Patents by Inventor Michael Kerstan

Michael Kerstan 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: 10707069
    Abstract: A method of polishing a semiconductor wafer includes polishing a surface of the semiconductor wafer using a polishing pad while supplying a polishing agent slurry containing abrasives during a first step. The polishing pad is free of abrasives and includes a first surface that contacts the semiconductor wafer, the first surface having a surface structure including elevations. Supply of polishing agent slurry is subsequently ended and, in a second step, the surface of the semiconductor wafer is polished using the polishing pad while supplying a polishing agent solution having a pH value of at least 12 that is free of solids.
    Type: Grant
    Filed: March 2, 2011
    Date of Patent: July 7, 2020
    Assignee: SILTRONIC AG
    Inventors: Juergen Schwandner, Michael Kerstan
  • Patent number: 9539695
    Abstract: Carriers suitable for receiving one or more semiconductor wafers for the machining thereof in lapping, grinding or polishing machines, comprise a core of a first material which has a high stiffness, the core being completely or partly coated with a second material, and also at least one cutout for receiving a semiconductor wafer, wherein the second material is a thermoset polyurethane elastomer having a Shore A hardness of 20-90. The carriers are preferably coated with the second material after chemical surface activation and application of adhesion promoter, and may be used for simultaneous double-side material-removing machining of a plurality of semiconductor wafers.
    Type: Grant
    Filed: October 1, 2008
    Date of Patent: January 10, 2017
    Assignees: Siltronic AG, Peter Wolters GmbH
    Inventors: Georg Pietsch, Michael Kerstan, Heiko aus dem Spring
  • Patent number: 9011209
    Abstract: A trimming apparatus for trimming two working layers, including bonded abrasive applied on mutually facing sides of an upper and a lower working disk of a grinding apparatus configured for simultaneous double-side processing of flat workpieces includes a trimming disk, a plurality of trimming bodies and an outer toothing, where the trimming bodies are configured to release abrasive substances upon contract with the working layers so as to effect material removal from the working layers. At least 80% of the area of the trimming bodies configured to come into contact with the working layers is arranged within a ring-shaped region on the trimming disk. The width of the ring-shaped region is between 1-25% of the diameter of the trimming disk and the area of the trimming bodies which comes into contact with the working layers occupies 20-90% of the total area of the ring-shaped region.
    Type: Grant
    Filed: February 25, 2014
    Date of Patent: April 21, 2015
    Assignee: Siltronic AG
    Inventors: Georg Pietsch, Michael Kerstan
  • Patent number: 8986070
    Abstract: A method for trimming two working layers including bonded abrasive applied on mutually facing sides of an upper and a lower working disk of a grinding apparatus configured for simultaneous double-side processing of flat workpiece includes providing at least one trimming apparatus including a trimming disk, a plurality of trimming bodies and an outer toothing. The upper and lower working disks are rotated. The trimming apparatus is moved between the rotating working disks using a rolling apparatus and the outer toothing on cycloidal paths relative to working layers of the working disks. The working layers and the trimming body are brought into contact so as to release abrasive substances from the trimming bodies and so as to effect material removal from the working layers. The direction of the drives of the grinding apparatus is changed at least twice during trimming.
    Type: Grant
    Filed: February 20, 2014
    Date of Patent: March 24, 2015
    Assignee: Siltronic AG
    Inventors: Georg Pietsch, Michael Kerstan
  • Patent number: 8974267
    Abstract: An insert carrier is configured to receive at least one semiconductor wafer for double-side processing of the wafer between two working disks of a lapping, grinding or polishing process. The insert carrier includes a core of a first material that has a first surface and a second surface, and at least one opening configured to receive a semiconductor wafer. A coating at least partially covers the first and second surfaces of the core. The coating includes a surface remote from the core that includes a structuring including elevations and depressions. A correlation length of the elevations and depressions is in a range of 0.5 mm to 25 mm and an aspect ratio of the structuring is in a range of 0.0004 to 0.4.
    Type: Grant
    Filed: December 6, 2011
    Date of Patent: March 10, 2015
    Assignee: Siltronic AG
    Inventors: Georg Pietsch, Michael Kerstan
  • Patent number: 8911281
    Abstract: A method for trimming two working layers including bonded abrasive applied on mutually facing sides of an upper and a lower working disk of a grinding apparatus configured for simultaneous double-side processing of flat workpiece includes providing the grinding apparatus including the upper and lower working disks and providing at least one carrier including an outer toothing. The upper and lower working disks are rotated. The carrier is moved between the rotating working disks using a rolling apparatus and the outer toothing on cycloidal paths relative to working layers of the working disks. Loose abrasives are added to a working gap formed between the working layers. A carrier, without workpieces inserted therein, is moved in the working gap so as to effect material removal from the working layers.
