Patents by Inventor ALOK RANJAN

ALOK RANJAN 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: 11133194
    Abstract: A method of etching a substrate includes generating plasma comprising a first concentration of an etchant and a second concentration of an inhibitor and etching the substrate by exposing an exposed interface between a first material and a second material to the plasma. The first material includes a lower reactivity to both the etchant and the inhibitor than the second material. The first concentration is less than the second concentration. Etching the substrate includes etching the first material and the second material at the exposed interface to form an etched indentation including an enriched region of the second material, forming a passivation layer at the enriched region using the inhibitor, and etching the first material at the etched indentation. The passivation layer reduces an etch rate of the second material to a reduced rate that is less than an etch rate of the first material.
    Type: Grant
    Filed: February 20, 2020
    Date of Patent: September 28, 2021
    Assignee: Tokyo Electron Limited
    Inventors: Sergey Voronin, Christopher Catano, Nicholas Joy, Alok Ranjan, Christopher Talone
  • Publication number: 20210296132
    Abstract: A method for treating a substrate includes receiving the substrate in a vacuum process chamber. The substrate includes a III-V film layer disposed on the substrate. The III-V film layer includes an exposed surface, an interior portion underlying the exposed surface, and one or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge. The method further includes altering the chemical composition of the exposed surface and a fraction of the interior portion of the III-V film layer to form an altered portion of the III-V film layer using a first plasma treatment, removing the altered portion of the III-V film layer using a second plasma treatment, and repeating the altering and removing of the III-V film layer until a predetermined amount of the III-V film layer is removed from the substrate.
    Type: Application
    Filed: June 7, 2021
    Publication date: September 23, 2021
    Inventors: Peter Ventzek, Alok Ranjan
  • Patent number: 11094543
    Abstract: A method for forming a semiconductor device includes depositing a metal resist layer over a layer to be patterned that is formed over a substrate; patterning the metal resist layer using a lithography process to form a patterned metal resist layer and expose portions of the layer to be patterned; selectively depositing a silicon containing layer over the patterned resist layer by exposing the substrate to a gas mixture comprising a silicon precursor, the silicon containing layer being preferentially deposited over a top surface of the metal resist layer; and performing a surface cleaning process by exposing the layer to be patterned and the patterned metal resist layer covered with the silicon containing layer to a plasma process with an etch chemistry comprising a halogen or hydrogen.
    Type: Grant
    Filed: December 4, 2020
    Date of Patent: August 17, 2021
    Assignee: TOKYO ELECTRON LIMITED
    Inventors: Yun Han, Peter Ventzek, Alok Ranjan
  • Publication number: 20210249225
    Abstract: A plasma processing method includes providing a first source power (SP) pulse to an SP coupling element for a first SP pulse duration to generate plasma in a processing chamber, providing a high frequency bias power (HBP) pulse to a substrate holder disposed in the processing chamber for a HBP pulse duration overlapping the first SP pulse duration, and providing a first low frequency bias power (LBP) pulse to the substrate holder for a first LBP pulse duration not overlapping the first SP pulse duration. The HBP pulse includes an HBP pulse frequency that is greater than 800 kHz. The first LBP pulse includes an LBP pulse frequency that is less than about 800 kHz.
    Type: Application
    Filed: February 7, 2020
    Publication date: August 12, 2021
    Inventors: Alok Ranjan, Peter Ventzek, Mitsunori Ohata
  • Patent number: 11079682
    Abstract: Methods are provided herein for patterning extreme ultraviolet (EUV) (or lower wavelength) photoresists, such metal-oxide photoresists. A patterning layer comprising a metal-oxide photoresist is formed on one or more underlying layers provided on a substrate, and portions of the patterning layer not covered by a mask overlying the patterning layer are exposed to EUV or lower wavelengths light. A cyclic dry process is subsequently performed to remove portions of the patterning layer exposed to the EUV or lower wavelength light (i.e., the exposed portions) and develop the metal-oxide photoresist pattern. The cyclic dry process generally includes a plurality of deposition and etch steps, wherein the deposition step selectively deposits a protective layer onto unexposed portions of the patterning layer by exposing the substrate to a first plasma, and the etch step selectively etches the exposed portions of the patterning layer by exposing the substrate to a second plasma.
