Patents by Inventor Martin Letz

Martin Letz 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).

  • Publication number: 20130120193
    Abstract: A glass-ceramic which is particularly suitable as dielectric for use in the high-frequency range, in particular as dielectric resonator, as electronic frequency filter element or as antenna element is disclosed. The glass-ceramic has at least the following constituents (in mol % on an oxide basis): 5-50% of SiO2, 0-20% of Al2O3, 0-25% of B2O3, 0-25% of BaO, 10-60% of TiO2, 5-35% of Re2O3, where Ba can be partly replaced by Sr, Ca, Mg, where Re is a lanthanide or yttrium and where Ti can be partly replaced by Zr, Hf, Y, Nb, V, Ta.
    Type: Application
    Filed: November 16, 2011
    Publication date: May 16, 2013
    Applicant: SCHOTT AG
    Inventors: Bernd Hoppe, Michael Kluge, Stephan Knoener, Martin Letz, Bernd Ruedinger, Daniela Seiler
  • Patent number: 8263509
    Abstract: A process for the production of a glass-ceramic comprises the following steps: a) providing a mixture comprising at least SiO2, Al2O3, BaO and TiO2, b) melting the mixture in order to produce a glass phase, c) cooling the glass phase, and d) ceramicizing the glass phase. In the process, the glass phase is heated over the course of at most 5 minutes, preferably over the course of at most 3 minutes, to a temperature in the region of the crystallization temperature of Ba1-xZ1xTi1-yZ2yO3, whereby Z1 is an element selected from the group consisting of Sr, Ca, Ce, Pb, La and Sm, whereby Z2 is an element selected from the group consisting of Zr, Hf, Nb, V, Y, Sc and Ta, and whereby x and y are each independently of one another 0?x,y?0.5, preferably 0?x,y?0.1, but substantially below the crystallization temperature of Ba[Al2Si2O8].
    Type: Grant
    Filed: June 4, 2010
    Date of Patent: September 11, 2012
    Assignee: Schott AG
    Inventors: Bernd Hoppe, Daniela Seiler, Bernd Ruedinger, Ina Mitra, Maria-Louisa Reich, Martin Letz, Michael Kluge
  • Patent number: 8141387
    Abstract: The process of making the glass-ceramic includes ceramicizing a starting glass at a heating or cooling rate during the ceramicization of at least 10 K/min, so that the glass-ceramic contains at least 50% by volume of ferroelectric crystallites with a maximum diameter of from 20 to 100 nm and not more than 10% by volume of nonferroelectric crystallitesis. The glass ceramic produced by the process contains no pores or not more than 0.01% by volume of the pores and a value of e?·V2max of the glass-ceramic is at least 20 (MV/cm)2, wherein e? is the dielectric constant at 1 kHz and Vmax is the breakdown voltage per unit thickness. The ferroelectric crystallites preferably have a perovskite structure and are composed of substantially pure or doped BaTiO3 and/or BaTi2O5.
    Type: Grant
    Filed: February 25, 2009
    Date of Patent: March 27, 2012
    Assignee: Schott AG
    Inventors: Martin Letz, Mark J. Davis, Bernd Ruedinger, Bernd Hoppe, Bianca Schreder, Maria-Louisa Aigner, Daniela Seiler
  • Publication number: 20110317329
    Abstract: A capacitor having a dielectric consisting of a glass layer with an alkali metal oxide content of at most 2 wt % and a thickness of at most 50 ?m is provided. The capacitor includes at least two metal layers which are separated by the glass layer. The glass layer is preferably produced by a down-draw method or by an overflow down-draw fusion method.
    Type: Application
    Filed: August 9, 2011
    Publication date: December 29, 2011
    Inventors: Martin Letz, Hans-Heinrich Gundelach, Holger Wegener
  • Patent number: 8039407
    Abstract: The invention provides a method for producing a glass ceramic comprising the steps of melting a starting glass that is free from alkali, except for incidental contamination, and that contains at least one garnet-forming agent and at least one oxide of a lanthanoid; grinding the starting glass to produce a glass frit; molding by pressing and sintering the glass frit until at least one garnet phase containing lanthanoids is formed. A glass ceramic produced in this way may contain 5-50% by weight of SiO2, 5-50% by weight of Al2O3 and 10-80% by weight of at least one oxide selected from the group formed by Y2O3, Lu2O3, Sc2O3, Gd2O3, Yb2O3, Ce2O3, as well as 0.1-30% by weight of at least one oxide selected from the group formed by B2O3, Th2O3, and oxides of the lanthanoids, except Lu2O3, Gd2O3, Yb2O3, Ce2O3. Such a glass ceramic is suited especially for down conversion of excitation radiation in the blue and in the UV region of the spectrum.
