Patents by Inventor Rajesh Prasad

Rajesh Prasad 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: 10804156
    Abstract: A method of forming a three-dimensional transistor device. The method may include providing a transistor structure, where the transistor structure includes a fin assembly, a gate assembly, the gate assembly disposed over the fin assembly and comprising a plurality of gates, a liner layer, disposed over the plurality of gates, and an isolation layer, disposed subjacent the liner layer. The method may also include directing first angled ions at the transistor device, wherein a first altered liner layer is created in the liner layer, wherein, in the presence of a liner-removal etchant, the liner layer exhibits a first etch rate, the first altered liner layer exhibits a second etch rate, greater than the first etch rate.
    Type: Grant
    Filed: June 22, 2018
    Date of Patent: October 13, 2020
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Min Gyu Sung, Rajesh Prasad
  • Patent number: 10727059
    Abstract: Implementations described herein generally relate to the fabrication of integrated circuits. More particularly, the implementations described herein provide techniques for deposition of amorphous carbon films on a substrate. In one implementation, a method of forming an amorphous carbon film is provided. The method comprises depositing an amorphous carbon film on an underlayer positioned on a susceptor in a first processing region. The method further comprises implanting a dopant or inert species into the amorphous carbon film in a second processing region. The dopant or inert species is selected from carbon, boron, nitrogen, silicon, phosphorous, argon, helium, neon, krypton, xenon or combinations thereof. The method further comprises patterning the doped amorphous carbon film. The method further comprises etching the underlayer.
    Type: Grant
    Filed: November 13, 2018
    Date of Patent: July 28, 2020
    Assignee: APPLIED MATERIALS, INC.
    Inventors: Sarah Bobek, Prashant Kumar Kulshreshtha, Rajesh Prasad, Kwangduk Douglas Lee, Harry Whitesell, Hidetaka Oshio, Dong Hyung Lee, Deven Matthew Raj Mittal
  • Patent number: 10629437
    Abstract: A method may include providing a substrate, comprising a patterning layer. The method may include forming a first pattern of first linear structures in the patterning layer, the first linear structures being elongated along a first direction. The method may include forming a mask over the patterning layer, the mask comprising a second pattern of second linear structures, elongated along a second direction, forming a non-zero angle with respect to the first direction. The method may include selectively removing a portion of the patterning layer while the mask is in place, wherein a first etch pattern is formed in the patterning stack, the first etch pattern comprising a two-dimensional array of cavities. The method may include directionally etching the first etch pattern using an angled ion beam, wherein a second etch pattern is formed, comprising the two-dimensional array of cavities, elongated along the first direction.
    Type: Grant
    Filed: August 30, 2018
    Date of Patent: April 21, 2020
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Sony Varghese, John Hautala, Steven R. Sherman, Rajesh Prasad, Min Gyu Sung
  • Patent number: 10528688
    Abstract: Embodiments include herein are directed towards a method for generating an input/output model from a SPICE (Simulation Program with Integrated Circuit Emphasis) netlist. Embodiments may include receiving, using a processor, a SPICE netlist associated with an electronic design and selecting at least a portion of the SPICE netlist for analysis. Embodiments may further include reading the selected portion of the SPICE netlist and rendering a schematic symbol corresponding to the selected portion of the netlist. Embodiments may also include performing one or more operations associated with the schematic symbol and translating the one or more operations into simulation commands.
    Type: Grant
    Filed: December 18, 2017
    Date of Patent: January 7, 2020
    Assignee: Cadence Design Systems, Inc.
    Inventors: Rameet Pal, Taranjit Singh Kukal, Rajesh Prasad Singh
  • Publication number: 20190393094
    Abstract: A method of forming a three-dimensional transistor device. The method may include providing a transistor structure, where the transistor structure includes a fin assembly, a gate assembly, the gate assembly disposed over the fin assembly and comprising a plurality of gates, a liner layer, disposed over the plurality of gates, and an isolation layer, disposed subjacent the liner layer. The method may also include directing first angled ions at the transistor device, wherein a first altered liner layer is created in the liner layer, wherein, in the presence of a liner-removal etchant, the liner layer exhibits a first etch rate, the first altered liner layer exhibits a second etch rate, greater than the first etch rate.
