Patents by Inventor Raj Verma Purakh

Raj Verma Purakh 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: 10797159
    Abstract: Methods of forming an EDNMOS with polysilicon fingers between a gate and a nitride spacer and the resulting devices are provided. Embodiments include forming a polysilicon layer upon a GOX layer over a substrate; forming a gate and plurality of fingers and a gate and plurality of fingers through the polysilicon layer down the GOX layer; forming an oxide layer over the GOX layer and sidewalls of the gates and fingers; forming a nitride layer over the oxide layer; removing portions of the nitride and oxide layers down to the polysilicon and GOX layers to form nitride spacers; and forming S/D regions laterally separated in the substrate, each S/D region adjacent to a nitride spacer.
    Type: Grant
    Filed: April 26, 2019
    Date of Patent: October 6, 2020
    Assignee: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
    Inventors: Lin Wei, Upinder Singh, Raj Verma Purakh
  • Patent number: 10680099
    Abstract: A transistor, such as laterally diffused (LD) transistor, having a band region below a drift well is disclosed. The band region and drift well are oppositely doped. The band region is self-aligned to the drift well. The band region reduces the depth of the drift well. A shallower drift well reduces risk of punch-through, improving reliability. In addition, the shallower drift well reduces the drain to body parasitic capacitance which improves performance.
    Type: Grant
    Filed: February 19, 2018
    Date of Patent: June 9, 2020
    Assignee: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
    Inventors: Liming Li, Shaoqiang Zhang, Ruchil Kumar Jain, Raj Verma Purakh
  • Patent number: 10529738
    Abstract: Integrated circuits and methods for fabricating integrated circuits are provided. An exemplary method for fabricating an integrated circuit includes providing a substrate including a semiconductor layer over an insulator layer. The method includes selectively replacing portions of the semiconductor layer with insulator material to define an isolated semiconductor layer region. Further, the method includes selectively forming a relaxed layer on the isolated semiconductor layer region. Also, the method includes selectively forming a strained layer on the relaxed layer. The method forms a device over the strained layer.
    Type: Grant
    Filed: April 28, 2016
    Date of Patent: January 7, 2020
    Assignee: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
    Inventors: Raj Verma Purakh, Shaoqiang Zhang, Rui Tze Toh
  • Patent number: 10529819
    Abstract: The present invention discloses a Schottky diode. The Schottky diode comprises a substrate having a device well. A drift region is disposed within the device well. A guard ring region is disposed within the device well and adjacent to the drift region. A field isolation region and a dielectric film are disposed on a top substrate surface. The dielectric film is aligned to the field isolation region. A field plate is disposed over the field isolation region and the dielectric film. The field plate completely covers a top surface of the dielectric film and partially overlaps the guard ring region. A conductive contact layer is disposed adjacent to the dielectric film. The conductive contact layer contacts a portion of the device well to define a Schottky diode interface.
    Type: Grant
    Filed: November 4, 2017
    Date of Patent: January 7, 2020
    Assignee: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
    Inventors: Namchil Mun, Shiang Yang Ong, Jeoung Mo Koo, Raj Verma Purakh
  • Patent number: 10522393
    Abstract: Semiconductor devices and methods of forming thereof by post layer transfer fabrication of device isolation structures are described. A substrate with first and second major surfaces is provided. Circuit components may be formed on the first major surface of the substrate and a back-end-of-line (BEOL) dielectric layer is formed over the first major surface of the substrate which covers the circuit components. A single layer transfer is performed to expose the second major surface of the substrate for processing. The second major surface of the semiconductor substrate is processed to thin down the wafer, followed by a wafer thickness uniformity improvement process. One or more device isolation structures are formed through the semiconductor substrate from the second major surface of the semiconductor substrate.
    Type: Grant
    Filed: January 18, 2018
    Date of Patent: December 31, 2019
    Assignee: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
    Inventors: Kouassi Sebastien Kouassi, Raj Verma Purakh
  • Patent number: 10510831
    Abstract: A high voltage transistor with low on resistance is disclosed. The transistor may include at least one cut out region in the drift region under the drain of the transistor. The cut out region is devoid of the drift well which connects the drain to the channel. Cut out regions may be distributed along the width direction of the drain region of the transistor. The transistor may alternatively or further include a vertical polysilicon plate surrounding the device region. The vertical polysilicon plate may be implemented as a deep trench isolation region. The deep trench isolation region includes a deep trench lined with an insulation collar and filled with polysilicon. The vertical polysilicon plate reduces an on resistance to improve device performance.