    Type: Grant
    Filed: July 13, 2011
    Date of Patent: December 16, 2014
    Assignee: Siltronic AG
    Inventors: Georg Pietsch, Michael Kerstan
  • Publication number: 20140170942
    Abstract: A trimming apparatus for trimming two working layers including bonded abrasive applied on mutually facing sides of an upper and a lower working disk of a grinding apparatus configured for simultaneous double-side processing of flat workpiece includes a trimming disk, a plurality of trimming bodies and an outer toothing, where the trimming bodies are configured to release abrasive substances upon contract with the working layers so as to effect material removal from the working layers. At least 80% of the area of the trimming bodies configured to come into contact with the working layers is arranged within a ring-shaped region on the trimming disk. The width of the ring-shaped region is between 1-25% of the diameters of the trimming disk and the area of the trimming bodies which comes into contact with the working layers occupies 20-90% of the total area of the ring-shaped region.
    Type: Application
    Filed: February 25, 2014
    Publication date: June 19, 2014
    Applicant: Siltronic AG
    Inventors: Georg Pietsch, Michael Kerstan
  • Publication number: 20140170939
    Abstract: A method for trimming two working layers including bonded abrasive applied on mutually facing sides of an upper and a lower working disk of a grinding apparatus configured for simultaneous double-side processing of flat workpiece includes providing at least one trimming apparatus including a trimming disk, a plurality of trimming bodies and an outer toothing. The upper and lower working disks are rotated. The trimming apparatus is moved between the rotating working disks using a rolling apparatus and the outer toothing on cycloidal paths relative to working layers of the working disks. The working layers and the trimming body are brought into contact so as to release abrasive substances from the trimming bodies and so as to effect material removal from the working layers. The direction of the drives of the grinding apparatus is changed at least twice during trimming.
    Type: Application
    Filed: February 20, 2014
    Publication date: June 19, 2014
    Applicant: Siltronic AG
    Inventors: Georg Pietsch, Michael Kerstan
  • Patent number: 8685270
    Abstract: A method for producing a semiconductor wafer sliced from a single crystal includes rounding an edge using a grinding disk containing abrasives with an average grain size of 20.0-60.0 ?m. A first simultaneous double-side material-removing process is performed wherein the semiconductor wafers are processed between two rotating ring-shaped working disks, each working disk having a working layer containing abrasives having an average grain size of 5.0-20.0 ?m, wherein the semiconductor wafer is placed in a cutout in one of a plurality of carriers rotatable by a rolling apparatus such that the semiconductor wafer lies in a freely movable manner in the carrier and the wafer is movable on a cycloidal trajectory. A second simultaneous double-side material-removing process is performed including processing the semiconductor wafers between two rotating ring-shaped working disks, each working disk having a working layer containing abrasives having an average grain size of 0.5-15.0 ?m.
    Type: Grant
    Filed: October 12, 2010
    Date of Patent: April 1, 2014
    Assignee: Siltronic AG
    Inventors: Juergen Schwandner, Thomas Buschhardt, Diego Feijoo, Michael Kerstan, Georg Pietsch, Guenter Schwab
  • Patent number: 8529315
    Abstract: A method of producing a semiconductor wafer includes a plurality of steps carried out in the following order. Simultaneous double-side material-removal processing is carried out on a semiconductor wafer sliced from a single crystal by processing the semiconductor wafer between two rotating ring-shaped working disks. Each working disk includes first abrasives having an average grain size in a range of 5.0 to 20.0 ?m. Both sides of the semiconductor wafer are treated with an alkaline medium. Grinding of the front and rear sides of the semiconductor wafer is carried out. For the grinding of each side a first side is held using a wafer holder and the other side is processed using a grinding tool. The grinding tool includes second abrasives having an average grain size that is smaller than the average grain size of the first abrasives and having an average grain size being in a range of 1.0 to 10.0 ?m.
