Patents by Inventor John Forster
John Forster 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: 6673724Abstract: The present invention provides a method and apparatus for achieving conformal step coverage of one or more materials on a substrate using sputtered ionized material. A target provides a source of material to be sputtered by a plasma and then ionized by an inductive coil, thereby producing electrons and ions. In one embodiment, one or both of the signals to the substrate and the target are modulated. Preferably, the modulated signal to the substrate includes a negative voltage portion and a zero voltage portion.Type: GrantFiled: November 7, 2001Date of Patent: January 6, 2004Assignee: Applied Materials, Inc.Inventors: John Forster, Praburam Gopalraja, Bradley O. Stimson, Liubo Hong
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Publication number: 20020144901Abstract: A sputtering coil for a plasma chamber in a semiconductor fabrication system is provided. The sputtering coil couples energy into a plasma and also provides a source of sputtering material to be sputtered onto a workpiece from the coil to supplement material being sputtered from a target onto the workpiece. Alternatively a plurality of coils may be provided, one primarily for coupling energy into the plasma and the other primarily for providing a supplemental source of sputtering material to be sputtered on the workpiece.Type: ApplicationFiled: January 17, 2002Publication date: October 10, 2002Inventors: Jaim Nulman, Sergio Edelstein, Mani Subramani, Zheng Xu, Howard Grunes, Avi Tepman, John Forster, Praburam Gopalraja
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Patent number: 6418638Abstract: A control system and method for a dryer used to dry a line of gypsum boards. The control system automates control of the dryer by measuring the amount of water used at the mixer to produce board segments and determining a desired amount of water to be evaporated for each board segment based on the measured value. The desired amount of water to be evaporated for each board segment is tracked through the production line and the total evaporation load of each dryer zone is continuously calculated based on the board segments located in the dryer zone at a given time. The dryer zone differential temperature is adjusted according to the calculated evaporation load. When a board is rejected from the board line, the desired amounts of water to be evaporated of its corresponding board segments are set to zero, thus signifying a gap.Type: GrantFiled: January 14, 2000Date of Patent: July 16, 2002Assignee: Westroc, Inc.Inventors: John Forster, Stephen Dennis, Jean-Louis Mongrolle
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Publication number: 20020089027Abstract: The present invention pertains to a carrier layer and a contact enabled by the carrier layer which enables the fabrication of aluminum (including aluminum alloys and other conductive materials having a similar melting point) electrical contacts in multilayer integrated circuit vias, through holes, or trenches having an aspect ratio greater than one. In fact, the structure has been shown to enable such contact fabrication in vias, through holes, and trenches having aspect ratios as high as at least 5:1, and should be capable of filing apertures having aspect ratios up to about 12:1. The carrier layer, in addition to permitting the formation of a conductive contact at high aspect ratio, provides a diffusion barrier which prevents the aluminum from migrating into surrounding substrate material which operates in conjunction with the electrical contact.Type: ApplicationFiled: March 6, 2002Publication date: July 11, 2002Inventors: Zheng Xu, John Forster, Tse-Yong Yao
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Publication number: 20020068464Abstract: The present invention provides a method and apparatus for achieving conformal step coverage of one or more materials on a substrate using sputtered ionized material. A target provides a source of material to be sputtered by a plasma and then ionized by an inductive coil, thereby producing electrons and ions. In one embodiment, one or both of the signals to the substrate and the target are modulated. Preferably, the modulated signal to the substrate includes a negative voltage portion and a zero voltage portion.Type: ApplicationFiled: November 7, 2001Publication date: June 6, 2002Applicant: Applied Materials, Inc.Inventors: John Forster, Praburam Gopalraja, Bradley O. Stimson, Liubo Hong
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Patent number: 6368469Abstract: A sputtering coil for a plasma chamber in a semiconductor fabrication system is provided. The sputtering coil couples energy into a plasma and also provides a source of sputtering material to be sputtered onto a workpiece from the coil to supplement material being sputtered from a target onto the workpiece. Alternatively a plurality of coils may be provided, one primarily for coupling energy into the plasma and the other primarily for providing a supplemental source of sputtering material to be sputtered on the workpiece.Type: GrantFiled: May 6, 1997Date of Patent: April 9, 2002Assignee: Applied Materials, Inc.Inventors: Jaim Nulman, Sergio Edelstein, Mani Subramani, Zheng Xu, Howard Grunes, Avi Tepman, John Forster, Praburam Gopalraja
