Patents by Inventor Ravi Keshav Joshi

Ravi Keshav Joshi 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: 20240113026
    Abstract: A silicon carbide device includes a silicon carbide substrate, a contact layer located on the silicon carbide substrate and including nickel and silicon, a barrier layer structure including titanium and tungsten, and a metallization layer comprising copper, wherein the contact layer is located between the silicon carbide substrate and at least a part of the barrier layer structure, wherein the barrier layer structure is located between the silicon carbide substrate and the metallization layer, wherein the metallization layer is configured as a contact pad of the silicon carbide device.
    Type: Application
    Filed: December 1, 2023
    Publication date: April 4, 2024
    Inventors: Edward Fürgut, Ravi Keshav Joshi, Thomas Basler, Martin Gruber, Jochen Hilsenbeck, Wolfgang Scholz
  • Publication number: 20240055257
    Abstract: The disclosure relates to a method for manufacturing a contact on a SiC substrate, wherein the method includes: providing a crystalline SiC substrate; modifying a crystal structure in a surface area of the SiC substrate such that a carbon-enriched SiC portion is generated in the surface area; forming a contact layer on the SiC substrate by depositing a metallic contact material onto the surface area that includes the carbon-enriched SiC portion; and thermal annealing of at least a part of the carbon-enriched SiC portion of the SiC substrate and at least a part of the contact layer, such that a ternary metallic phase portion including at least the metallic contact material, silicon, and carbon is generated. Furthermore, SiC semiconductor devices are described, which include a crystalline SiC substrate and a contact layer including a ternary metallic phase portion directly in contact with the SiC substrate surface.
    Type: Application
    Filed: July 27, 2023
    Publication date: February 15, 2024
    Inventors: Saurabh Roy, Werner Schustereder, Ravi Keshav Joshi, Hans-Joachim Schulze, Daria Krasnozhon
  • Publication number: 20240055256
    Abstract: The disclosure relates to a method for manufacturing a contact on a silicon carbide semiconductor substrate and to a silicon carbide semiconductor device comprising a crystalline silicon carbide semiconductor substrate and a contact layer directly in contact with the silicon carbide semiconductor substrate surface and having, at an interface to the semiconductor substrate, a contact phase portion comprising at least a metal, silicon, and carbon. The method comprises the acts of providing a crystalline silicon carbide semiconductor substrate, depositing a metallic contact material layer onto the crystalline silicon carbide semiconductor substrate, and irradiating at least a part of the silicon carbide semiconductor substrate and at least a part of the metallic contact material layer at their interface with at least one thermal annealing laser beam, thereby generating a contact phase portion at the interface, wherein the contact phase portion comprises at least a metal, silicon, and carbon.
    Type: Application
    Filed: August 7, 2023
    Publication date: February 15, 2024
    Inventors: Ravi Keshav JOSHI, Kristijan Luka MLETSCHNIG, Axel KÖNIG, Gregor LANGER
  • Publication number: 20240030032
    Abstract: The present disclosure generally relates to a method of manufacturing a contact on a silicon carbide semiconductor substrate wherein the method comprises providing a 4H—SiC semiconductor substrate, irradiating a surface area of the 4H—SiC semiconductor substrate with a first thermal annealing laser beam, thereby generating a phase separation of the surface area comprising at least a 3C—SiC layer, and depositing a contact material onto the 3C—SiC layer to form a contact layer on the semiconductor substrate. The disclosure further relates to a silicon carbide semiconductor device with an Ohmic contact comprising a 4H—SiC semiconductor substrate, a 3C—SiC layer, and a contact layer directly in contact with the 3C—SiC layer at the semiconductor surface.
    Type: Application
    Filed: July 21, 2023
    Publication date: January 25, 2024
    Inventors: Saurabh ROY, Ravi Keshav JOSHI, Hans-Joachim SCHULZE, Bernhard GOLLER, Daria KRASNOZHON
  • Patent number: 11881512
    Abstract: A method includes providing a silicon carbide substrate, wherein a gate trench extends from a main surface of the silicon carbide substrate into the silicon carbide substrate and wherein a gate dielectric is formed on at least one sidewall of the gate trench, and forming a gate electrode in the gate trench, the gate electrode including a metal structure and a semiconductor layer between the metal structure and the gate dielectric.