    Type: Application
    Filed: June 22, 2018
    Publication date: December 26, 2019
    Applicant: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Min Gyu Sung, Rajesh Prasad
  • Patent number: 10515802
    Abstract: A method may include depositing a mask layer on a substrate using physical vapor deposition, wherein an absolute value of a stress in the mask layer has a first value; and directing a dose of ions into the mask layer, wherein the absolute value of the stress in the mask layer has a second value, less than the first value, after the directing the dose.
    Type: Grant
    Filed: July 9, 2018
    Date of Patent: December 24, 2019
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Rajesh Prasad, Tzu-Yu Liu, Edwin Arevalo, Deven Mittal, Somchintana Norasetthekul, Kyuha Shim, Lauren Liaw, Takaski Shimizu, Nobuyuki Sasaki, Ryuichi Muira, Hiro Ito
  • Publication number: 20190348287
    Abstract: A method may include providing a substrate, comprising a patterning layer. The method may include forming a first pattern of first linear structures in the patterning layer, the first linear structures being elongated along a first direction. The method may include forming a mask over the patterning layer, the mask comprising a second pattern of second linear structures, elongated along a second direction, forming a non-zero angle with respect to the first direction. The method may include selectively removing a portion of the patterning layer while the mask is in place, wherein a first etch pattern is formed in the patterning stack, the first etch pattern comprising a two-dimensional array of cavities. The method may include directionally etching the first etch pattern using an angled ion beam, wherein a second etch pattern is formed, comprising the two-dimensional array of cavities, elongated along the first direction.
    Type: Application
    Filed: August 30, 2018
    Publication date: November 14, 2019
    Applicant: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Sony Varghese, John Hautala, Steven R. Sherman, Rajesh Prasad, Min Gyu Sung
  • Publication number: 20190326116
    Abstract: A method may include depositing a mask layer on a substrate using physical vapor deposition, wherein an absolute value of a stress in the mask layer has a first value; and directing a dose of ions into the mask layer, wherein the absolute value of the stress in the mask layer has a second value, less than the first value, after the directing the dose.
    Type: Application
    Filed: July 9, 2018
    Publication date: October 24, 2019
    Applicant: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Rajesh Prasad, Tzu-Yu Liu, Edwin Arevalo, Deven Mittal, Somchintana Norasetthekul, Kyuha Shim, Lauren Liaw, Takaski Shimizu, Nobuyuki Sasaki, Ryuichi Muira, Hiro Ito
  • Publication number: 20190304783
    Abstract: A method may include depositing a carbon layer on a substrate using physical vapor deposition, wherein the carbon layer exhibits compressive stress, and is characterized by a first stress value; and directing a dose of low-mass species into the carbon layer, wherein, after the directing, the carbon layer exhibits a second stress value, less compressive than the first stress value.
    Type: Application
    Filed: June 4, 2018
    Publication date: October 3, 2019
    Applicant: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Rajesh Prasad, Tzu-Yu Liu, Kyu-HA Shim, Tom Ho Wing Yu, Zhong Qiang Hua, Adolph Miller Allen, Viabhav Soni, Ravi Rajagopalan, Nobuyuki Sasaki
  • Patent number: 10403738
    Abstract: Methods for forming three-dimensional transistor devices. In one embodiment a method of forming a three-dimensional transistor device may include providing a substrate comprising a semiconductor device structure, the semiconductor device structure comprising a nanowire stack, a gate stack disposed above the nanowire stack, and an inner spacer layer, disposed over the gate stack and the nanowire stack. The method may further include directing ions at the semiconductor device structure, wherein an altered layer is formed in a first part of the inner spacer layer, and an unaltered portion of the inner spacer layer remains, subjacent to the altered layer.
    Type: Grant
    Filed: July 20, 2018
    Date of Patent: September 3, 2019
    Assignee: VARIAN SEMICONDUCTOR EQUIPMENT ASSOCIATES, INC.