    Type: Grant
    Filed: February 19, 2018
    Date of Patent: December 17, 2019
    Assignee: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
    Inventors: Namchil Mun, Jeoung Mo Koo, Shiang Yang Ong, Raj Verma Purakh
  • Patent number: 10424655
    Abstract: A method for forming a high voltage device is disclosed. The method comprises providing a substrate defined with a high voltage device region. A device well is formed to encompass the high voltage device region. A drift region is formed within the device well. A body well is formed within the device well adjacent to the drift region. A variable thickness gate dielectric is formed on the substrate. Forming the variable thickness gate dielectric comprises patterned a sacrificial polysilicon layer and oxidizing the patterned sacrificial polysilicon layer to define a thick gate oxide having sloped sidewalls. A gate electrode is formed on the variable thickness gate dielectric, wherein the gate electrode partially overlaps the thick gate oxide. A first and a second source/drain (S/D) region is formed adjacent to first and second sides of the variable thickness gate dielectric.
    Type: Grant
    Filed: December 15, 2017
    Date of Patent: September 24, 2019
    Assignee: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
    Inventors: Ming Li, Jeoung Mo Koo, Raj Verma Purakh
  • Publication number: 20190259829
    Abstract: A high voltage transistor with low on resistance is disclosed. The transistor may include at least one cut out region in the drift region under the drain of the transistor. The cut out region is devoid of the drift well which connects the drain to the channel. Cut out regions may be distributed along the width direction of the drain region of the transistor. The transistor may alternatively or further include a vertical polysilicon plate surrounding the device region. The vertical polysilicon plate may be implemented as a deep trench isolation region. The deep trench isolation region includes a deep trench lined with an insulation collar and filled with polysilicon. The vertical polysilicon plate reduces an on resistance to improve device performance.
    Type: Application
    Filed: February 19, 2018
    Publication date: August 22, 2019
    Inventors: Namchil MUN, Jeoung Mo KIM, Shiang Yang ONG, Raj Verma PURAKH
  • Publication number: 20190259875
    Abstract: A transistor, such as laterally diffused (LD) transistor, having a band region below a drift well is disclosed. The band region and drift well are oppositely doped. The band region is self-aligned to the drift well. The band region reduces the depth of the drift well. A shallower drift well reduces risk of punch-through, improving reliability. In addition, the shallower drift well reduces the drain to body parasitic capacitance which improves performance.
    Type: Application
    Filed: February 19, 2018
    Publication date: August 22, 2019
    Inventors: Liming LI, Shaoqiang ZHANG, Ruchil Kumar JAIN, Raj Verma PURAKH
  • Publication number: 20190252521
    Abstract: Methods of forming an EDNMOS with polysilicon fingers between a gate and a nitride spacer and the resulting devices are provided. Embodiments include forming a polysilicon layer upon a GOX layer over a substrate; forming a gate and plurality of fingers and a gate and plurality of fingers through the polysilicon layer down the GOX layer; forming an oxide layer over the GOX layer and sidewalls of the gates and fingers; forming a nitride layer over the oxide layer; removing portions of the nitride and oxide layers down to the polysilicon and GOX layers to form nitride spacers; and forming S/D regions laterally separated in the substrate, each S/D region adjacent to a nitride spacer.
    Type: Application
    Filed: April 26, 2019
    Publication date: August 15, 2019
    Inventors: Lin WEI, Upinder SINGH, Raj Verma PURAKH
  • Publication number: 20190221472
    Abstract: Semiconductor devices and methods of forming thereof by post layer transfer fabrication of device isolation structures are described. A substrate with first and second major surfaces is provided. Circuit components may be formed on the first major surface of the substrate and a back-end-of-line (BEOL) dielectric layer is formed over the first major surface of the substrate which covers the circuit components. A single layer transfer is performed to expose the second major surface of the substrate for processing. The second major surface of the semiconductor substrate is processed to thin down the wafer, followed by a wafer thickness uniformity improvement process. One or more device isolation structures are formed through the semiconductor substrate from the second major surface of the semiconductor substrate.