    Type: Grant
    Filed: November 4, 2021
    Date of Patent: January 23, 2024
    Assignee: Infineon Technologies AG
    Inventors: Ralf Siemieniec, Thomas Aichinger, Romain Esteve, Ravi Keshav Joshi, Shiqin Niu
  • Patent number: 11842938
    Abstract: A semiconductor device includes a contact metallization layer that includes aluminum and is arranged on a semiconductor substrate, an inorganic passivation structure arranged on the semiconductor substrate, an organic passivation layer comprising a first part that is arranged on the contact metallization layer, and a second part that is arranged on the inorganic passivation structure, a first layer structure including a first part that is in contact with the contact metallization layer, a second part that is contact with the inorganic passivation structure, and a third part that is disposed on the semiconductor substrate laterally between the inorganic passivation structure and the organic passivation layer.
    Type: Grant
    Filed: November 30, 2021
    Date of Patent: December 12, 2023
    Assignee: Infineon Technologies AG
    Inventors: Jens Peter Konrath, Wolfgang Bergner, Romain Esteve, Richard Gaisberger, Florian Grasse, Jochen Hilsenbeck, Ravi Keshav Joshi, Stefan Kramp, Stefan Krivec, Grzegorz Lupina, Hiroshi Narahashi, Andreas Voerckel, Stefan Woehlert
  • Publication number: 20230253454
    Abstract: A method of manufacturing a semiconductor device includes forming a trench that extends from a first surface into a silicon carbide body. A first doped region and an oppositely doped second doped region are formed in the silicon carbide body. A lower layer structure is formed on a lower sidewall portion of the trench. An upper layer stack is formed on an upper sidewall portion and/or on the first surface. The first doped region and the upper layer stack are in direct contact along the upper sidewall portion and/or on the first surface. The second doped region and the lower layer structure are in direct contact along the lower sidewall portion.
    Type: Application
    Filed: January 23, 2023
    Publication date: August 10, 2023
    Inventors: Ravi Keshav Joshi, Thomas Ralf Siemieniec, Werner Schustereder, Kristijan Luka Mletschnig, Axel König
  • Publication number: 20230238442
    Abstract: A semiconductor device includes a semiconductor substrate and a metal nitride layer above the semiconductor substrate. The metal nitride layer forms at least one interface region with the semiconductor substrate. The at least one interface region includes a first portion of the semiconductor substrate, a first portion of the metal nitride layer, and an interface between the first portion of the semiconductor substrate and the first portion of the metal nitride layer. A concentration of nitrogen content at the first portion of the metal nitride layer is higher than a concentration of nitrogen content at a second portion, of the metal nitride layer, outside the interface region. A distribution of nitrogen content throughout the metal nitride layer may have a maximum concentration at the first portion of the metal nitride layer. Alternatively and/or additionally, a method for producing such a semiconductor device is provided herein.
    Type: Application
    Filed: January 17, 2023
    Publication date: July 27, 2023
    Inventors: Ravi Keshav JOSHI, Romain ESTEVE, Saurabh ROY, Bernhard GOLLER, Werner SCHUSTEREDER, Kristijan Luka MLETSCHNIG
  • Publication number: 20230024105
    Abstract: The present disclosure relates to methods of manufacturing Ohmic contacts on a silicon carbide (SiC) substrate including providing a 4H—SiC or 6H—SiC substrate, implanting dopants into a surface region of the 4H—SiC or 6H—SiC substrate, annealing the implanted surface regions to form a 3C—SiC layer, and depositing a metal layer on the 3C—SiC layer. An implanting sequence of the implantation of dopants includes a plurality of plasma deposition acts with implantation energy levels including at least two different implantation energy levels. The implantation energy levels and one or more implantation doses of the plurality of plasma deposition acts are selected to form a 3C—SiC layer in the surface region of the 4H—SiC or 6H—SiC substrate during the annealing act.
    Type: Application
    Filed: July 20, 2022
    Publication date: January 26, 2023
    Inventors: Werner SCHUSTEREDER, Ravi Keshav JOSHI, Hans-Joachim SCHULZE, Ralf SIEMIENIEC, Axel KOENIG
  • Patent number: 11545545
    Abstract: A semiconductor device includes a source region and a drain region of a first conductivity type, a body region of a second conductivity type between the source region and the drain region, a gate configured to control current through a channel of the body region, a drift zone of the first conductivity type between the body region and the drain region, a superjunction structure formed by a plurality of regions of the second conductivity type laterally spaced apart from one another by intervening regions of the drift zone, and a diffusion barrier structure disposed along sidewalls of the regions of the second conductivity type of the superjunction structure. The diffusion barrier structure includes alternating layers of Si and oxygen-doped Si and a Si capping layer on the alternating layers of Si and oxygen-doped Si.
