Patents by Inventor Karl A. Littau

Karl A. Littau 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: 6071572
    Abstract: In a vapor deposition chamber which holds a substrate for processing, a method including the steps of forming a layer of material on the surface of the substrate, wherein the layer of material is made of Ti atoms; remotely activating a source gas containing nitrogen so as to produce activated nitrogen gas species; and while forming the layer of material on the substrate, injecting the activated nitrogen species into the processing chamber to increase the population of activated nitrogen species that is incorporated into the layer of material that is being formed.
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: June 6, 2000
    Assignee: Applied Materials, Inc.
    Inventors: Roderick C. Mosely, Jim Van Gogh, Karl A. Littau
  • Patent number: 6033480
    Abstract: This invention provides a method and apparatus for substantially eliminating deposition on the edge of a wafer supported on a pedestal in a processing chamber. Process gas flow onto the wafer surface is inhibited from reaching the wafer edge and backside, by means of a shadow ring placed over the wafer without touching it. Deposition on the edge and backside of the wafer are therefore substantially eliminated. The shadow ring defines a cavity which circumscribes the wafer edge, into which purge gas is flowed. This purge gas flows out from the cavity through the gap between the shadow ring and the upper surface of the wafer. Alignment pins are placed on the wafer supporting surface of the pedestal. These pins have sloping surfaces and are arranged to guide the wafer to a centered position on the pedestal when the wafer is placed on the pedestal. These pins also serve to align the shadow ring to the pedestal and thence to the wafer.
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: March 7, 2000
    Assignee: Applied Materials, Inc.
    Inventors: Aihua Chen, Karl A. Littau, Dashun S. Zhou
  • Patent number: 5989999
    Abstract: The construction of a film on a wafer, which is placed in a processing chamber, may be carried out through the following steps. A layer (film) of tantalum nitride material is deposited on the wafer. Next, the layer of tantalum nitride material is annealed. The deposition and annealing may both be accomplished in the same chamber, without need for removing the wafer from the chamber until both steps are completed.
    Type: Grant
    Filed: September 26, 1997
    Date of Patent: November 23, 1999
    Assignee: Applied Materials, Inc.
    Inventors: Timothy E. Levine, Ling Chen, Mei Chang, Roderick C. Mosely, Karl A. Littau, Ivo Raaijmakers
  • Patent number: 5888304
    Abstract: This invention provides a method and apparatus for supporting a wafer in a processing chamber, where the wafer is supported and heated from below via a heater pedestal having a diameter larger than that of the wafer. A process fluid flowing downward toward the top of the wafer is inhibited from depositing near the wafer edge by a shadow ring. The shadow ring, which is placed over but does not contact the wafer, physically masks an annular strip of the wafer near its edge. The shadow ring inhibits deposition of process fluides on the wafer in two distinct ways. First, the shadow ring physically obstructs process gas, flowing downward from above the wafer, from depositing on the masked portion of the wafer. Second, the shadow ring is used to direct a flow of a purge gas to inhibit process gas from seeping under the shadow ring and depositing near the wafer edge. A purge gas manifold is defined by a cylindrical annulus located concentrically below the shadow ring and circumscribing the heater pedestal.
    Type: Grant
    Filed: April 2, 1996
    Date of Patent: March 30, 1999
    Assignee: Applied Materials, Inc.
    Inventors: Salvador P. Umotoy, Alan F. Morrison, Karl A. Littau, Richard A. Marsh, Lawrence Chung-Lai Lei, Dale DuBois
  • Patent number: 5882419
    Abstract: An improved deposition chamber deposits useful layers on substrates. The improved chamber includes a substrate edge protection system which, in combination with a purge gas, protects selected portions of the edge and underside of the substrate from the deposition gas while preventing the creation of a masked area on the substrate edge. The substrate is supported on a solid receiving plate, and a positioning assembly aligns the substrate to the receiving plate. In some embodiments, the invention may include a stem interconnected to the substrate, a heat limiting member disposed about the stem, and a shroud extending about the stem.
    Type: Grant
    Filed: September 29, 1997
    Date of Patent: March 16, 1999
    Assignee: Applied Materials, Inc.
    Inventors: Ashok Sinha, Mei Chang, Ilya Perlov, Karl Littau, Alan Morrison, Lawrence Chung-Lai Lei
  • Patent number: 5858464
    Abstract: A method and apparatus for minimizing excess aluminum deposition that can build up inside a substrate processing chamber during an aluminum CVD substrate processing operation. The method of the present invention periodically introduces nitrogen into the processing chamber after aluminum CVD processing of at least a single wafer in order to minimize unwanted aluminum accumulation in various parts of the chamber. According to one embodiment, the present invention provides a method of minimizing excess metal deposition inside a substrate processing chamber after a substrate processing operation. The method includes the steps of introducing a nitrogen-containing passivating gas into a chamber after the substrate processing operation, and maintaining at least a portion of the chamber at a second temperature during the introducing step thereby reducing excess metal build up within the chamber. In preferred embodiments, the method is performed after removal of the substrate from the processing chamber.
    Type: Grant
    Filed: February 13, 1997
    Date of Patent: January 12, 1999
    Assignee: Applied Materials, Inc.