    Type: Grant
    Filed: November 13, 2020
    Date of Patent: August 3, 2021
    Assignee: Tokyo Electron Limited
    Inventors: Yun Han, Peter Ventzek, Alok Ranjan
  • Publication number: 20210210355
    Abstract: A method of plasma processing includes continuously providing a gas into a processing chamber and AC source power to a source power coupling element for a first duration. The AC source power generates a plasma in the processing chamber. The method further includes, while providing the gas and the AC source power, applying a first negative bias voltage to an electron source electrode for a second duration and removing the first negative bias voltage from the electron source electrode for a third duration to discontinue the generation of the electron beam at the end of the second duration. The first negative bias voltage generates an electron beam directed towards a substrate holder. The method also includes applying a second negative bias voltage to the substrate holder while providing the gas and the AC power. The first duration is equal to the sum of the second duration and the third duration.
    Type: Application
    Filed: January 8, 2020
    Publication date: July 8, 2021
    Inventors: Peter Ventzek, Alok Ranjan
  • Patent number: 11056347
    Abstract: A method for treating a substrate includes receiving a substrate in a vacuum process chamber. The substrate includes a III-V film layer disposed on the substrate. The III-V film layer includes an exposed surface, an interior portion underlying the exposed surface, and one or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge. The method further includes altering the chemical composition of the exposed surface and a fraction of the interior portion of the III-V film layer to form an altered portion of the III-V film layer using a hydrogen-based plasma treatment, removing the altered portion of the III-V film layer using a chlorine-based plasma treatment, and repeating the altering and removing of the III-V film layer until a predetermined amount of the III-V film layer is removed from the substrate.
    Type: Grant
    Filed: April 13, 2020
    Date of Patent: July 6, 2021
    Assignee: TOKYO ELECTRON LIMITED
    Inventors: Peter Ventzek, Alok Ranjan
  • Patent number: 11043362
    Abstract: A plasma processing apparatus includes a processing chamber, a substrate disposed in the processing chamber, and a plurality of electron sources configured to supply electrons to a plasma generated in the processing chamber. Each of the plurality of electron sources includes a first side facing the plasma in the processing chamber. Each of the plurality of electron sources also includes a resonant structure disposed at the first side and configured to be held at a negative direct current bias voltage.
    Type: Grant
    Filed: September 17, 2019
    Date of Patent: June 22, 2021
    Assignee: Tokyo Electron Limited
    Inventors: Peter Ventzek, Barton Lane, Zhiying Chen, Alok Ranjan
  • Patent number: 11037798
    Abstract: Embodiments of the disclosure describe a cyclic etch method for carbon-based films. According to one embodiment, the method includes providing a substrate containing the carbon-based film, exposing the carbon-based film to an oxidizing plasma thereby forming an oxidized layer on the carbon-based film, thereafter, exposing the oxidized layer to a non-oxidizing inert gas plasma thereby removing the oxidized layer and forming a carbonized surface layer on the carbon-based film, and repeating the exposing steps at least once.
    Type: Grant
    Filed: November 8, 2017
    Date of Patent: June 15, 2021
    Assignee: Tokyo Electron Limited
    Inventors: Barton G. Lane, Nasim Eibagi, Alok Ranjan, Peter L. G. Ventzek
  • Publication number: 20210151296
    Abstract: A plasma processing apparatus includes a plasma processing chamber, a coil having an uncoiled length L disposed adjacent to the plasma processing chamber, and a plurality of retractable conductors each configured to make electrical contact with the coil in an extended position. A first tap position is located substantially at a distance L/2 measured from a first end along the coil, a second tap position neighboring the first tap position and located substantially at the distance L/2 measured from the first end along the coil, and a third tap position located substantially at the first end of the coil. A controller is configured to operate the plasma processing apparatus in a first operating mode to sustain an inductively coupled plasma and in a second operating mode to sustain a capacitively coupled plasma using subsets of the retractable conductors in the extended position.
