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).

  • Patent number: 7235489
    Abstract: The present invention provides an interconnect that can be employed in an integrated circuit. The interconnect includes a metal line located over a substrate, a dielectric layer located over the metal line, and an interconnect located in the dielectric layer, including a landed portion located over the metal line and an unlanded portion located along at least a portion of a lateral edge of the metal line. The unlanded portion is at least partially filled with a polymer, and the landed portion is substantially filled with a conductive material. A method for manufacturing the interconnect is also provided.
    Type: Grant
    Filed: May 21, 2004
    Date of Patent: June 26, 2007
    Assignee: Agere Systems Inc.
    Inventors: Ranbir Singh, Sen Sidhartha, Nace Rossi
  • Publication number: 20070117336
    Abstract: A method of forming a bipolar device includes forming at least one p-type layer of single crystal silicon carbide and at least one n-type layer of single crystal silicon carbide on a substrate. Stacking faults that grow under forward operation of the device are segregated from at least one of the interfaces between the active region and the remainder of the device. The method of forming bipolar devices includes growing at least one of the epitaxial layers to a thickness greater than the minority carrier diffusion length in that layer. The method also increases the doping concentration of epitaxial layers surrounding the drift region to decrease minority carrier lifetimes therein.
    Type: Application
    Filed: November 16, 2006
    Publication date: May 24, 2007
    Applicant: Cree, Inc.
    Inventors: Joseph Sumakeris, Ranbir Singh, Michael Paisley, Stephan Mueller, Hudson Hobgood, Calvin Carter, Albert Burk
  • Patent number: 7205629
    Abstract: A voltage booster transistor with an optimal conducting path formed in widebandgap semiconductors like Silicon Carbide and Diamond, is provided as a power transistor with a voltage rating >200V. Contrary to conventional vertical design of power transistors, a higher, optimum doping for a given thickness supports higher Source/Drain blocking voltage. A topside and backside gate region of the opposite conductivity type than the channel region providing control of source to drain current path through a small gate voltage. The backside gate and the Drain junction are able to support the rated blocking voltage of the device.
    Type: Grant
    Filed: June 3, 2004
    Date of Patent: April 17, 2007
    Assignee: WidebandGap LLC
    Inventor: Ranbir Singh
  • Publication number: 20070066074
    Abstract: A shallow trench isolation structure having a negative taper angle and a method for forming same. A silicon nitride layer formed over a semiconductor substrate is etched according to a plasma etch process to form a first opening therein having sidewalls that present a negative taper angle. The substrate is etched to form a trench therein underlying the first opening. Silicon dioxide fills both the opening and the trench to form the shallow trench isolation structure, with the silicon dioxide in the opening exhibiting a negative taper angle to avoid formation of conductive stringers during subsequent process steps.
    Type: Application
    Filed: September 19, 2005
    Publication date: March 22, 2007
    Inventors: Nace Rossi, Ranbir Singh, Arun Nanda
  • Publication number: 20060286739
    Abstract: A shallow trench isolation structure having a negative taper angle. A graded doped sacrificial layer is formed over a semiconductor substrate and etched to form a first trench therein having trench sidewalls that present a negative taper angle. The substrate is also etched to form a second trench therein overlying the first trench. Silicon dioxide fills both the first and the second trenches to form the shallow trench isolation structure, with the silicon dioxide in the first trench exhibiting a negative taper angle to avoid formation of polysilicon stringers during a gate polysilicon deposition.
    Type: Application
    Filed: June 15, 2005
    Publication date: December 21, 2006
    Inventors: Nace Rossi, Ranbir Singh, Arun Nanda
  • Patent number: 7141486
    Abstract: A shallow trench isolation structure having a negative taper angle. A graded doped sacrificial layer is formed over a semiconductor substrate and etched to form a first trench therein having trench sidewalls that present a negative taper angle. The substrate is also etched to form a second trench therein overlying the first trench. Silicon dioxide fills both the first and the second trenches to form the shallow trench isolation structure, with the silicon dioxide in the first trench exhibiting a negative taper angle to avoid formation of polysilicon stringers during a gate polysilicon deposition.
    Type: Grant
    Filed: June 15, 2005
    Date of Patent: November 28, 2006
    Assignee: Agere Systems Inc.