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Patent number: 6344419Abstract: The present invention provides a method and apparatus for achieving conformal step coverage of one or more materials on a substrate using sputtered ionized material. A target provides a source of material to be sputtered by a plasma and then ionized by an inductive coil, thereby producing electrons and ions. In one embodiment, one or both of the signals to the substrate and the target are modulated. Preferably, the modulated signal to the substrate includes a negative voltage portion and a zero voltage portion.Type: GrantFiled: December 3, 1999Date of Patent: February 5, 2002Assignee: Applied Materials, Inc.Inventors: John Forster, Praburam Gopalraja, Bradley O. Stimson, Liubo Hong
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Patent number: 6313027Abstract: The present invention pertains to a carrier layer and a contact enabled by the carrier layer which enables the fabrication of aluminum (including aluminum alloys and other conductive materials having a similar melting point) electrical contacts in multilayer integrated circuit vias, through holes, or trenches having an aspect ratio greater than one. In fact, the structure has been shown to enable such contact fabrication in vias, through holes, and trenches having aspect ratios as high as at least 5:1, and should be capable of filing apertures having aspect ratios up to about 12:1. The carrier layer, in addition to permitting the formation of a conductive contact at high aspect ratio, provides a diffusion barrier which prevents the aluminum from migrating into surrounding substrate material which operates in conjunction with the electrical contact.Type: GrantFiled: October 6, 1997Date of Patent: November 6, 2001Assignee: Applied Materials, Inc.Inventors: Zheng Xu, John Forster, Tse-Yong Yao
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Patent number: 6306265Abstract: A magnetron especially advantageous for low-pressure plasma sputtering or sustained self-sputtering having reduced area but full target coverage. The magnetron includes an outer pole face surrounding an inner pole face with a gap therebetween. The outer pole of the magnetron of the invention is smaller than that of a circular magnetron similarly extending from the center to the periphery of the target. A preferred triangular shape having a small apex angle of 20 to 30° may be formed from outer bar magnets of one magnetic polarity enclosing an inner magnet of the other magnetic polarity. The magnetron allows the generation of plasma waves in the neighborhood of 22 MHz which interact with the 1 to 20 eV electrons of the plasma to thereby increase the plasma density.Type: GrantFiled: April 11, 2000Date of Patent: October 23, 2001Assignee: Applied Materials, Inc.Inventors: Jianming Fu, Praburam Gopalraja, Fusen Chen, John Forster
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Patent number: 6297595Abstract: A method and apparatus for generating a plasma by inductively coupling electromagnetic energy into the plasma. In one embodiment, first and second antenna coils are disposed about the circumference of the plasma containment area. The first and second antenna coils are relatively spaced along the longitudinal axis of the plasma containment area. A current is generated in the first and second antenna coils. A phase shift regulating network establishes a difference between the phase of the current in the first antenna and the phase of the current in the second antenna. The phase difference corresponds to the phase difference required to launch a helicon wave in the plasma. In a second embodiment, a chamber shield is made of a conductive material and is coupled to the RF source such that the shield functions as an RF antenna. The shield may be coupled in series to a coil surrounding the shield to increase the resultant flux density.Type: GrantFiled: March 27, 1998Date of Patent: October 2, 2001Assignee: Applied Materials, Inc.Inventors: Bradley O. Stimson, John Forster
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Patent number: 6264812Abstract: A method and apparatus for generating a plasma by inductively coupling electromagnetic energy into the plasma. In one embodiment, first and second antenna coils are disposed about the circumference of the plasma containment area. The first and second antenna coils are relatively spaced along the longitudinal axis of the plasma containment area. A current is generated in the first and second antenna coils. A phase shift regulating network establishes a difference between the phase of the current in the first antenna and the phase of the current in the second antenna. The phase difference corresponds to the phase difference required to launch a helicon wave in the plasma. In a second embodiment, a chamber shield is made of a conductive material and is coupled to the RF source such that the shield functions as an RF antenna. The shield may be coupled in series to a coil surrounding the shield to increase the resultant flux density.Type: GrantFiled: November 15, 1995Date of Patent: July 24, 2001Assignee: Applied Materials, Inc.Inventors: Ivo J. Raaijmakers, Bradley O. Stimson, John Forster