    Type: Grant
    Filed: July 16, 2020
    Date of Patent: January 3, 2023
    Assignee: Infineon Technologies Austria AG
    Inventors: Martin Poelzl, Robert Haase, Sylvain Leomant, Maximilian Roesch, Ravi Keshav Joshi, Andreas Meiser, Xiaoqiu Huang, Ling Ma
  • Publication number: 20220285149
    Abstract: Described herein are a method and a power semiconductor device produced by the method. The power semiconductor device includes: transistor device structures formed in a semiconductor substrate; a structured metallization layer above the semiconductor substrate; a first passivation over the structured metallization layer; a second passivation on the first passivation; an opening in the first passivation and the second passivation such that a first part of the structured metallization layer has a contact region uncovered by the first passivation and the second passivation and a peripheral region laterally surrounding the contact region and covered by the first passivation and the second passivation; a plating that covers the contact region but not the peripheral region of the first part of the structured metallization layer; and a protective layer separating the peripheral region of the first part of the structured metallization layer from the first passivation.
    Type: Application
    Filed: May 26, 2022
    Publication date: September 8, 2022
    Inventors: Ravi Keshav Joshi, Andreas Behrendt, Richard Gaisberger, Anita Satz, Johanna Schlaminger, Johann Schmid, Mario Stanovnik, Juergen Steinbrenner
  • Publication number: 20220285283
    Abstract: A power semiconductor device includes a semiconductor substrate having a wide bandgap semiconductor material and a first surface, an insulation layer above the first surface of the semiconductor substrate, the insulation layer including at least one opening extending through the insulation layer in a vertical direction, a front metallization above the insulation layer with the insulation layer being interposed between the front metallization and the first surface of the semiconductor substrate, and a metal connection arranged in the opening of the insulation layer and electrically conductively connecting the front metallization with the semiconductor substrate; wherein the front metallization includes at least one layer that is a metal or a metal alloy having a higher melting temperature than an intrinsic temperature of the wide bandgap semiconductor material of the semiconductor substrate.
    Type: Application
    Filed: May 24, 2022
    Publication date: September 8, 2022
    Inventors: Edward Fuergut, Ravi Keshav Joshi, Ralf Siemieniec, Thomas Basler, Martin Gruber, Jochen Hilsenbeck, Dethard Peters, Roland Rupp, Wolfgang Scholz
  • Publication number: 20220262906
    Abstract: A silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET) and a method for forming a SiC MOSFET are disclosed. In an example, the method includes forming a gate dielectric that adjoins a body region arranged in a semiconductor body, and forming a gate electrode on the gate dielectric. Forming the gate electrode includes forming a first electrode layer, implanting work function adjusting atoms into the first electrode layer, and forming a second electrode layer on the first electrode layer.
    Type: Application
    Filed: February 15, 2022
    Publication date: August 18, 2022
    Inventors: Ralf SIEMIENIEC, Thomas AICHINGER, Ravi Keshav JOSHI, Werner SCHUSTEREDER
  • Patent number: 11387095
    Abstract: Described herein is a method and a power semiconductor device produced by the method. The method includes: forming a structured metallization layer above a semiconductor substrate; forming a protective layer on the structured metallization layer; forming a first passivation over the structured metallization layer with the protective layer interposed between the first passivation and the structured metallization layer; structuring the first passivation to expose one or more regions of the protective layer; removing the one or more exposed regions of the protective layer to expose one or more parts of the structured metallization layer; and after structuring the first passivation and removing the one or more exposed regions of the protective layer, forming a second passivation on the first passivation and electroless plating the one or more exposed parts of the structured metallization layer.
    Type: Grant
    Filed: August 21, 2020
    Date of Patent: July 12, 2022
    Assignee: Infineon Technologies Austria AG
    Inventors: Ravi Keshav Joshi, Andreas Behrendt, Richard Gaisberger, Anita Satz, Johanna Schlaminger, Johann Schmid, Mario Stanovnik, Juergen Steinbrenner
  • Patent number: 11367683
    Abstract: A silicon carbide device includes a silicon carbide substrate, a contact layer including nickel, silicon and aluminum, a barrier layer structure including titanium and tungsten, and a metallization layer including copper. The contact layer is located on the silicon carbide substrate. The contact layer is located between the silicon carbide substrate and at least a part of the barrier layer structure. The barrier layer structure is located between the silicon carbide substrate and the metallization layer.
