.
    Inventors: Sei-Hyung Ryu, Joseph J. Sumakeris, Anant K. Agarwal, Ranbir Singh
  • Publication number: 20020086491
    Abstract: The present invention provides a semiconductor device located on a semiconductor substrate having opposite types of first and second transistors formed thereon. The device preferably includes a first gate electrode that includes a first metal gate electrode material having a work function compatible with the first transistor, and a second gate electrode that includes a second metal gate electrode material having a work function compatible with the second transistor and the first metal gate electrode material is also located over the second metal gate electrode material, which forms a gate stack.
    Type: Application
    Filed: October 24, 2001
    Publication date: July 4, 2002
    Applicant: Lucent Technologies Inc.
    Inventors: Isik C. Kizilyalli, Ranbir Singh, Lori Stirling
  • Patent number: 6395610
    Abstract: A bipolar transistor includes an oxide layer having graded portions with greatly reduced stress on a silicon substrate. The method of making the oxide preferably includes growing a first oxide portion by upwardly ramping the silicon substrate to a first temperature lower than a glass transition temperature, and exposing the silicon substrate to an oxidizing ambient at the first temperature and for a first time period. Also, the method includes growing a second oxide portion between the first oxide portion and the silicon substrate by exposing the silicon substrate to an oxidizing ambient at a second temperature higher than the glass transition temperature for a second time period. The second oxide portion may have a thickness in a range of about 2 to 75% of a total thickness of the graded, grown, oxide layer. The step of upwardly ramping preferably includes upwardly ramping the temperature at a relatively high ramping rate to reduce any oxide formed during the upward ramping.
    Type: Grant
    Filed: June 20, 2000
    Date of Patent: May 28, 2002
    Assignee: Lucent Technologies Inc.
    Inventors: Kumar Pradip Roy, Ranbir Singh
  • Patent number: 6383879
    Abstract: The present invention provides a semiconductor device located on a semiconductor substrate having opposite types of first and second transistors formed thereon. The device preferably includes a first gate electrode that includes a first metal gate electrode material having a work function compatible with the first transistor, and a second gate electrode that includes a second metal gate electrode material having a work function compatible with the second transistor and the first metal gate electrode material is also located over the second metal gate electrode material, which forms a gate stack.
    Type: Grant
    Filed: May 17, 2000
    Date of Patent: May 7, 2002
    Assignee: Agere Systems Guardian Corp.
    Inventors: Isik C. Kizilyalli, Ranbir Singh, Lori Stirling
  • Publication number: 20020048893
    Abstract: The present invention provides a semiconductor device located on a semiconductor substrate having opposite types of first and second transistors formed thereon. The device preferably includes a first gate electrode that includes a first metal gate electrode material having a work function compatible with the first transistor, and a second gate electrode that includes a second metal gate electrode material having a work function compatible with the second transistor and the first metal gate electrode material is also located over the second metal gate electrode material, which forms a gate stack.
    Type: Application
    Filed: August 27, 2001
    Publication date: April 25, 2002
    Inventors: Isik C. Kizilyalli, Ranbir Singh, Lori Stirling
  • Publication number: 20020038891
    Abstract: Silicon carbide metal-oxide semiconductor field effect transistors (MOSFETs) and methods of fabricating silicon carbide MOSFETs are provided. The silicon carbide MOSFETs have an n-type silicon carbide drift layer, spaced apart p-type silicon carbide regions in the n-type silicon carbide drift layer and having n-type silicon carbide regions therein, and a nitrided oxide layer. The MOSFETs also have n-type shorting channels extending from respective ones of the n-type silicon carbide regions through the p-type silicon carbide regions to the n-type silicon carbide drift layer. In further embodiments, silicon carbide MOSFETs and methods of fabricating silicon carbide MOSFETs are provided that include a region that is configured to self-deplete the source region, between the n-type silicon carbide regions and the drift layer, adjacent the oxide layer, upon application of a zero gate bias.
    Type: Application
    Filed: July 24, 2001
    Publication date: April 4, 2002
    Inventors: Sei-Hyung Ryu, Anant Agarwal, Mrinal Kanti Das, Lori A. Lipkin, John W. Palmour, Ranbir Singh
  • Publication number: 20020015327
    Abstract: The present invention provides memory circuit including a control input, a switch, and a voltage transfer structure including a linear capacitor that electrically couples the control input to the switch.
    Type: Application
    Filed: September 20, 2001
    Publication date: February 7, 2002
    Applicant: Agere Systems Guardian Corp.