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Patent number: 6228229Abstract: A method and apparatus for generating a plasma by inductively coupling electromagnetic energy into the plasma. In one embodiment, first and second antenna coils are disposed about the circumference of the plasma containment area. The first and second antenna coils are relatively spaced along the longitudinal axis of the plasma containment area. A current is generated in the first and second antenna coils. A phase shift regulating network establishes a difference between the phase of the current in the first antenna and the phase of the current in the second antenna. The phase difference corresponds to the phase difference required to launch a helicon wave in the plasma. In a second embodiment, a chamber shield is made of a conductive material and is coupled to the RF source such that the shield functions as an RF antenna. The shield may be coupled in series to a coil surrounding the shield to increase the resultant flux density.Type: GrantFiled: March 27, 1998Date of Patent: May 8, 2001Assignee: Applied Materials, Inc.Inventors: Ivo J. Raaijmakers, Bradley O. Stimson, John Forster
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Patent number: 6217721Abstract: An aluminum sputtering process, particularly useful for filling vias and contacts of high aspect ratios formed through a dielectric layer and also usefull for forming interconnects that are highly resistant to electromigration. A liner or barrier layer is first deposited by a high-density plasma (HDP) physical vapor deposition (PVD, also called sputtering) process, such as is done with an inductively coupled plasma. If a contact is connected at its bottom to a silicon element, the first sublayer of the liner layer is a Ti layer, which is silicided to the silicon substrate. The second sublayer comprises TiN, which not only acts as a barrier against the migration of undesirable components into the underlying silicon but also when deposited with an HDP process and biased wafer forms a dense, smooth crystal structure. The third sublayer comprises Ti and preferably is graded from TiN to Ti. Over the liner layer, an aluminum layer is deposited in a standard, non-HDP process.Type: GrantFiled: April 5, 1996Date of Patent: April 17, 2001Assignee: Applied Materials, Inc.Inventors: Zheng Xu, John Forster, Tse-Yong Yao, Jaim Nulman, Fusen Chen
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Patent number: 6193855Abstract: The present invention provides a method and apparatus for achieving conformal step coverage of one or more materials on a substrate using sputtered ionized material. A plasma is struck and maintained in a processing region by coupling energy into one or more gases. A target disposed in the processing region provides a source of material to be sputtered and then ionized in the plasma environment. During deposition of material onto the substrate, the plasma density is modulated by varying the energy supplied to the plasma. During a period of plasma decay, a bias to a substrate support member is increased to a relatively higher power to periodically enhance the attraction of positively charged particles to the substrate during the afterglow period of the plasma. In one embodiment, a bias to the target is also modulated.Type: GrantFiled: October 19, 1999Date of Patent: February 27, 2001Assignee: Applied Materials, Inc.Inventors: Praburam Gopalraja, John Forster
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Patent number: 6176981Abstract: A plasma reactor for physical vapor deposition (PVD), also known as sputtering, which is adapted so that the atomic species sputtered from the target can self-sustain the plasma without the need of a working gas such as argon. The method is particularly useful for sputtering copper. According to the invention, a bias ring arranged around the wafer and rising somewhat above it is positively electrically biased to control the plasma potential, and hence to control the energy and directionality of the ions being sputter deposited on the wafer. The bias ring may be a separate biasing element which can be positioned at a selected height above the wafer.Type: GrantFiled: November 16, 1998Date of Patent: January 23, 2001Assignee: Applied Materials, Inc.Inventors: Liubo Hong, John Forster, Jianming Fu