    Inventors: Nace Rossi, Ranbir Singh, Arun K. Nanda
  • Patent number: 7105875
    Abstract: A lateral power diodes with an optimal drift doping formed in widebandgap semiconductors like Silicon Carbide, Aluminum Nitride and Gallium Nitride and Diamond are provided with a voltage rating greater 200V. Contrary to conventional vertical design of power diodes, a higher, optimum doping for a given thickness is critical in supporting higher anode/cathode blocking voltage, and lower on-resistance than vertical drift region designs. The backside contact and the anode junction must be able to support the rated blocking voltage of the device.
    Type: Grant
    Filed: June 3, 2004
    Date of Patent: September 12, 2006
    Assignee: Wide bandgap, LLC
    Inventor: Ranbir Singh
  • Patent number: 7026669
    Abstract: A lateral channel transistor with an optimal conducting channel formed in widebandgap semiconductors like Silicon Carbide and Diamond is provided. Contrary to conventional vertical design of power transistors, a higher, optimum doping for a given thickness supports higher source/drain blocking voltage. A backside gate is insulated from the channel region using a low doped layer of the opposite conductivity type than the channel region to support the rated blocking voltage of the device.
    Type: Grant
    Filed: June 3, 2004
    Date of Patent: April 11, 2006
    Inventor: Ranbir Singh
  • Publication number: 20060068562
    Abstract: The present invention provides a trench isolation structure, a method for manufacturing a trench isolation structure, and a method for manufacturing an integrated circuit including the trench isolation structure. In one aspect, the method includes forming a hardmask over a substrate, etching a trench in the substrate through the hardmask, forming a liner in the trench, depositing an interfacial layer over the liner within the trench and over the hardmask and filling the trench with a dielectric material.
    Type: Application
    Filed: September 29, 2004
    Publication date: March 30, 2006
    Applicant: Agere Systems Inc.
    Inventors: Arun Nanda, Nace Rossi, Ranbir Singh
  • Patent number: 7019344
    Abstract: A lateral drift vertical metal-insulated field effect transistor (LDVMISFET) with an optimum conducting channel formed in Silicon Carbide, is provided as a power transistor with a voltage rating of greater than 200 V. The lateral drift region achieves a better on-resistance/breakdown voltage trade-off than the conventional vertical drift region design of power MOSFETs. This is achieved by using an optimal doping and thickness for the voltage blocking and current conduction. The drain and backside terminal is able to support at least the rated blocking voltage of the device. A vertical MIS channel may be formed on the favorable 11-20 plane to achieve a higher MIS channel mobility as compared to the conventional 0001 or 000-1 planes resulting in a much lower on-resistance for the same blocking voltage as compared to conventional vertical MOSFET with similar blocking voltage.
    Type: Grant
    Filed: June 3, 2004
    Date of Patent: March 28, 2006
    Inventor: Ranbir Singh
  • Patent number: 7002829
    Abstract: A method and apparatus for opening a fuse formed on a semiconductor substrate. The apparatus comprises a thyristor formed from CMOS device regions and having a one or two control terminals for permitting current to flow through the thyristor into the fuse, for opening the fuse.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: February 21, 2006
    Assignee: Agere Systems Inc.
    Inventors: Ranbir Singh, Richard J. McPartland, Ross A. Kohler
  • Publication number: 20050280114
    Abstract: A lateral power diodes with an optimal drift doping formed in widebandgap semiconductors like Silicon Carbide, Aluminum Nitride and Gallium Nitride and Diamond are provided with a voltage rating greater 200V. Contrary to conventional vertical design of power diodes, a higher, optimum doping for a given thickness is critical in supporting higher anode/cathode blocking voltage, and lower on-resistance than vertical drift region designs. The backside contact and the anode junction must be able to support the rated blocking voltage of the device.
    Type: Application
    Filed: June 3, 2004
    Publication date: December 22, 2005
    Inventor: Ranbir Singh
  • Publication number: 20050269633
    Abstract: A lateral drift vertical metal-insulated field effect transistor (LDVMISFET) with an optimum conducting channel formed in Silicon Carbide, is provided as a power transistor with a voltage rating of greater than 200V. The lateral drift region achieves a better on-resistance/breakdown voltage trade-off than the conventional vertical drift region design of power MOSFETs. This is achieved by using an optimal doping and thickness for the voltage blocking and current conduction. The drain and backside terminal is able to support at least the rated blocking voltage of the device. A vertical MIS channel may be formed on the favorable 11-20 plane to achieve a higher MIS channel mobility as compared to the conventional 0001 or 000-1 planes resulting in a much lower on-resistance for the same blocking voltage as compared to conventional vertical MOSFET with similar blocking voltage.