    Type: Grant
    Filed: June 26, 2019
    Date of Patent: June 21, 2022
    Assignee: Infineon Technologies AG
    Inventors: Edward Fuergut, Ravi Keshav Joshi, Ralf Siemieniec, Thomas Basler, Martin Gruber, Jochen Hilsenbeck, Dethard Peters, Roland Rupp, Wolfgang Scholz
  • Publication number: 20220093483
    Abstract: A semiconductor device includes a contact metallization layer that includes aluminum and is arranged on a semiconductor substrate, an inorganic passivation structure arranged on the semiconductor substrate, an organic passivation layer comprising a first part that is arranged on the contact metallization layer, and a second part that is arranged on the inorganic passivation structure, a first layer structure including a first part that is in contact with the contact metallization layer, a second part that is contact with the inorganic passivation structure, and a third part that is disposed on the semiconductor substrate laterally between the inorganic passivation structure and the organic passivation layer.
    Type: Application
    Filed: November 30, 2021
    Publication date: March 24, 2022
    Inventors: Jens Peter Konrath, Wolfgang Bergner, Romain Esteve, Richard Gaisberger, Florian Grasse, Jochen Hilsenbeck, Ravi Keshav Joshi, Stefan Kramp, Stefan Krivec, Grzegorz Lupina, Hiroshi Narahashi, Andreas Voerckel, Stefan Woehlert
  • Publication number: 20220059347
    Abstract: Described herein is a method and a power semiconductor device produced by the method. The method includes: forming a structured metallization layer above a semiconductor substrate; forming a protective layer on the structured metallization layer; forming a first passivation over the structured metallization layer with the protective layer interposed between the first passivation and the structured metallization layer; structuring the first passivation to expose one or more regions of the protective layer; removing the one or more exposed regions of the protective layer to expose one or more parts of the structured metallization layer; and after structuring the first passivation and removing the one or more exposed regions of the protective layer, forming a second passivation on the first passivation and electroless plating the one or more exposed parts of the structured metallization layer.
    Type: Application
    Filed: August 21, 2020
    Publication date: February 24, 2022
    Inventors: Ravi Keshav Joshi, Andreas Behrendt, Richard Gaisberger, Anita Satz, Johanna Schlaminger, Johann Schmid, Mario Stanovnik, Juergen Steinbrenner
  • Publication number: 20220059659
    Abstract: A method includes providing a silicon carbide substrate, wherein a gate trench extends from a main surface of the silicon carbide substrate into the silicon carbide substrate and wherein a gate dielectric is formed on at least one sidewall of the gate trench, and forming a gate electrode in the gate trench, the gate electrode including a metal structure and a semiconductor layer between the metal structure and the gate dielectric.
    Type: Application
    Filed: November 4, 2021
    Publication date: February 24, 2022
    Inventors: Ralf Siemieniec, Thomas Aichinger, Romain Esteve, Ravi Keshav Joshi, Shiqin Niu
  • Patent number: 11217500
    Abstract: A semiconductor device includes a contact metallization layer arranged on a semiconductor substrate, an inorganic passivation structure arranged on the semiconductor substrate, and an organic passivation layer. The organic passivation layer is located between the contact metallization layer and the inorganic passivation structure, and located vertically closer to the semiconductor substrate than a part of the organic passivation layer located on top of the inorganic passivation structure.
    Type: Grant
    Filed: April 9, 2019
    Date of Patent: January 4, 2022
    Assignee: Infineon Technologies AG
    Inventors: Jens Peter Konrath, Wolfgang Bergner, Romain Esteve, Richard Gaisberger, Florian Grasse, Jochen Hilsenbeck, Ravi Keshav Joshi, Stefan Kramp, Stefan Krivec, Grzegorz Lupina, Hiroshi Narahashi, Andreas Voerckel, Stefan Woehlert
  • Patent number: 11195921
    Abstract: A semiconductor device includes a gate electrode and a gate dielectric. The gate electrode extends from a first surface of a silicon carbide body into the silicon carbide body. The gate dielectric is between the gate electrode and the silicon carbide body. The gate electrode includes a metal structure and a semiconductor layer between the metal structure and the gate dielectric.
    Type: Grant
    Filed: May 14, 2019
    Date of Patent: December 7, 2021
    Assignee: Infineon Technologies AG
    Inventors: Ralf Siemieniec, Thomas Aichinger, Romain Esteve, Ravi Keshav Joshi, Shiqin Niu