    Type: Grant
    Filed: January 20, 2011
    Date of Patent: September 10, 2013
    Assignee: Siltronic AG
    Inventors: Juergen Schwandner, Michael Kerstan
  • Patent number: 8512099
    Abstract: A device for double-sided processing of flat workpieces has upper and lower working discs forming between them a working gap containing a carrier disc with cutout(s) for workpiece(s), the carrier disc having circumferential teeth by means of which it rolls on an inner and an outer gear wheel or pin ring, wherein the gear wheels or pin rings have a multiplicity of gear or pin arrangements which engage the teeth of the carrier discs during rolling, at least one of the pin arrangements having a guide which delimits movement of the margin of the carrier disc in at least one axial direction, the guide formed by a circumferential shoulder or a circumferential groove.
    Type: Grant
    Filed: October 19, 2009
    Date of Patent: August 20, 2013
    Assignees: Siltronic AG, Peter Wolters GmbH
    Inventors: Michael Kerstan, Georg Pietsch, Frank Runkel, Conrad von Bechtolsheim, Helge Moeller
  • Publication number: 20120190277
    Abstract: An insert carrier is configured to receive at least one semiconductor wafer for double-side processing of the wafer between two working disks of a lapping, grinding or polishing process. The insert carrier includes a core of a first material that has a first surface and a second surface, and at least one opening configured to receive a semiconductor wafer. A coating at least partially covers the first and second surfaces of the core. The coating includes a surface remote from the core that includes a structuring including elevations and depressions. A correlation length of the elevations and depressions is in a range of 0.5 mm to 25 mm and an aspect ratio of the structuring is in a range of 0.0004 to 0.4.
    Type: Application
    Filed: December 6, 2011
    Publication date: July 26, 2012
    Applicant: SILTRONIC AG
    Inventors: Georg Pietsch, Michael Kerstan
  • Patent number: 8113913
    Abstract: Simultaneous double-side grinding of a plurality of semiconductor wafers involves positioning each wafer freely in a cutout of one of plural carriers which rotate on a cycloidal trajectory, wherein the wafers are machined between two rotating ring-shaped working disks, each disk having a working layer of bonded abrasive, wherein the form of the working gap between working layers is determined during grinding and the form of the working area of at least one disk is altered such that the gap has a predetermined form. The wafers, during machining, may temporarily overhang the gap. The carrier is optionally composed only of a first material, or is completely or partly coated with the first material such that during machining only the first material contacts the working layer, and the first material does not reduce the machining ability of the working layer.
    Type: Grant
    Filed: March 14, 2008
    Date of Patent: February 14, 2012
    Assignees: Siltronic AG, Peter Wolters GmbH
    Inventors: Georg Pietsch, Michael Kerstan, Heiko aus dem Spring
  • Publication number: 20120028546
    Abstract: A method for trimming two working layers including bonded abrasive applied on mutually facing sides of an upper and a lower working disk of a grinding apparatus configured for simultaneous double-side processing of flat workpiece includes providing the grinding apparatus including the upper and lower working disks and providing at least one carrier including an outer toothing. The upper and lower working disks are rotated. The carrier is moved between the rotating working disks using a rolling apparatus and the outer toothing on cycloidal paths relative to working layers of the working disks. Loose abrasives are added to a working gap formed between the working layers. A carrier, without workpieces inserted therein, is moved in the working gap so as to effect material removal from the working layers.
    Type: Application
    Filed: July 13, 2011
    Publication date: February 2, 2012
    Applicant: Siltronic AG
    Inventors: Georg Pietsch, Michael Kerstan
  • Publication number: 20110223841
    Abstract: A method of polishing a semiconductor wafer includes polishing a surface of the semiconductor wafer using a polishing pad while supplying a polishing agent slurry containing abrasives during a first step. The polishing pad is free of abrasives and includes a first surface that contacts the semiconductor wafer, the first surface having a surface structure including elevations. Supply of polishing agent slurry is subsequently ended and, in a second step, the surface of the semiconductor wafer is polished using the polishing pad while supplying a polishing agent solution having a pH value of at least 12 that is free of solids.
    Type: Application
    Filed: March 2, 2011
    Publication date: September 15, 2011
    Applicant: SILTRONIC AG
    Inventors: Juergen Schwandner, Michael Kerstan
  • Publication number: 20110183582
    Abstract: A method of producing a semiconductor wafer includes a plurality of steps carried out in the following order. Simultaneous double-side material-removal processing is carried out on a semiconductor wafer sliced from a single crystal by processing the semiconductor wafer between two rotating ring-shaped working disks. Each working disk includes first abrasives having an average grain size in a range of 5.0 to 20.0 ?m. Both sides of the semiconductor wafer are treated with an alkaline medium. Grinding of the front and rear sides of the semiconductor wafer is carried out. For the grinding of each side a first side is held using a wafer holder and the other side is processed using a grinding tool. The grinding tool includes second abrasives having an average grain size that is smaller than the average grain size of the first abrasives and having an average grain size being in a range of 1.0 to 10.0 ?m.
