Patents by Inventor Robert Falster
Robert Falster 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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Publication number: 20180182641Abstract: The disclosure is directed to a method to recover the gate oxide integrity yield of a silicon wafer after rapid thermal anneal in an ambient atmosphere comprising a nitrogen containing gas, such as NH3 or N2. Generally, rapid thermal anneals in an ambient atmosphere comprising a nitrogen containing gas, such as NH3 or N2 to thereby imprint an oxygen precipitate profile can degrade the GOI yield of a silicon wafer by exposing as-grown crystal defects (oxygen precipitate) and vacancies generated by the silicon nitride film. The present invention restores GOI yield by stripping the silicon nitride layer, which is followed by wafer oxidation, which is followed by stripping the silicon oxide layer.Type: ApplicationFiled: December 13, 2017Publication date: June 28, 2018Inventors: Young Jung Lee, Jae-Woo Ryu, Byung Chun Kim, Robert Falster, Soon Sung Park, Tae Hoon Kim, Jun Hawn Ji, Carissima Marie Hudson
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Publication number: 20080020168Abstract: The present invention relates to a silicon on insulator (“SOI”) structure in which the device layer is derived from a single crystal Cz silicon wafer which has an axially symmetric region which is substantially free of agglomerated intrinsic point defects. The device layer of the silicon on insulator structure is single crystal Cz silicon having an axially symmetric region which is substantially free of agglomerated intrinsic point defects.Type: ApplicationFiled: August 3, 2007Publication date: January 24, 2008Applicant: MEMC ELECTRONIC MATERIALS, INC.Inventor: Robert Falster
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Publication number: 20070238266Abstract: This invention is directed to a process for heat-treating a single crystal silicon segment to influence the profile of minority carrier recombination centers in the segment. The segment is subjected to a heat-treatment to form crystal lattice vacancies, the vacancies being formed in the bulk of the silicon. The segment is then cooled at a rate which allows some, but not all, of the crystal lattice vacancies to diffuse to the front surface to produce a segment having the desired vacancy concentration profile. Platinum atoms are then in-diffused into the silicon matrix such that the resulting platinum concentration profile is substantially related to the concentration profile of the crystal lattice vacancies.Type: ApplicationFiled: June 14, 2007Publication date: October 11, 2007Applicant: MEMC ELECTRONIC MATERIALS, INC.Inventor: Robert Falster
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Publication number: 20070224783Abstract: The present invention is directed to a process for producing a silicon wafer which, during the heat treatment cycles of essentially any arbitrary electronic device manufacturing process, may form an ideal, non-uniform depth distribution of oxygen precipitates and may additionally contain an axially symmetric region which is substantially free of agglomerated intrinsic point defects. The process either comprises exposing the wafer's front and back surfaces to different atmospheres, or thermally annealing two wafers in a face-to-face arrangement.Type: ApplicationFiled: May 24, 2007Publication date: September 27, 2007Applicant: MEMC ELECTRONIC MATERIALS, INC.Inventors: Robert Falster, Joseph Holzer, Marco Cornara, Daniela Gambaro, Massimiliano Olmo, Steve Markgraf, Paolo Mutti, Seamus McQuaid, Bayard Johnson
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Publication number: 20070105279Abstract: A process for the preparation of low resistivity arsensic or phosphorous doped (N+/N++) silicon wafers which, during the heat treatment cycles of essentially any arbitrary electronic device manufacturing process, reliably form oxygen precipitates.Type: ApplicationFiled: November 9, 2005Publication date: May 10, 2007Applicant: MEMC Electronic Materials, Inc.Inventors: Robert Falster, Vladimir Voronkov, Gabriella Borionetti
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Publication number: 20060263967Abstract: The present invention generally relates to a high resistivity CZ silicon wafer, or a high resistivity silicon structure derived therefrom, and a process for the preparation thereof. In particular, the high resistivity silicon structure comprises a large diameter CZ silicon wafer as the substrate thereof, wherein the resistivity of the substrate wafer is decoupled from the concentration of acceptor atoms (e.g., boron) therein, the resistivity of the substrate being substantially greater than the resistivity as calculated based on the concentration of said acceptor atoms therein.Type: ApplicationFiled: May 18, 2006Publication date: November 23, 2006Applicant: MEMC Electronic Materials, Inc.Inventors: Robert Falster, Vladimir Voronkov, Galina Voronkova, Anna Batunina