    Inventors: Karl Littau, Dashun S. Zhou, Alfred Mak, Ling Chen
  • Patent number: 5856240
    Abstract: Vacuum CVD chambers are disclosed which provide a more uniformly deposited thin film on a substrate. The chamber susceptor mount for the substrate is heated resistively with a single coil firmly contacting the metal of the susceptor on all sides, providing uniform temperatures across the susceptor mount for a substrate. A purge gas line is connected to openings in the susceptor outside of the periphery of the substrate to prevent edge and backside contamination of the substrate. A vacuum feed line mounts the substrate to the susceptor plate during processing. A refractory purge guide, or a plurality of placement pins, maintain a fixed gap passage for the purge gases to pass alongside the edge of the wafer and into the processing area of the chamber. An exhaust pumping plate improves the uniformity of exhaustion of spent gases from the chamber.
    Type: Grant
    Filed: November 21, 1994
    Date of Patent: January 5, 1999
    Assignee: Applied Materials, Inc.
    Inventors: Ashok Sinha, Mei Chang, Ilya Perlov, Karl A. Littau, Alan F. Morrison, Lawrence Chung-Lai Lei
  • Patent number: 5800686
    Abstract: An improved deposition chamber deposits useful layers on substrates. The improved chamber includes a substrate edge protection system which, in combination with a purge gas, protects selected portions of the edge and underside of the substrate from the deposition gas while preventing the creation of a masked area on the substrate edge. The substrate edge protection system includes a ring, which is received over a substrate received on the substrate support member and which is alignable with the substrate to provide a minimum gap between the edge of the substrate and the ring.
    Type: Grant
    Filed: February 23, 1994
    Date of Patent: September 1, 1998
    Assignee: Applied Materials, Inc.
    Inventors: Karl Littau, Lawrence Chung-lai Lei
  • Patent number: 5766365
    Abstract: A substrate processing apparatus comprising a processing chamber in which a substrate support is located. The substrate support, which is in the form of a heater pedestal, has a surface dimensioned to receive the substrate, and is circumscribed by a removable purge ring which defines an annulus between itself and the pedestal. At the outer edge of the pedestal is a purge gas manifold, in the form of a cavity between the purge ring and the pedestal. The lower end of the manifold is sealed by means of a mechanical seal that is formed at process temperature as the pedestal expands from heating and comes into contact with the purge ring's lower edge. The upper end of the manifold opens into the annulus defined by the purge ring and the pedestal. The manifold is arranged so that during processing, purge gas is injected into the manifold and projected toward the edge of a substrate received on the surface of the pedestal.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: June 16, 1998
    Assignee: Applied Materials, Inc.
    Inventors: Salvador P. Umotoy, Alan F. Morrison, Karl A. Littau, Richard A. Marsh, Lawrence Chung-Lai Lei
  • Patent number: 5695568
    Abstract: An improved deposition chamber deposits useful layers on substrates. The improved chamber includes a substrate edge protection system which, in combination with a purge gas, protects selected portions of the edge and underside of the substrate from the deposition gas while preventing the creation of a masked area on the substrate edge. The substrate is supported on a solid receiving plate, which is supported by a stem having a heat limiting member and a shroud to protect the stem and a positioning assembly aligns the substrate to the receiving plate.
    Type: Grant
    Filed: February 23, 1994
    Date of Patent: December 9, 1997
    Assignee: Applied Materials, Inc.
    Inventors: Ashok Sinha, Mei Chang, Ilya Perlov, Karl Littau, Alan Morrison, Lawrence Chung-Lai Lei
  • Patent number: 5516367
    Abstract: Vacuum CVD chambers are disclosed which provide a more uniformly deposited thin film on a substrate. The chamber susceptor mount for the substrate is heated resistively with a single coil firmly contacting the metal of the susceptor on all sides, providing uniform temperatures across the susceptor mount for a substrate. A purge gas line is connected to openings in the susceptor outside of the periphery of the substrate to prevent edge and backside contamination of the substrate. A vacuum feed line mounts the substrate to the susceptor plate during processing. A refractory purge guide, or a plurality of placement pins, maintain a fixed gap passage for the purge gases to pass alongside the edge of the wafer and into the processing area of the chamber. An exhaust pumping plate improves the uniformity of exhaustion of spent gases from the chamber.
    Type: Grant
    Filed: November 21, 1994
    Date of Patent: May 14, 1996
    Assignee: Applied Materials, Inc.
    Inventors: Lawrence C. Lei, Ilya Perlov, Karl A. Littau, Alan F. Morrison, Mei Chang, Ashok K. Sinha
  • Patent number: 5326725
    Abstract: A clamping ring having a downwardly extending finger that mates with a pocket in the periphery of a susceptor for supporting a wafer in a chemical vapor deposition chamber, provides alignment of the clamping ring, the wafer and the susceptor. A source of inert gas connected to the pocket provides a positive pressure in the pocket that prevents reactive gas in the chamber from reaching the edge and backside of the wafer. A source of vacuum connected to the susceptor support surface ensures good contact between the wafer and the susceptor.The clamping ring also has a lip extending over the top surface of the wafer having a rear surface that has a negative angle with respect to the upper surface of the clamping ring, providing a knife edge seal to the wafer, reducing the area of contact between the clamping ring and the wafer and providing a reduced area of thermal contact between the clamping ring and the wafer.
    Type: Grant
    Filed: March 11, 1993
    Date of Patent: July 5, 1994
    Assignee: Applied Materials, Inc.
    Inventors: Semyon Sherstinsky, Charles C. Harris, Mei Chang, Dale R. Du Bois, James F. Roberts, Susan Telford, Ronald L. Rose, Meng C. Tseng, Karl A. Littau