    Inventors: Richard J. McPartland, Ranbir Singh
  • Patent number: 6328832
    Abstract: An apparatus and method utilize a rotatable drum implementing both an attraction mechanism and a cutter mechanism to controllably sever segments of material from a web. The drum is rotated at a rate greater than the rate at which the web of material is advanced so that the attraction mechanism supplies the sole source of tension in the web. Moreover, the cutter mechanism severs segments of material while at least a portion of the web of material engages the outer surface of the drum. In addition, an apparatus and method dynamically control the relative rates of advancement of a web of material and an outer surface of a drum such that a predetermined length of material is advanced forward of a predetermined rotational position of the drum so that the predetermined length of material is severed from the web of material while at least a portion of the web of material engages the outer surface of the drum.
    Type: Grant
    Filed: June 26, 1998
    Date of Patent: December 11, 2001
    Assignee: S-CON, Inc.
    Inventors: Svatoboj Otruba, Ranbir Singh Claire
  • Patent number: 6329675
    Abstract: A method of fabricating a self-aligned bipolar junction transistor in a semiconductor structure having a first layer of silicon carbide generally having a first conductivity type and a second layer of silicon carbide generally having a second conductivity type, opposite to the first conductivity type. The method comprises forming a pillar in the second silicon carbide layer, the pillar having a side wall and defining an adjacent horizontal surface on the second layer, forming a dielectric layer having a predetermined thickness on the second semiconductor layer, including the side wall and the horizontal surface. After formation of the dielectric layer, the dielectric layer on a portion of the horizontal surface adjacent the side wall is anisotropically etched while at least a portion of the dielectric layer remains on the side wall, thereby exposing a portion of the horizontal surface.
    Type: Grant
    Filed: February 19, 2001
    Date of Patent: December 11, 2001
    Assignee: Cree, Inc.
    Inventors: Ranbir Singh, Anant K. Agarwal, Sei-Hyung Ryu
  • Patent number: 6324095
    Abstract: The present invention provides memory circuit including a control input, a switch, and a voltage transfer structure including a linear capacitor that electrically couples the control input to the switch.
    Type: Grant
    Filed: May 9, 2000
    Date of Patent: November 27, 2001
    Assignee: Agere Systems Guardian Corp.
    Inventors: Richard J. McPartland, Ranbir Singh
  • Patent number: 6313500
    Abstract: A split gate memory cell is described which is fabricated from two-polysilicon layers and comprises a silicon substrate having a source and a drain electrode and a storage node, a tunnel oxide on the substrate, a first control gate electrode and a floating gate electrode spaced from each other and fabricated from the same polysilicon layer and a second control gate electrode of a second poly material formed between and over the first control gate and floating gate and isolated therefrom by a dielectric layer therebetween.
    Type: Grant
    Filed: December 14, 1999
    Date of Patent: November 6, 2001
    Assignee: Agere Systems Guardian Corp.
    Inventors: Patrick J. Kelley, Chung Wai Leung, Ranbir Singh
  • Patent number: 6303475
    Abstract: Silicon carbide power devices are fabricated by masking the surface of a silicon carbide substrate to define an opening at the substrate, implanting p-type dopants into the silicon carbide substrate through the opening at implant energy and dosage that form a deep p-type implant, and implanting n-type dopants into the silicon carbide substrate through the opening at implant energy and dosage that form a shallow n-type implant relative to the deep p-type implant. The deep p-type implant and the shallow n-type implant are annealed at less than 1650° C., but preferably more than about 1500°. The annealing preferably takes place for between about five minutes and about thirty minutes. Ramp-up time from room temperature to the anneal temperature is also controlled to be less than about one hundred minutes but more than about thirty minutes. Ramp-down time after annealing is also controlled by decreasing the temperature from the annealing temperature to below about 1500° C.
    Type: Grant
    Filed: November 30, 1999
    Date of Patent: October 16, 2001
    Assignee: Cree, Inc.
    Inventors: Alexander Suvorov, John W. Palmour, Ranbir Singh
  • Patent number: 6284598
    Abstract: A method of forming round corners for a gate oxide between a floating gate and a control gate of a memory cell comprises the steps of forming the floating gate over a tunnel oxide; forming a mask over the floating gate; forming rounded end caps adjacent distal ends of the mask; transferring the rounding of the end caps to top corners of the floating gate; forming the gate oxide over the floating gate; and, forming the control gate over the gate oxide. A memory cell having a rounded corner interface between the floating gate and control gate is also provided.