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Publication number: 20060075960Abstract: A process for nucleating and growing oxygen precipitates in a silicon wafer, including subjecting a wafer having a non-uniform concentration of crystal lattice vacancies with the concentration of vacancies in the bulk layer being greater than the concentration of vacancies in the surface layer to a non-isothermal heat treatment to form of a denuded zone in the surface layer and to cause the formation and stabilization of oxygen precipitates having an effective radial size 0.5 nm to 30 nm in the bulk layer. The process optionally includes subjecting the stabilized wafer to a high temperature thermal process (e.g. epitaxial deposition, rapid thermal oxidation, rapid thermal nitridation and etc.) at temperatures in the range of 1000 OC to 1275 OC without causing the dissolution of the stabilized oxygen precipitates.Type: ApplicationFiled: November 21, 2005Publication date: April 13, 2006Applicant: MEMC Electronic Materials, Inc.Inventors: Marco Borgini, Daniela Gambaro, Marco Ravani, Michael Ries, Laura Sacchetti, Robert Standley, Robert Falster, Mark Stinson
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Publication number: 20050255671Abstract: The present invention is directed to a process for producing a silicon on insulator (SOI) structure having intrinsic gettering, wherein a silicon substrate is subjected to an ideal precipitating wafer heat treatment which enables the substrate, during the heat treatment cycles of essentially any arbitrary electronic device manufacturing process to form an ideal, non-uniform depth distribution of oxygen precipitates, and wherein a dielectric layer is formed beneath the surface of the wafer by implanting oxygen or nitrogen ions, or molecular oxygen, beneath the surface and annealing the wafer. Additionally, the silicon wafer may initially include an epitaxial layer, or an epitaxial layer may be deposited on the substrate during the process of the present invention.Type: ApplicationFiled: July 5, 2005Publication date: November 17, 2005Applicant: MEMC Electronic Materials, Inc.Inventors: Robert Falster, Jeffrey Libbert
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Publication number: 20050238905Abstract: The present invention relates to single crystal silicon, in ingot or wafer form, having an axially symmetric vacancy dominated region and an axially symmetric silicon self-interstitial dominated region. Both the vacancy dominated and the silicon self-interstitial dominated regions are substantially free of agglomerated intrinsic point defects. The vacancy dominated region has a radial width of at least 15 mm and/or includes the central axis and the silicon self-interstitial dominated region is annular in shape and extends radially outward from the vacancy dominated region to the peripheral edge of the ingot or wafer. In ingot form, the axially symmetric regions have an axial length which is at least 20% of the length of the constant diameter portion of the ingot.Type: ApplicationFiled: April 8, 2005Publication date: October 27, 2005Applicant: MEMC Electronic Materials, Inc.Inventors: Robert Falster, Joseph Holzer, Steve Markgraf, Paolo Mutti, Seamus McQuaid, Bayard Johnson
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Publication number: 20050205000Abstract: The present invention relates to single crystal silicon, in ingot or wafer form, which contains an axially symmetric region which is free of agglomerated intrinsic point defects, and a process for the preparation thereof. The process comprises controlling growth conditions, such as growth velocity, v, instantaneous axial temperature gradient, G0, and the cooling rate, within a range of temperatures at which silicon self-interstitials are mobile, in order to prevent the formation of these agglomerated defects. In ingot form, the axially symmetric region has a width, as measured from the circumferential edge of the ingot radially toward the central axis, which is at least about 30% the length of the radius of the ingot. The axially symmetric region additionally has a length, as measured along the central axis, which is at least about 20% the length of the constant diameter portion of the ingot.Type: ApplicationFiled: May 17, 2005Publication date: September 22, 2005Applicant: MEMC Electronic Materials, Inc.Inventors: Robert Falster, Joseph Holzer
