Patents by Inventor Kristian E. Johnsgard
Kristian E. Johnsgard 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).
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Patent number: 7176417Abstract: A resistive heater having a doped ceramic heating element embedded either partially or completely within a matrix of undoped ceramic material. The ceramic may be silicon carbide, and the dopant may be nitrogen. Many of the advantages of the present heater stern from the fact that the materials used for the heating elements and the matrix material surrounding those elements have substantially the same coefficient of thermal expansion. In one embodiment, the heater is a monolithic plate that is compact, strong, robust, and low in thermal mass, allowing it to respond quickly to power input variations. The resistive heater may be used in many of the reactors and processing chambers used to fabricate integrated circuits, such as those that deposit epitaxial films, and carry out rapid thermal processing.Type: GrantFiled: November 15, 2001Date of Patent: February 13, 2007Assignee: Mattson Technology, Inc.Inventors: Kristian E. Johnsgard, Daniel L. Messineo, David E. Sallows
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Patent number: 6902622Abstract: Systems and methods for epitaxial deposition. The reactor includes a hot wall process cavity enclosed by a heater system, a thermal insulation system, and chamber walls. The walls of the process cavity may comprises a material having a substantially similar coefficient thermal expansion as the semiconductor substrate, such as quartz and silicon carbide, and may include an isothermal or near isothermal cavity that may be heated to temperatures as high as 1200 degrees C. Process gases may be injected through a plurality of ports, and are capable of achieving a fine level of distribution control of the gas components, including the film source gas, dopant source gas, and carrier gas. The gas supply system includes additional methods of delivering gas to the process cavity, such as through temperature measurement devices, and through a showerhead.Type: GrantFiled: April 10, 2002Date of Patent: June 7, 2005Assignee: Mattson Technology, Inc.Inventors: Kristian E. Johnsgard, David E. Sallows, Daniel L. Messineo, Robert D. Mailho, Mark W. Johnsgard
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Publication number: 20030124820Abstract: Systems and methods for epitaxial deposition. The reactor includes a hot wall process cavity enclosed by a heater system, a thermal insulation system, and chamber walls. The walls of the process cavity may comprises a material having a substantially similar coefficient thermal expansion as the semiconductor substrate, such as quartz and silicon carbide, and may include an isothermal or near isothermal cavity that may be heated to temperatures as high as 1200 degrees C. Process gases may be injected through a plurality of ports, and are capable of achieving a fine level of distribution control of the gas components, including the film source gas, dopant source gas, and carrier gas. The gas supply system includes additional methods of delivering gas to the process cavity, such as through temperature measurement devices, and through a showerhead. In one embodiment of the present invention, the system is capable of utilizing silane as a silicon source gas.Type: ApplicationFiled: April 10, 2002Publication date: July 3, 2003Inventors: Kristian E. Johnsgard, David E. Sallows, Daniel L. Messineo, Robert D. Mailho, Mark W. Johnsgard
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Patent number: 6436796Abstract: A thermal processing system and method for processing a semiconductor substrate. An inductor couples energy to a susceptor, wherein the spacing between the inductor and the susceptor is configured for the steady-state portions of a CVD epitaxial deposition process. The temperature uniformity of the susceptor is improved during the transient portions of the process, the heat ramp-up and cool down, by varying the distance of separation between the inductor and the susceptor. Temperature non-uniformities are a common cause of slip. Additional aspects of the invention provide for improved thermal shielding of the edges and top surface of the susceptor. Thicker susceptors also improve temperature uniformity.Type: GrantFiled: January 31, 2000Date of Patent: August 20, 2002Assignee: Mattson Technology, Inc.Inventors: Robert D. Mailho, Mark J. O'Hara, Glenn A. Pfefferkorn, Gary Lee Evans, Kristian E. Johnsgard
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Publication number: 20020100753Abstract: A resistive heater comprising a doped ceramic heating element embedded either partially or completely within a matrix of undoped ceramic material. The ceramic may be silicon carbide, and the dopant may be nitrogen. Many of the advantages of the present heater stem from the fact that the materials comprising the heating elements and the matrix material surrounding those elements have substantially the same coefficient of thermal expansion. In one embodiment, the heater is a monolithic plate that is compact, strong, robust, and low in thermal mass, allowing it to respond quickly to power input variations. The resistive heater may be used in many of the reactors and processing chambers used to fabricate integrated circuits, such as those that deposit epitaxial films, and carry out rapid thermal processing.Type: ApplicationFiled: November 15, 2001Publication date: August 1, 2002Inventors: Kristian E. Johnsgard, Daniel L. Messineo, David E. Sallows