    Inventors: Min Gyu Sung, Rajesh Prasad, John Hautala, Sony Varghese
  • Patent number: 10354875
    Abstract: A method may include forming a sacrificial mask on a device structure, the sacrificial mask comprising a carbon-based material. The method may further include etching memory structures in exposed regions of the sacrificial mask, implanting an etch-enhancing species into the sacrificial mask, and performing a wet etch to selectively remove the sacrificial mask at etch temperature, less than 350° C.
    Type: Grant
    Filed: April 6, 2018
    Date of Patent: July 16, 2019
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Rajesh Prasad, Ning Zhan, Tzu-Yu Liu, James Cournoyer, Kyu-Ha Shim, Kwangduk Lee, John Lee Klocke, Eric J. Bergman, Terrance Lee, Harry S. Whitesell
  • Publication number: 20190214255
    Abstract: A method may include forming a sacrificial mask on a device structure, the sacrificial mask comprising a carbon-based material. The method may further include etching memory structures in exposed regions of the sacrificial mask, implanting an etch-enhancing species into the sacrificial mask, and performing a wet etch to selectively remove the sacrificial mask at etch temperature, less than 350° C.
    Type: Application
    Filed: April 6, 2018
    Publication date: July 11, 2019
    Applicant: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Rajesh Prasad, Ning Zhan, Tzu-Yu Liu, James Cournoyer, Kyu-Ha Shim, Kwangduk Lee, John Lee Klocke, Eric J. Bergman, Terrance Lee, Harry S. Whitesell
  • Patent number: 10332748
    Abstract: As etching processes become more aggressive, increased etch resistivity of the hard mask is desirable. Methods of modulating the etch rate of the mask and optionally the underlying material are disclosed. An etch rate modifying species is implanted into the hard mask after the mask etching process is completed. This etch rate modifying species increases the difference between the etch rate of the mask and the etch rate of the underlying material to help preserve the integrity of the mask during a subsequent etching process. In some embodiments, the etch rate of the mask is decreased by the etch rate modifying species. In certain embodiments, the etch rate of the underlying material is increased by the etch rate modifying species.
    Type: Grant
    Filed: February 21, 2018
    Date of Patent: June 25, 2019
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Rajesh Prasad, Steven Robert Sherman, Andrew M. Waite, Sungho Jo, Kyu-Ha Shim, Guy Oteri, Somchintana Norasetthekul
  • Publication number: 20190172714
    Abstract: Implementations described herein generally relate to the fabrication of integrated circuits. More particularly, the implementations described herein provide techniques for deposition of amorphous carbon films on a substrate. In one implementation, a method of forming an amorphous carbon film is provided. The method comprises depositing an amorphous carbon film on an underlayer positioned on a susceptor in a first processing region. The method further comprises implanting a dopant or inert species into the amorphous carbon film in a second processing region. The dopant or inert species is selected from carbon, boron, nitrogen, silicon, phosphorous, argon, helium, neon, krypton, xenon or combinations thereof. The method further comprises patterning the doped amorphous carbon film. The method further comprises etching the underlayer.
    Type: Application
    Filed: November 13, 2018
    Publication date: June 6, 2019
    Inventors: Sarah BOBEK, Prashant KUMAR KULSHRESHTHA, Rajesh PRASAD, Kwangduk Douglas LEE, Harry WHITESELL, Hidetaka OSHIO, Dong Hyung LEE, Deven Matthew Raj MITTAL
  • Publication number: 20180182636
    Abstract: As etching processes become more aggressive, increased etch resistivity of the hard mask is desirable. Methods of modulating the etch rate of the mask and optionally the underlying material are disclosed. An etch rate modifying species is implanted into the hard mask after the mask etching process is completed. This etch rate modifying species increases the difference between the etch rate of the mask and the etch rate of the underlying material to help preserve the integrity of the mask during a subsequent etching process. In some embodiments, the etch rate of the mask is decreased by the etch rate modifying species. In certain embodiments, the etch rate of the underlying material is increased by the etch rate modifying species.