    Type: Application
    Filed: January 29, 2021
    Publication date: May 20, 2021
    Inventors: Peter Ventzek, Alok Ranjan, Mitsunori Ohata, Michael Hummel
  • Publication number: 20210145615
    Abstract: The invention relates to an improved coronary stent delivery system to address bifurcation lesion, a modification (channel) in stent 5 delivery system. The said system comprises steps a) to accommodate an extra PTCA wire between the stent and the underlying balloon with first wire in the main branch (MB) port and the side branch wire in channel provided for it in between stent and underlying balloon; b) load the stent on the MB wire and also pass 10 the SB wire in the channel provided for it so that once stent is inflated in the main branch and the balloon is removed after inflation, the side branch is accessible as there is SB wire is already inside the stent; c) another balloon or stent to be used to open the side branch in case there is serious compromise in flow in 15 side branch or if 2 stents strategy is planned.
    Type: Application
    Filed: June 15, 2018
    Publication date: May 20, 2021
    Inventor: Alok RANJAN
  • Patent number: 10998170
    Abstract: Plasma ion energy distribution for ions having different masses is controlled by controlling the relationship between a base RF frequency and a harmonic RF frequency. By the controlling the RF power frequencies, characteristics of the plasma process may be changed based on ion mass. The ions that dominate etching may be selectively based upon whether an ion is lighter or heavier than other ions. Similarly, atomic layer etch processes may be controlled such that the process may be switched between a layer modification step and a layer etch step though adjustment of the RF frequencies. Such switching is capable of being performed within the same gas phase of the plasma process. The control of the RF power includes controlling the phase difference and/or amplitude ratios between a base RF frequency and a harmonic frequency based upon the detection of one or more electrical characteristics within the plasma apparatus.
    Type: Grant
    Filed: April 8, 2019
    Date of Patent: May 4, 2021
    Assignee: Tokyo Electron Limited
    Inventors: Yusuke Yoshida, Sergey Voronin, Alok Ranjan, David J. Coumou, Scott E. White
  • Patent number: 10998169
    Abstract: A method of plasma processing includes generating a first sequence of source power pulses, generating a second sequence of bias power pulses, combining the bias power pulses of the second sequence with the source power pulses of the first sequence to form a combined sequence of alternating source power pulses and bias power pulses, and, using the combined sequence, generating a plasma comprising ions and processing a substrate by delivering the ions to a major surface of the substrate.
    Type: Grant
    Filed: December 17, 2018
    Date of Patent: May 4, 2021
    Assignee: TOKYO ELECTRON LIMITED
    Inventors: Peter Ventzek, Zhiying Chen, Alok Ranjan
  • Patent number: 10991594
    Abstract: Embodiments provide area-selective etching of silicon nitride for the manufacture of microelectronic workpieces through sequential exposure of silicon nitride layers to hydrogen ions/radicals followed by fluorine ions/radicals using beam delivery techniques such as ion beam and/or neutral beam techniques. The area-selective etch processes are anisotropic when hydrogen ions are used and are isotropic when hydrogen radicals are used. Further, sputtering of material onto a substrate for a microelectronic workpiece is not required for the disclosed embodiments. Further, by using ion beam and/or neutral beam techniques, area-selective etching of silicon nitride is achieved as opposed to the large-area etching provided by prior plasma processing techniques. For certain embodiments, the ion/neutral beam techniques described herein are used to fabricate silicon nitride hard masks without requiring the use of any mask.
    Type: Grant
    Filed: June 20, 2019
    Date of Patent: April 27, 2021
    Assignee: TOKYO ELECTRON LIMITED
    Inventors: Sonam D. Sherpa, Alok Ranjan
  • Patent number: 10971373
    Abstract: Methods and systems for cyclic etching of a patterned layer are described. In an embodiment, a method includes receiving a substrate comprising an underlying layer, a mask layer that exposes portions of an intermediate layer that is disposed between the underlying layer and the mask layer. An embodiment may also include forming a first layer on the mask layer and a second layer on the exposed portions of the intermediate layer, the first layer and the second layer being concurrently formed. Additionally, the method may include removing, concurrently, the first layer and the second layer from the substrate. In such embodiments, the method may include alternating between the forming and the removing until portions of the underlying layer are exposed.