    Type: Application
    Filed: January 18, 2018
    Publication date: July 18, 2019
    Inventors: Kouassi Sebastien KOUASSI, Raj Verma PURAKH
  • Patent number: 10347773
    Abstract: Device and method of forming a non-volatile memory (NVM) device are disclosed. The NVM device includes NVM cells disposed on a substrate in a device region. The NVM cell includes a floating gate (FG) with first and second FG sidewalls disposed on the substrate and an intergate dielectric layer disposed over the FG and substrate. Re-entrants are disposed at corners of the intergate dielectric which are filled by dielectric re-entrant spacers. An access gate (AG) with first and second AG sidewalls is disposed on the substrate adjacent to the FG such that the second AG sidewall is adjacent to a first FG sidewall and separated by the intergate dielectric layer and the re-entrant spacers prevent AG from filling the re-entrants. A first source/drain (S/D) region is disposed in the substrate adjacent to the first AG sidewall and a second S/D region is disposed in the substrate adjacent to the second FG sidewall.
    Type: Grant
    Filed: November 8, 2017
    Date of Patent: July 9, 2019
    Assignee: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
    Inventors: Wei Si, Zeng Wang, Jeoung Mo Koo, Raj Verma Purakh
  • Publication number: 20190189779
    Abstract: A method for forming a high voltage device is disclosed. The method comprises providing a substrate defined with a high voltage device region. A device well is formed to encompass the high voltage device region. A drift region is formed within the device well. A body well is formed within the device well adjacent to the drift region. A variable thickness gate dielectric is formed on the substrate. Forming the variable thickness gate dielectric comprises patterned a sacrificial polysilicon layer and oxidizing the patterned sacrificial polysilicon layer to define a thick gate oxide having sloped sidewalls. A gate electrode is formed on the variable thickness gate dielectric, wherein the gate electrode partially overlaps the thick gate oxide. A first and a second source/drain (S/D) region is formed adjacent to first and second sides of the variable thickness gate dielectric.
    Type: Application
    Filed: December 15, 2017
    Publication date: June 20, 2019
    Inventors: Ming LI, Jeoung Mo KOO, Raj Verma PURAKH
  • Patent number: 10319834
    Abstract: Methods of forming an EDNMOS with polysilicon fingers between a gate and a nitride spacer and the resulting devices are provided. Embodiments include forming a polysilicon layer upon a GOX layer over a substrate; forming a gate and plurality of fingers and a gate and plurality of fingers through the polysilicon layer down the GOX layer; forming an oxide layer over the GOX layer and sidewalls of the gates and fingers; forming a nitride layer over the oxide layer; removing portions of the nitride and oxide layers down to the polysilicon and GOX layers to form nitride spacers; and forming S/D regions laterally separated in the substrate, each S/D region adjacent to a nitride spacer.
    Type: Grant
    Filed: July 21, 2017
    Date of Patent: June 11, 2019
    Assignee: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
    Inventors: Lin Wei, Upinder Singh, Raj Verma Purakh
  • Publication number: 20190140099
    Abstract: Device and method of forming a non-volatile memory (NVM) device are disclosed. The NVM device includes NVM cells disposed on a substrate in a device region. The NVM cell includes a floating gate (FG) with first and second FG sidewalls disposed on the substrate and an intergate dielectric layer disposed over the FG and substrate. Re-entrants are disposed at corners of the intergate dielectric which are filled by dielectric re-entrant spacers. An access gate (AG) with first and second AG sidewalls is disposed on the substrate adjacent to the FG such that the second AG sidewall is adjacent to a first FG sidewall and separated by the intergate dielectric layer and the re-entrant spacers prevent AG from filling the re-entrants. A first source/drain (S/D) region is disposed in the substrate adjacent to the first AG sidewall and a second S/D region is disposed in the substrate adjacent to the second FG sidewall.
    Type: Application
    Filed: November 8, 2017
    Publication date: May 9, 2019
    Inventors: Wei SI, Zeng WANG, Jeoung Mo KOO, Raj Verma PURAKH
  • Publication number: 20190140071
    Abstract: The present invention discloses a Schottky diode. The Schottky diode comprises a substrate having a device well. A drift region is disposed within the device well. A guard ring region is disposed within the device well and adjacent to the drift region. A field isolation region and a dielectric film are disposed on a top substrate surface. The dielectric film is aligned to the field isolation region. A field plate is disposed over the field isolation region and the dielectric film. The field plate completely covers a top surface of the dielectric film and partially overlaps the guard ring region. A conductive contact layer is disposed adjacent to the dielectric film. The conductive contact layer contacts a portion of the device well to define a Schottky diode interface.