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Publication number: 20050170610Abstract: The present invention is directed to a silicon wafer which, during the heat treatment cycles of essentially any arbitrary electronic device manufacturing process, may form an ideal, non-uniform depth distribution of oxygen precipitates and may additionally contain an axially symmetric region which is substantially free of agglomerated intrinsic point defects.Type: ApplicationFiled: February 16, 2005Publication date: August 4, 2005Applicant: MEMC Electronic Materials, Inc.Inventors: Robert Falster, Joseph Holzer, Marco Cornara, Daniela Gambaro, Massimiliano Olmo, Steve Markgraf, Paolo Mutti, Seamus McQuaid, Bayard Johnson
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Publication number: 20050160967Abstract: A process for producing a single crystal silicon wafer comprising a front surface, a back surface, a lateral surface joining the front and back surfaces, a central axis perpendicular to the front and back surfaces, and a segment which is axially symmetric about the central axis extending substantially from the front surface to the back surface in which crystal lattice vacancies are the predominant intrinsic point defect, the segment having a radial width of at least about 25% of the radius and containing agglomerated vacancy defects and a residual concentration of crystal lattice vacancies wherein (i) the agglomerated vacancy defects have a radius of less than about 70 nm and (ii) the residual concentration of crystal lattice vacancy intrinsic point defects is less than the threshold concentration at which uncontrolled oxygen precipitation occurs upon subjecting the wafer to an oxygen precipitation heat treatment.Type: ApplicationFiled: March 24, 2005Publication date: July 28, 2005Applicant: MEMC Electronic Materials, Inc.Inventors: Robert Falster, Vladimir Voronkov, Paolo Mutti, Francesco Bonoli
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Publication number: 20050158969Abstract: The present invention is directed to a single crystal Czochralski-type silicon wafer, and a process for the preparation thereof, which has at least a surface layer of high resistivity, the layer having an interstitial oxygen content which renders it incapable of forming thermal donors in an amount sufficient to affect resistivity upon being subjected to a conventional semiconductor device manufacturing process. The present invention further directed to a silicon on insulator structure derived from such a wafer.Type: ApplicationFiled: March 17, 2005Publication date: July 21, 2005Applicant: MEMC Electronic Materials, Inc.Inventors: Martin Binns, Robert Falster, Jeffrey Libbert
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Publication number: 20050132948Abstract: A process for the preparation of a silicon single ingot in accordance with the Czochralski method. The process for growing the single crystal silicon ingot comprises controlling (i) a growth velocity, v, (ii) an average axial temperature gradient, G0, during the growth of a constant diameter portion of the crystal over a temperature range from solidification to a temperature of no less than about 1325° C. to initially produce in the constant diameter portion of the ingot a series of predominant intrinsic point defects including vacancy dominated regions and silicon self interstitial dominated regions, alternating along the axis, and cooling the regions from the temperature of solidification at a rate which allows silicon self-interstitial atoms to diffuse radially to the lateral surface and to diffuse axially to vacancy dominated regions to reduce the concentration intrinsic point defects in each region.Type: ApplicationFiled: February 16, 2005Publication date: June 23, 2005Applicant: MEMC Electronic Materials, Inc.Inventors: Vladimir Vornokov, Robert Falster, Mohsen Banan
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Publication number: 20050130394Abstract: The present invention relates to a process for the preparation of a silicon on insulator wafer. The process includes implanting oxygen into a single crystal silicon wafer which is substantially free of agglomerated vacancy-type defects. The present invention further relates to a process for the preparation of a silicon on insulator wafer wherein oxygen is implanted into a single crystal silicon wafer having an axially symmetric region in which there is a predominant intrinsic point defect which is substantially free of agglomerated intrinsic point defects. Additionally, the present invention relates to a silicon on insulator (“SOI”) structure in which the device layer is substantially free of agglomerated intrinsic point defects.Type: ApplicationFiled: October 12, 2004Publication date: June 16, 2005Inventor: Robert Falster