    Type: Grant
    Filed: November 23, 1999
    Date of Patent: September 4, 2001
    Assignee: Agere Systems Guardian Corp.
    Inventors: Patrick J. Kelley, Ranbir Singh, Larry B. Fritzinger, Cynthia C. Lee, John Simon Molloy
  • Publication number: 20010017181
    Abstract: An apparatus and method utilize a rotatable drum implementing both an attraction mechanism and a cutter mechanism to controllably sever segments of material from a web. The drum is rotated at a rate greater than the rate at which the web of material is advanced so that the attraction mechanism supplies the sole source of tension in the web. Moreover, the cutter mechanism severs segments of material while at least a portion of the web of material engages the outer surface of the drum. In addition, an apparatus and method dynamically control the relative rates of advancement of a web of material and an outer surface of a drum such that a predetermined length of material is advanced forward of a predetermined rotational position of the drum so that the predetermined length of material is severed from the web of material while at least a portion of the web of material engages the outer surface of the drum.
    Type: Application
    Filed: May 2, 2001
    Publication date: August 30, 2001
    Applicant: S-CON, INC.
    Inventors: Svatoboj Otruba, Ranbir Singh Claire
  • Patent number: 6281521
    Abstract: Silicon carbide channel semiconductor devices are provided which eliminate the insulator of the gate by utilizing a semiconductor gate layer and buried base regions to create a “pinched off” gate region when no bias is applied to the gate. In particular embodiments of the present invention, the semiconductor devices include a silicon carbide drift layer of a first conductivity type, the silicon carbide drift layer having a first face and having a channel region therein. A buried base region of a second conductivity type semiconductor material is provided in the silicon carbide drift layer so as to define the channel region. A gate layer of a second conductivity type semiconductor material is formed on the first face of the silicon carbide drift layer adjacent the channel region of the silicon carbide drift layer. A gate contact may also be formed on the gate layer. Both transistors and thyristors may be provided.
    Type: Grant
    Filed: July 9, 1998
    Date of Patent: August 28, 2001
    Assignee: Cree Research Inc.
    Inventor: Ranbir Singh
  • Publication number: 20010011729
    Abstract: A method of fabricating a self-aligned bipolar junction transistor in a semiconductor structure having a first layer of silicon carbide generally having a first conductivity type and a second layer of silicon carbide generally having a second conductivity type, opposite to the first conductivity type. The method comprises forming a pillar in the second silicon carbide layer, the pillar having a side wall and defining an adjacent horizontal surface on the second layer, forming a dielectric layer having a predetermined thickness on the second semiconductor layer, including the side wall and the horizontal surface. After formation of the dielectric layer, the dielectric layer on a portion of the horizontal surface adjacent the side wall is anisotropically etched while at least a portion of the dielectric layer remains on the side wall, thereby exposing a portion of the horizontal surface.
    Type: Application
    Filed: February 19, 2001
    Publication date: August 9, 2001
    Inventors: Ranbir Singh, Anant K. Agarwal, Sei-Hyung Ryu
  • Patent number: 6252270
    Abstract: A programmable semiconductor device and a method of manufacturing the same. The device includes: (1) a substrate composed at least in part of silicon, (2) a dielectric layer located over the substrate and (3) a control gate located over the dielectric layer wherein the dielectric layer contains a substantial concentration of an isotope of hydrogen.
    Type: Grant
    Filed: April 28, 1997
    Date of Patent: June 26, 2001
    Assignee: Agere Systems Guardian Corp.
    Inventors: Richard W. Gregor, Isik C. Kizilyalli, Ranbir Singh
  • Patent number: 6222764
    Abstract: An electrically erasable memory device includes a substrate and a plurality of single poly layer memory cells in the substrate. Each single poly layer memory cell includes a first MOS transistor in a first region in the substrate and spaced apart source and drain regions. Each single poly layer memory cell further includes a capacitor having a first electrode overlying a second region in the substrate and an insulating layer therebetween, and a third region in the second region defining a second electrode. An erasing circuit selectively erases the single poly layer memory cell by supplying a first voltage reference of a first polarity to the spaced apart source and drain regions, a second voltage reference of a second polarity to the first region, and a third voltage reference of the second polarity to the second electrode of the capacitor.
    Type: Grant
    Filed: December 13, 1999
    Date of Patent: April 24, 2001
    Assignee: Agere Systems Guardian Corp.
    Inventors: Patrick J. Kelley, Chung Wai Leung, Ranbir Singh