    Type: Application
    Filed: November 4, 2017
    Publication date: May 9, 2019
    Inventors: Namchil MUN, Shiang Yang ONG, Jeoung Mo KOO, Raj Verma PURAKH
  • Patent number: 10193002
    Abstract: A metal oxide semiconductor varactor includes an active area doped well that is disposed within a semiconductor substrate and a gate structure including a first portion that extends over the active area doped well and a second portion that extends over the semiconductor substrate outside of the active area doped well. The varactor further includes at least one active area contact structure formed in physical and electrical connection with the active area doped well, in a three-sided contact-landing area of the active area doped well. Still further, the varactor includes a gate contact structure that is formed in physical and electrical contact with the gate structure in the second portion of the gate structure such that the gate contact structure overlies the semiconductor substrate outside of the active area doped well.
    Type: Grant
    Filed: September 13, 2016
    Date of Patent: January 29, 2019
    Assignee: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
    Inventors: Kemao Lin, Shaoqiang Zhang, Raj Verma Purakh
  • Publication number: 20190027585
    Abstract: Methods of forming an EDNMOS with polysilicon fingers between a gate and a nitride spacer and the resulting devices are provided. Embodiments include forming a polysilicon layer upon a GOX layer over a substrate; forming a gate and plurality of fingers and a gate and plurality of fingers through the polysilicon layer down the GOX layer; forming an oxide layer over the GOX layer and sidewalls of the gates and fingers; forming a nitride layer over the oxide layer; removing portions of the nitride and oxide layers down to the polysilicon and GOX layers to form nitride spacers; and forming S/D regions laterally separated in the substrate, each S/D region adjacent to a nitride spacer.
    Type: Application
    Filed: July 21, 2017
    Publication date: January 24, 2019
    Inventors: Lin WEI, Upinder SINGH, Raj Verma PURAKH
  • Patent number: 10032766
    Abstract: VDMOS transistors, Bipolar-CMOS-DMOS (BCD) devices including VDMOS transistors, and methods for fabricating integrated circuits with such devices are provided. In an example, a BCD device having a VDMOS transistor includes a buried layer over a substrate and an epitaxial layer over the buried layer and having an upper surface. Deep trench isolation regions extend from the upper surface of the epitaxial layer, into the substrate, and isolate a VDMOS region from a device region. In the VDMOS region, a source region is adjacent the upper surface, a vertical gate structure extends into the epitaxial layer, a body region is located adjacent the vertical gate structure and forms a channel, and a VDMOS conductive structure extends through the epitaxial layer and into the buried layer, which is a drain for the VDMOS transistor. The VDMOS conductive structure is a drain contact to the buried layer.
    Type: Grant
    Filed: September 16, 2016
    Date of Patent: July 24, 2018
    Assignee: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
    Inventors: Ming Li, Namchil Mun, Jeoung Mo Koo, Raj Verma Purakh
  • Patent number: 9960115
    Abstract: Methods of forming a SOI PA and RF switch device having a thin BOX layer in the PA power cell region and a thick metal layer directly under the thin BOX layer and the resulting device are provided. Embodiments include providing a SOI structure having a substrate, BOX, device and metallization layers; bonding a handling layer to the metallization layer; removing the substrate; forming a passivation oxide layer over the BOX; forming first and second trenches through the passivation, BOX, and device layers down to the metallization layer; forming a third trench through the passivation layer and a portion of the BOX above a PA power cell region of the SOI structure, a thin portion of the BOX remaining; forming a first backside contact in the first trench; and forming a second backside contact in the second and third trenches and over a portion of the passivation oxide layer.
    Type: Grant
    Filed: July 3, 2017
    Date of Patent: May 1, 2018
    Assignee: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
    Inventors: Rui Tze Toh, Shyam Parthasarathy, Shaoqiang Zhang, Kouassi Sebastien Kouassi, Bo Yu, Raj Verma Purakh