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Patent number: 6136095Abstract: The present invention pertains to a carrier layer and a contact enabled by the carrier layer which enables the fabrication of aluminum (including aluminum alloys and other conductive materials having a similar melting point) electrical contacts in multilayer integrated circuit vias, through holes, or trenches having an aspect ratio greater than one. In fact, the structure has been shown to enable such contact fabrication in vias, through holes, and trenches having aspect ratios as high as at least 5:1, and should be capable of filing apertures having aspect ratios up to about 12:1. The carrier layer, in addition to permitting the formation of a conductive contact at high aspect ratio, provides a diffusion barrier which prevents the aluminum from migrating into surrounding substrate material which operates in conjunction with the electrical contact.Type: GrantFiled: October 6, 1997Date of Patent: October 24, 2000Assignee: Applied Materials, Inc.Inventors: Zheng Xu, John Forster, Tse-Yong Yao
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Patent number: 5962923Abstract: The present invention pertains to a carrier layer and a contact enabled by the carrier layer which enables the fabrication of aluminum (including aluminum alloys and other conductive materials having a similar melting point) electrical contacts in multilayer integrated circuit vias, through holes, or trenches having an aspect ratio greater than one. In fact, the structure has been shown to enable such contact fabrication in vias, through holes, and trenches having aspect ratios as high as at least 5:1, and should be capable of filing apertures having aspect ratios up to about 12:1. The carrier layer, in addition to permitting the formation of a conductive contact at high aspect ratio, provides a diffusion barrier which prevents the aluminum from migrating into surrounding substrate material which operates in conjunction with the electrical contact.Type: GrantFiled: August 7, 1995Date of Patent: October 5, 1999Assignee: Applied Materials, Inc.Inventors: Zheng Xu, John Forster, Tse-Yong Yao
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Patent number: 5897752Abstract: A plasma reactor for physical vapor deposition (PVD), also known as sputtering, which is adapted so that the atomic species sputtered from the target can self-sustain the plasma without the need of a working gas such as argon. The method is particularly useful for sputtering copper. According to the invention, a bias ring arranged around the wafer and rising above it is electrically biased to control the plasma potential, and hence to control the energy and directionality of the ions being sputter deposited on the wafer. The bias ring can be either a separate biasing element which can be positioned at a selected height above the wafer or a clamping ring clamping the wafer to the pedestal but having a biasing surface electrically insulated from the wafer and the pedestal.Type: GrantFiled: May 20, 1997Date of Patent: April 27, 1999Assignee: Applied Materials, Inc.Inventors: Liubo Hong, John Forster, Jianming Fu
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Patent number: 5763851Abstract: A coil shield assembly for an RF field coil in a plasma processing system includes a first shield positioned inside the coil. The first shield has a central opening substantially surrounding a central space of a processing chamber in which the plasma is maintained. At least one slot is formed in the first shield and extends therethrough. A barrier is positioned between the first shield and the coil and spaced apart from the first shield near the at least one slot. The slot permits an RF signal from the coil to couple with the plasma, and the first shield and the barrier are structured and arranged to prevent plasma ions or sputtered material from bombarding the coil by a direct path from the central space and through the at least one slot.Type: GrantFiled: July 3, 1996Date of Patent: June 9, 1998Assignee: Applied Materials, Inc.Inventors: John Forster, Aihua Chen, Howard Grunes, Robert B. Lowrance, Ralf Hofmann, Zheng Xu, Fernand Dorleans
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Patent number: 5685941Abstract: A plasma reactor for carrying out plasma processing of a semiconductor substrate includes a vacuum chamber including apparatus for introducing a gas into the interior thereof, an induction coil encircling a region of the vacuum chamber, the coil being connected across an RF power source, and an electrode positioned adjacent the region and connected to the RF power source for capacitively coupling RF power to the gas in the interior of the vacuum chamber. The electrode has a surface area facing the region which is large enough to provide capacitive coupling of RF power to the gas in the region sufficient to facilitate igniting a plasma, but which is small enough so that, during steady-state maintenance of the plasma, most of the RF power coupled to the plasma from the RF power source is coupled inductively rather than capacitively.Type: GrantFiled: November 21, 1995Date of Patent: November 11, 1997Assignee: Applied Materials, Inc.Inventors: John Forster, Barney M. Cohen, Bradley O. Stimson, George Proulx