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Patent number: 6403925Abstract: A semiconductor substrate processing system and method using a stable heating source with a large thermal mass relative to conventional lamp heated systems. The system dimensions and processing parameters are selected to provide a substantial heat flux to the wafer while minimizing heat loss to the surrounding environment (particularly from the edges of the heat source and wafer). The heat source provides a wafer temperature uniformity profile that has a low variance across temperature ranges at low pressures. A resistively heated block is substantially enclosed within an insulated vacuum cavity used to heat the wafer. A vacuum region is preferably provided between the heated block and the insulating material as well as between the insulating material and the chamber wall. Heat transfer across the vacuum regions is primarily achieved by radiation, while heat transfer through the insulating material is achieved by conduction.Type: GrantFiled: October 25, 2000Date of Patent: June 11, 2002Assignee: Mattson Technology, Inc.Inventors: Kristian E. Johnsgard, Brad S. Mattson, James McDiarmid, Vladimir J. Zeitlin
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Patent number: 6399921Abstract: A semiconductor substrate processing system and method using a stable heating source with a large thermal mass relative to conventional lamp heated systems. The system dimensions and processing parameters are selected to provide a substantial heat flux to the wafer while minimizing heat loss to the surrounding environment (particularly from the edges of the heat source and wafer). The heat source provides a wafer temperature uniformity profile that has a low variance across temperature ranges at low pressures. A resistively heated block is substantially enclosed within an insulated vacuum cavity used to heat the wafer. Insulating walls comprising a reflective material, such as polished tungsten, encapsulated within an inert insulating material such as quartz, may be used to provide insulation. The isothermal nature of the processing region may be enhanced by using multiple layers of insulating walls, actively heated insulating walls or a conductive gas to enhance heat transfer to the semiconductor substrate.Type: GrantFiled: January 25, 2000Date of Patent: June 4, 2002Assignee: Mattson Technology, Inc.Inventors: Kristian E. Johnsgard, Brad S. Mattson, James McDiarmid, Vladimir J. Zeitlin
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Publication number: 20020047004Abstract: A semiconductor substrate processing system and method using a stable heating source with a large thermal mass relative to conventional lamp heated systems. The system dimensions and processing parameters are selected to provide a substantial heat flux to the wafer while minimizing heat loss to the surrounding environment (particularly from the edges of the heat source and wafer). The heat source provides a wafer temperature uniformity profile that has a low variance across temperature ranges at low pressures. A resistively heated block is substantially enclosed within an insulated vacuum cavity used to heat the wafer. Insulating walls comprising a reflective material, such as polished tungsten, encapsulated within an inert insulating material, such as quartz, may be used to provide insulation. The isothermal nature of the processing region may be enhanced by using multiple layers of insulating walls, actively heated insulating walls or a conductive gas to enhance heat transfer to the semiconductor substrate.Type: ApplicationFiled: January 25, 2000Publication date: April 25, 2002Inventors: Kristian E. Johnsgard, Brad S. Mattson, James McDiarmid, Vladimir J. Zeitlin
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Patent number: 6342691Abstract: A semiconductor substrate processing system and method of using a stable heating source with a large thermal mass relative to conventional lamp heating systems. The system dimensions and processing parameters are selected to provide a substantial heat flux to the substrate while reducing the potential of heat loss to the surrounding environment, particularly from the edges of the heat source and substrate. Aspects of the present invention include a dual resistive heater system comprising a base or primary heater, surrounded by a peripheral or edge heater. The impedance of the edge heater may be substantially matched to that of the primary heater such that a single power supply may be used to supply power to both heaters. Both resistive heaters deliver heat to a heated block, and the heaters and heated block are substantially enclosed within an insulated cavity. The walls of the insulated cavity may include multiple layers of insulation, and these layers may be substantially concentrically arranged.Type: GrantFiled: November 12, 1999Date of Patent: January 29, 2002Assignee: Mattson Technology, Inc.Inventors: Kristian E. Johnsgard, Jean-François Daviet, James A. Givens, Stephen E. Savas, Brad S. Mattson, Ashur J. Atanos