    Type: Application
    Filed: January 20, 2011
    Publication date: July 28, 2011
    Applicant: SILTRONIC AG
    Inventors: Juergen Schwandner, Michael Kerstan
  • Publication number: 20110097975
    Abstract: A method for producing a semiconductor wafer sliced from a single crystal includes rounding an edge using a grinding disk containing abrasives with an average grain size of 20.0-60.0 ?m. A first simultaneous double-side material-removing process is performed wherein the semiconductor wafers are processed between two rotating ring-shaped working disks, each working disk having a working layer containing abrasives having an average grain size of 5.0-20.0 ?m, wherein the semiconductor wafer is placed in a cutout in one of a plurality of carriers rotatable by a rolling apparatus such that the semiconductor wafer lies in a freely movable manner in the carrier and the wafer is movable on a cycloidal trajectory. A second simultaneous double-side material-removing process is performed including processing the semiconductor wafers between two rotating ring-shaped working disks, each working disk having a working layer containing abrasives having an average grain size of 0.5-15.0 ?m.
    Type: Application
    Filed: October 12, 2010
    Publication date: April 28, 2011
    Applicant: SILTRONIC AG
    Inventors: Juergen SCHWANDNER, Thomas BUSCHHARDT, Diego FEIJOO, Michael KERSTAN, Georg PIETSCH, Guenter SCHWAB
  • Patent number: 7867059
    Abstract: The invention relates to a process for producing a semiconductor wafer by double-side grinding of the semiconductor wafer, in which the semiconductor wafer is simultaneously ground on both sides, first by rough-grinding and then by finish-grinding, using a grinding tool. The semiconductor wafer, between the rough-grinding and the finish-grinding, remains positioned in the grinding machine, and the grinding tool continues to apply a substantially constant load during the transition from rough-grinding to finish-grinding. The invention also relates to an apparatus for carrying out the process and to a semiconductor wafer having a local flatness value on a front surface of less than 16 nm in a measurement window of 2 mm×2 mm area and of less than 40 nm in a measurement window of 10 mm×10 mm area.
    Type: Grant
    Filed: November 16, 2007
    Date of Patent: January 11, 2011
    Assignee: Siltronic AG
    Inventors: Georg Pietsch, Michael Kerstan, Werner Blaha
  • Patent number: 7815489
    Abstract: A method for the simultaneous double-side grinding of a plurality of semiconductor wafers, involves a process wherein each semiconductor wafer lies such that it is freely moveable in a cutout of one of a plurality of carriers caused to rotate by means of a rolling apparatus and is thereby moved on a cycloidal trajectory, wherein the semiconductor wafers are machined in material-removing fashion between two rotating working disks, wherein each working disk comprises a working layer containing bonded abrasive. The method according to the invention makes it possible, by means of specific kinematics, to produce extremely planar semiconductor wafers.
    Type: Grant
    Filed: July 9, 2007
    Date of Patent: October 19, 2010
    Assignees: Siltronic AG, Peter Wolters GmbH
    Inventors: Georg Pietsch, Michael Kerstan, Heiko aus dem Spring
  • Publication number: 20100099337
    Abstract: A device for double-sided processing of flat workpieces has upper and lower working discs forming between them a working gap containing a carrier disc with cutout(s) for workpiece(s), the carrier disc having circumferential teeth by means of which it rolls on an inner and an outer gear wheel or pin ring, wherein the gear wheels or pin rings have a multiplicity of gear or pin arrangements which engage the teeth of the carrier discs during rolling, at least one of the pin arrangements having a guide which delimits movement of the margin of the carrier disc in at least one axial direction, the guide formed by a circumferential shoulder or a circumferential groove.
    Type: Application
    Filed: October 19, 2009
    Publication date: April 22, 2010
    Applicants: SILTRONIC AG, PETER WOLTERS GMBH
    Inventors: Michael Kerstan, Georg Pietsch, Frank Runkel, Conrad von Bechtolsheim, Helge Moeller