    Type: Application
    Filed: February 21, 2018
    Publication date: June 28, 2018
    Inventors: Rajesh Prasad, Steven Robert Sherman, Andrew M. Waite, Sungho Jo, Kyu-Ha Shim, Guy Oteri, Somchintana Norasetthekul
  • Patent number: 9934982
    Abstract: As etching processes become more aggressive, increased etch resistivity of the hard mask is desirable. Methods of modulating the etch rate of the mask and optionally the underlying material are disclosed. An etch rate modifying species is implanted into the hard mask after the mask etching process is completed. This etch rate modifying species increases the difference between the etch rate of the mask and the etch rate of the underlying material to help preserve the integrity of the mask during a subsequent etching process. In some embodiments, the etch rate of the mask is decreased by the etch rate modifying species. In certain embodiments, the etch rate of the underlying material is increased by the etch rate modifying species.
    Type: Grant
    Filed: December 21, 2015
    Date of Patent: April 3, 2018
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Rajesh Prasad, Steven Robert Sherman, Andrew M. Waite, Sungho Jo, Kyu-Ha Shim, Guy Oteri, Somchintana Norasetthekul
  • Publication number: 20170178914
    Abstract: As etching processes become more aggressive, increased etch resistivity of the hard mask is desirable. Methods of modulating the etch rate of the mask and optionally the underlying material are disclosed. An etch rate modifying species is implanted into the hard mask after the mask etching process is completed. This etch rate modifying species increases the difference between the etch rate of the mask and the etch rate of the underlying material to help preserve the integrity of the mask during a subsequent etching process. In some embodiments, the etch rate of the mask is decreased by the etch rate modifying species. In certain embodiments, the etch rate of the underlying material is increased by the etch rate modifying species.
    Type: Application
    Filed: December 21, 2015
    Publication date: June 22, 2017
    Inventors: Rajesh Prasad, Steven Robert Sherman, Andrew M. Waite, Sungho Jo, Kyu-Ha Shim, Guy Oteri, Somchintana Norasetthekul
  • Patent number: 9018064
    Abstract: A method of doping the polycrystalline channel in a vertical FLASH device is disclosed. This method uses a plurality of high energy ion implants to dope the channel at various depths of the channel. In some embodiments, these ion implants are performed at an angle offset from the normal direction, such that the implanted ions pass through at least a portion of the surrounding ONO stack. By passing through the ONO stack, the distribution of ranges reached by each ion may differ from that created by a vertical implant.
    Type: Grant
    Filed: July 10, 2013
    Date of Patent: April 28, 2015
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Andrew M. Waite, Jonathan Gerald England, Rajesh Prasad
  • Publication number: 20150017772
    Abstract: A method of doping the polycrystalline channel in a vertical FLASH device is disclosed. This method uses a plurality of high energy ion implants to dope the channel at various depths of the channel. In some embodiments, these ion implants are performed at an angle offset from the normal direction, such that the implanted ions pass through at least a portion of the surrounding ONO stack. By passing through the ONO stack, the distribution of ranges reached by each ion may differ from that created by a vertical implant.
    Type: Application
    Filed: July 10, 2013
    Publication date: January 15, 2015
    Inventors: Andrew M. Waite, Jonathan Gerald England, Rajesh Prasad
  • Patent number: 8198460
    Abstract: The present invention relates to an improved process for preparation of the non-steroidal aromatase inhibitor drug, Letrozole of formula (I) and its intermediates, 4-[1-(1,2,4-triazolyl)methyl]-benzonitrile of formula (IV) and 4-[1-(1,2,4-triazolyl)methyl]-benzonitrile hydrochloride of formula (VII), all having a purity of ?99%, which is simple, convenient, economical, does not use hazardous chemicals and industrially viable.
    Type: Grant
    Filed: January 16, 2008
    Date of Patent: June 12, 2012
    Assignee: Fresenius Kabi Oncology Ltd.
    Inventors: Vimal Kumar Shrawat, Jai Pal Singh, Rajesh Prasad Nautiyal