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Patent number: 6301434Abstract: A thermal processing system and method for processing a semiconductor substrate. A lamp system radiates through a window to heat the substrate. A dual gas manifold provides purge gas through a top showerhead to prevent deposits on the window and provides gas through a lower showerhead to deposit a material on the substrate. A thin support and a radiative cavity with thin radiation shields is used to support and insulate the substrate. A peripheral heater also heats the edges to enhance uniformity. An opaque quartz liner is used to reduce contaminants and undesired deposits and simplify cleaning.Type: GrantFiled: March 22, 1999Date of Patent: October 9, 2001Assignee: Mattson Technology, Inc.Inventors: James McDiarmid, Kristian E. Johnsgard, Steven E. Parks, Mark W. Johnsgard
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Patent number: 6200634Abstract: System and method for determining thermal characteristics, such as temperature, temperature uniformity and emissivity, during thermal processing using shielded pyrometry. The surface of a semiconductor substrate is shielded to prevent interference from extrinsic light from radiant heating sources and to form an effective black-body cavity. An optical sensor is positioned to sense emitted light in the cavity for pyrometry. The effective emissivity of the cavity approaches unity independent of the semiconductor substrate material which simplifies temperature calculation. The shield may be used to prevent undesired backside deposition. Multiple sensors may be used to detect temperature differences across the substrate and in response heaters may be adjusted to enhance temperature uniformity.Type: GrantFiled: August 14, 1998Date of Patent: March 13, 2001Assignee: Mattson Technology, Inc.Inventors: Kristian E. Johnsgard, James McDiarmid
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Patent number: 6172337Abstract: A semiconductor substrate processing system and method using a stable heating source with a large thermal mass relative to conventional lamp heated systems. The system dimensions and processing parameters are selected to provide a substantial heat flux to the wafer while minimizing heat loss to the surrounding environment (particularly from the edges of the heat source and wafer). The heat source provides a wafer temperature uniformity profile that has a low variance across temperature ranges at low pressures. A resistively heated block is substantially enclosed within an insulated vacuum cavity used to heat the wafer. A vacuum region is preferably provided between the heated block and the insulating material as well as between the insulating material and the chamber wall. Heat transfer across the vacuum regions is primarily achieved by radiation, while heat transfer through the insulating material is achieved by conduction.Type: GrantFiled: July 8, 1999Date of Patent: January 9, 2001Assignee: Mattson Technology, Inc.Inventors: Kristian E. Johnsgard, Brad S. Mattson, James McDiarmid, Vladimir J. Zeitlin
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Patent number: 6046439Abstract: A semiconductor substrate processing system and method using a stable heating source with a large thermal mass relative to conventional lamp heated systems. The system dimensions and processing parameters are selected to provide a substantial heat flux to the wafer while minimizing heat loss to the surrounding environment (particularly from the edges of the heat source and wafer). The heat source provides a wafer temperature uniformity profile that has a low variance across temperature ranges at low pressures. A resistively heated block is substantially enclosed within an insulated vacuum cavity used to heat the wafer. Insulating walls comprising a reflective material, such as polished tungsten, encapsulated within an inert insulating material, such as quartz, may be used to provide insulation. The isothermal nature of the processing region may be enhanced by using multiple layers of insulating walls, actively heated insulating walls or a conductive gas to enhance heat transfer to the semiconductor substrate.Type: GrantFiled: June 16, 1997Date of Patent: April 4, 2000Assignee: Mattson Technology, Inc.Inventors: Kristian E. Johnsgard, Brad S. Mattson, James McDiarmid, Vladimir J. Zeitlin