    Type: Application
    Filed: June 3, 2004
    Publication date: December 8, 2005
    Inventor: Ranbir Singh
  • Publication number: 20050269661
    Abstract: A lateral channel transistor with an optimal conducting channel formed in widebandgap semiconductors like Silicon Carbide and Diamond is provided. Contrary to conventional vertical design of power transistors, a higher, optimum doping for a given thickness supports higher source/drain blocking voltage. A backside gate is insulated from the channel region using a low doped layer of the opposite conductivity type than the channel region to support the rated blocking voltage of the device.
    Type: Application
    Filed: June 3, 2004
    Publication date: December 8, 2005
    Inventor: Ranbir Singh
  • Publication number: 20050269660
    Abstract: A voltage booster transistor with an optimal conducting path formed in widebandgap semiconductors like Silicon Carbide and Diamond, is provided as a power transistor with a voltage rating >200V. Contrary to conventional vertical design of power transistors, a higher, optimum doping for a given thickness supports higher Source/Drain blocking voltage. A topside and backside gate region of the opposite conductivity type than the channel region providing control of source to drain current path through a small gate voltage. The backside gate and the Drain junction are able to support the rated blocking voltage of the device.
    Type: Application
    Filed: June 3, 2004
    Publication date: December 8, 2005
    Inventor: Ranbir Singh
  • Publication number: 20050260843
    Abstract: The present invention provides an interconnect that can be employed in an integrated circuit. The interconnect includes a metal line located over a substrate, a dielectric layer located over the metal line, and an interconnect located in the dielectric layer, including a landed portion located over the metal line and an unlanded portion located along at least a portion of a lateral edge of the metal line. The unlanded portion is at least partially filled with a polymer, and the landed portion is substantially filled with a conductive material. A method for manufacturing the interconnect is also provided.
    Type: Application
    Filed: May 21, 2004
    Publication date: November 24, 2005
    Applicant: Agere Systems Inc.
    Inventors: Ranbir Singh, Sen Sidhartha, Nace Rossi
  • Patent number: 6956238
    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: Grant
    Filed: July 24, 2001
    Date of Patent: October 18, 2005
    Assignee: Cree, Inc.
    Inventors: Sei-Hyung Ryu, Anant Agarwal, Mrinal Kanti Das, Lori A. Lipkin, John W. Palmour, Ranbir Singh
  • Publication number: 20050118746
    Abstract: A method of forming a bipolar device includes forming at least one p-type layer of single crystal silicon carbide and at least one n-type layer of single crystal silicon carbide on a substrate. Stacking faults that grow under forward operation of the device are segregated from at least one of the interfaces between the active region and the remainder of the device. The method of forming bipolar devices includes growing at least one of the epitaxial layers to a thickness greater than the minority carrier diffusion length in that layer. The method also increases the doping concentration of epitaxial layers surrounding the drift region to decrease minority carrier lifetimes therein.
    Type: Application
    Filed: December 22, 2004
    Publication date: June 2, 2005
    Inventors: Joseph Sumakeris, Ranbir Singh, Michael Paisley, Stephan Mueller, Hudson Hobgood, Calvin Carter, Albert Burk
  • Publication number: 20050116234
    Abstract: A bipolar device has at least one p?type layer of single crystal silicon carbide and at least one n?type layer of single crystal silicon carbide, wherein those portions of those stacking faults that grow under forward operation are segregated from at least one of the interfaces between the active region and the remainder of the device.
    Type: Application
    Filed: December 22, 2004
    Publication date: June 2, 2005
    Inventors: Joseph Sumakeris, Ranbir Singh, Michael Paisley, Stephan Mueller, Hudson Hobgood, Calvin Carter, Albert Burk
  • Publication number: 20050070052
    Abstract: A method and apparatus for opening a fuse formed on a semiconductor substrate. The apparatus comprises a thyristor formed from CMOS device regions and having a one or two control terminals for permitting current to flow through the thyristor into the fuse, for opening the fuse.
    Type: Application
    Filed: September 30, 2003
    Publication date: March 31, 2005
    Inventors: Ranbir Singh, Richard McPartland, Ross Kohler