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Publication number: 20050006796Abstract: A process for heat-treating a single crystal silicon segment to influence the profile of minority carrier recombination centers in the segment. The segment has a front surface, a back surface, and a central plane between the front and back surfaces. In the process, the segment is subjected to a heat-treatment to form crystal lattice vacancies, the vacancies being formed in the bulk of the silicon. The segment is then cooled from the temperature of said heat treatment at a rate which allows some, but not all, of the crystal lattice vacancies to diffuse to the front surface to produce a segment having a vacancy concentration profile in which the peak density is at or near the central plane with the concentration generally decreasing in the direction of the front surface of the segment. Platinum atoms are then in-diffused into the silicon matrix such that the resulting platinum concentration profile is substantially related to the concentration profile of the crystal lattice vacancies.Type: ApplicationFiled: August 5, 2004Publication date: January 13, 2005Inventor: Robert Falster
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Publication number: 20050005841Abstract: The present invention is directed to a single crystal Czochralski-type silicon wafer, and a process for the preparation thereof, which has a non-uniform distribution of stabilized oxygen precipitate nucleation centers therein. Specifically, the peak concentration is located in the wafer bulk and a precipitate-free zone extends inward from a surface.Type: ApplicationFiled: July 8, 2003Publication date: January 13, 2005Inventors: Robert Falster, Vladimir Voronkov
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Patent number: 6586068Abstract: A process for heat-treating a single crystal silicon wafer to influence the precipitation behavior of oxygen in the wafer in a subsequent thermal processing step. The wafer has a front surface, a back surface, and a central plane between the front and back surfaces. In the process, the wafer is subjected to a heat-treatment to form crystal lattice vacancies in the wafer. During the heat-treatment, the front and back surfaces of the wafer are each exposed to either a nitriding or non-nitriding gas. The wafer is then cooled from the temperature of said heat treatment at a rate which allows some, but not all, of the crystal lattice vacancies to diffuse to the front surface to produce a wafer having a vacancy concentration profile determined in part by the gas that each surface is exposed to and in part by the cooling rate.Type: GrantFiled: November 2, 2000Date of Patent: July 1, 2003Assignee: MEMC Electronic Materials, Inc.Inventors: Robert Falster, Marco Cornara, Daniela Gambaro, Massimiliano Olmo
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Publication number: 20020026893Abstract: A process for heat-treating a single crystal silicon wafer to influence the precipitation behavior of oxygen in the wafer in a subsequent thermal processing step. The wafer has a front surface, a back surface, a central plane between the front and back surfaces, and a sink for crystal lattice vacancies at the front surface. In the process, the wafer is subjected to a heat-treatment to form crystal lattice vacancies, the vacancies being formed in the bulk of the silicon. The wafer is then cooled from the temperature of said heat treatment at a rate which allows some, but not all, of the crystal lattice vacancies to diffuse to the crystal lattice vacancy sink to produce a wafer having a vacancy concentration profile in which the peak density is at or near the central plane with the concentration generally decreasing in the direction of the front surface of the wafer.Type: ApplicationFiled: August 13, 2001Publication date: March 7, 2002Inventors: Robert Falster, Marco Cornara, Daniela Gambaro, Massimiliano Olmo
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Publication number: 20020007779Abstract: The present invention relates to single crystal silicon, in ingot or wafer form, which contains an axially symmetric region which is free of agglomerated intrinsic point defects, and a process for the preparation thereof. The process for growing the single crystal silicon ingot comprises controlling (i) a growth velocity, v, (ii) an average axial temperature gradient, G0, during the growth of a constant diameter portion of the crystal over a temperature range from solidification to a temperature of no less than about 1325° C., and (iii) a cooling rate of the crystal from a solidification temperature to about 1,050° C., in order to cause the formation of an axially symmetrical segment which is substantially free of agglomerated intrinsic point defects.Type: ApplicationFiled: December 30, 1999Publication date: January 24, 2002Inventors: LUCIANO MULE'STAGNO, ROBERT FALSTER