    Type: Grant
    Filed: June 19, 2019
    Date of Patent: April 6, 2021
    Assignee: Tokyo Electron Limited
    Inventors: Alok Ranjan, Vinayak Rastogi
  • Publication number: 20210082668
    Abstract: A plasma processing apparatus includes a processing chamber, a substrate disposed in the processing chamber, and a plurality of electron sources configured to supply electrons to a plasma generated in the processing chamber. Each of the plurality of electron sources includes a first side facing the plasma in the processing chamber. Each of the plurality of electron sources also includes a resonant structure disposed at the first side and configured to be held at a negative direct current bias voltage.
    Type: Application
    Filed: September 17, 2019
    Publication date: March 18, 2021
    Inventors: Peter Ventzek, Barton Lane, Zhiying Chen, Alok Ranjan
  • Patent number: 10937664
    Abstract: Methods and systems for surface modification are described. In an embodiment, a method of etching includes providing a substrate having a device structure, portions of which are identified for modification. Such a method may also include passivating target surfaces of the device structure by exposing the device structure to a gas-phase composition at a processing pressure equal to or greater than 100 mTorr to form a protection layer on the target surfaces. Other embodiments of a method may include providing a substrate having a device structure, portions of which identified for removal. Such methods may further include passivating target surfaces of the device structure by exposing the device structure to a gas-phase composition, wherein the ratio of the radical content to the ion content exceeds 10-to-1.
    Type: Grant
    Filed: September 3, 2019
    Date of Patent: March 2, 2021
    Assignee: TOKYO ELECTRON LIMITED
    Inventors: Cedric Thomas, Andrew Nolan, Alok Ranjan
  • Patent number: 10937662
    Abstract: An isotropic plasma etch process for etching silicon oxide is provided. In an embodiment, a first step, a modification step, includes the use of a fluorocarbon based plasma. This modification step provides for the formation of an interface layer and the deposition of a fluorocarbon film on the surface of the silicon oxide. Then, a second step, a removal step includes the use of an oxygen (O2) based plasma. This removal step removes the fluorocarbon film and the interface layer. To promote isotropic etching, the plasma process is performed with little or no low frequency bias power applied to the system. Thus, ion attraction to the substrate is minimized by providing no low frequency power. Further, relatively high pressures are maintained so as to further promote isotropic behavior.
    Type: Grant
    Filed: May 8, 2019
    Date of Patent: March 2, 2021
    Assignee: TOKYO ELECTRON LIMITED
    Inventors: Sonam D. Sherpa, Alok Ranjan
  • Publication number: 20210050183
    Abstract: A method of plasma processing includes performing a reactive species control phase, performing an ion/radical control phase, and performing a by-product control phase. The reactive species control phase includes pulsing source power to a processing chamber to generate ions and radicals in a plasma. The ion/radical control phase is performed after the reactive species control phase. The ion/radical control phase includes reducing the source power to the processing chamber and pulsing bias power to a substrate in the processing chamber. The by-product control phase is performed after the ion/radical control phase. The by-product control phase includes reducing the source power to the processing chamber relative to the reactive species control phase and reducing the bias power to the substrate relative to the ion/radical control phase.
    Type: Application
    Filed: August 14, 2019
    Publication date: February 18, 2021
    Inventors: Peter Ventzek, Alok Ranjan, Mitsunori Ohata
  • Patent number: 10910196
    Abstract: In one embodiment, a plasma processing system includes a plasma processing chamber, a substrate holder disposed in the plasma processing chamber, a coil disposed over the plasma processing chamber, and a plurality of taps configured to contact the coil at an associated contact region. The plasma processing system is configured to sustain a plasma by selecting a subset of taps from the plurality of taps to apply a power source and a reference potential.
    Type: Grant
    Filed: July 24, 2019
    Date of Patent: February 2, 2021
    Assignee: TOKYO ELECTRON LIMITED
    Inventors: Peter Ventzek, Alok Ranjan, Mitsunori Ohata, Michael Hummel