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Patent number: 6043460Abstract: A semiconductor substrate processing system and method using a stable heating source with a large thermal mass relative to conventional lamp heated systems. The system dimensions and processing parameters are selected to provide a substantial heat flux to the wafer while minimizing heat loss to the surrounding environment (particularly from the edges of the heat source and wafer). The heat source provides a wafer temperature uniformity profile that has a low variance across temperature ranges at low pressures. A resistively heated block is substantially enclosed within an insulated vacuum cavity used to heat the wafer. A vacuum region is preferably provided between the heated block and the insulating material as well as between the insulating material and the chamber wall. Heat transfer across the vacuum regions is primarily achieved by radiation, while heat transfer through the insulating material is achieved by conduction.Type: GrantFiled: July 8, 1999Date of Patent: March 28, 2000Assignee: Mattson Technology, Inc.Inventors: Kristian E. Johnsgard, Brad S. Mattson, James McDiarmid, Vladimir J. Zeitlin
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Patent number: 6002109Abstract: A semiconductor substrate processing system and method using a stable heating source with a large thermal mass relative to conventional lamp heated systems. The system dimensions and processing parameters are selected to provide a substantial heat flux to the wafer while minimizing heat loss to the surrounding environment (particularly from the edges of the heat source and wafer). The heat source provides a wafer temperature uniformity profile that has a low variance across temperature ranges at low pressures. A resistively heated block is substantially enclosed within an insulated vacuum cavity used to heat the wafer. A vacuum region is preferably provided between the heated block and the insulating material as well as between the insulating material and the chamber wall. Heat transfer across the vacuum regions is primarily achieved by radiation, while heat transfer through the insulating material is achieved by conduction.Type: GrantFiled: July 10, 1995Date of Patent: December 14, 1999Assignee: Mattson Technology, Inc.Inventors: Kristian E. Johnsgard, Brad S. Mattson, James McDiarmid, Vladimir J. Zeitlin
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Patent number: 5830277Abstract: System and method for determining thermal characteristics, such as temperature, temperature uniformity and emissivity, during thermal processing using shielded pyrometry. The surface of a semiconductor substrate is shielded to prevent interference from extrinsic light from radiant heating sources and to form an effective black-body cavity. An optical sensor is positioned to sense emitted light in the cavity for pyrometry. The effective emissivity of the cavity approaches unity independent of the semiconductor substrate material which simplifies temperature calculation. The shield may be used to prevent undesired backside deposition. Multiple sensors may be used to detect temperature differences across the substrate and in response heaters may be adjusted to enhance temperature uniformity.Type: GrantFiled: May 26, 1995Date of Patent: November 3, 1998Assignee: Mattson Technology, Inc.Inventors: Kristian E. Johnsgard, James McDiarmid
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Patent number: 5493987Abstract: A CVD reactor and method for growing semiconductor material upon a selected surface of a semiconductor wafer supported within the reactor includes a plurality of heat shields that are arranged relative to the peripheral edge and underside of the wafer to alter the radiation of flux from the wafer that is heated to elevated temperatures by a bank of high-intensity lamps that are oriented to illuminate the upper side of the wafer through a transparent wall of the reactor. A reactant gas flowing into the chamber from above the wafer is inhibited from flowing about the underside of the wafer, thereby assuring wafers that are not contaminated on the underside.Type: GrantFiled: May 16, 1994Date of Patent: February 27, 1996Assignee: AG Associates, Inc.Inventors: James McDiarmid, Kristian E. Johnsgard
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Patent number: 5324684Abstract: A technique for doping silicon material or other semiconductors uses gas phase dopant sources under reduced pressure in a radiantly heated, cold-wall reactor. The technique is applied to the automated integrated circuit manufacturing techniques being adopted in modern fabrication facilities. The method includes placing a substrate comprising semiconductor material on a thermally isolated support structure in a reduced pressure, cold-wall reaction chamber; radiantly heating the substrate within the reaction chamber to a controlled temperature; flowing a gas phase source of dopant at controlled pressure and concentration in contact with the substrate so that the dopant is absorbed by the substrate, and annealing the substrate. The substrate may be first coated with a layer of polycrystalline semiconductor, and then gas phase doping as described above may be applied to the polycrystalline layer.Type: GrantFiled: February 25, 1992Date of Patent: June 28, 1994Assignee: AG Processing Technologies, Inc.Inventors: Ahmad Kermani, Kristian E. Johnsgard, Carl Galewski