    Type: Grant
    Filed: November 18, 2010
    Date of Patent: October 18, 2011
    Assignee: Schott AG
    Inventors: Karine Seneschal-Merz, Bernd Hoppe, Dirk Sprenger, Martin Letz, Thilo Zachau, Friedrich Siebers
  • Patent number: 7958746
    Abstract: The invention proposes a method for producing glass ceramics which is particularly well suited as light conversion material, especially for down conversion. One initially produces a starting glass, containing (on an oxide basis) 5-50% by weight of SiO2, 5-50% by weight of Al2O3 and 10-80% by weight of at least one oxide selected from the from the group formed by Y2O3, Lu2O3, Sc2O3, Gd2O3, Yb2O3, Ce2O3, as well as 0.1-30% by weight of at least one oxide selected from the group formed by B2O3, Th2O3, and oxides of the lanthanoids, except Lu2O3, Gd2O3, Yb2O3, Ce2O3. Thereafter, the material is heated up for ceramization at a heating rate of at least 100 K/min to a temperature in the range of between 1000° C. to 1400° C. until crystallites are formed that contain a garnet phase. Thereafter, the material is cooled down to room temperature. Alternatively, controlled cooling-down from the molten state is possible.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: June 14, 2011
    Assignee: Schott AG
    Inventors: Karine Seneschal-Merz, Bernd Hoppe, Dirk Sprenger, Friedrich Siebers, Martin Letz, Thilo Zachau
  • Patent number: 7910505
    Abstract: The invention provides a method for producing a glass ceramic comprising the steps of melting a starting glass that is free from alkali, except for incidental contamination, and that contains at least one garnet-forming agent and at least one oxide of a lanthanoid; grinding the starting glass to produce a glass frit; molding by pressing and sintering the glass frit until at least one garnet phase containing lanthanoids is formed. A glass ceramic produced in this way may contain 5-50 % by weight of SiO2, 5-50 % by weight of Al2O3 and 10-80 % by weight of at least one oxide selected from the group formed by Y2O3, Lu2O3, Sc2O3, Gd2O3, Yb2O3, Ce2O3, as well as 0.1-30% by weight of at least one oxide selected from the group formed by B2O3, Th2O3, and oxides of the lanthanoids, except Lu2O3, Gd2O3, Yb2O3, Ce2O3. Such a glass ceramic is suited especially for down conversion of excitation radiation in the blue and in the UV region of the spectrum.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: March 22, 2011
    Assignee: Schott AG
    Inventors: Karine Seneschal-Merz, Bernd Hoppe, Dirk Sprenger, Martin Letz, Thilo Zachau, Friedrich Siebers
  • Publication number: 20110062393
    Abstract: The invention provides a method for producing a glass ceramic comprising the steps of melting a starting glass that is free from alkali, except for incidental contamination, and that contains at least one garnet-forming agent and at least one oxide of a lanthanoid; grinding the starting glass to produce a glass frit; molding by pressing and sintering the glass frit until at least one garnet phase containing lanthanoids is formed. A glass ceramic produced in this way may contain 5-50% by weight of SiO2, 5-50% by weight of Al2O3 and 10-80% by weight of at least one oxide selected from the group formed by Y2O3, Lu2O3, Sc2O3, Gd2O3, Yb2O3, Ce2O3, as well as 0.1-30% by weight of at least one oxide selected from the group formed by B2O3, Th2O3, and oxides of the lanthanoids, except Lu2O3, Gd2O3, Yb2O3, Ce2O3. Such a glass ceramic is suited especially for down conversion of excitation radiation in the blue and in the UV region of the spectrum.
    Type: Application
    Filed: November 18, 2010
    Publication date: March 17, 2011
    Inventors: Karine Seneschal-Merz, Bernd Hoppe, Dirk Sprenger, Martin Letz, Thilo Zachau, Friedrich Siebers
  • Publication number: 20110028298
    Abstract: A process for the production of a glass-ceramic comprises the following steps: a) providing a mixture comprising at least SiO2, Al2O3, BaO and TiO2, b) melting the mixture in order to produce a glass phase, c) cooling the glass phase, and d) ceramicizing the glass phase. In the process, the glass phase is heated over the course of at most 5 minutes, preferably over the course of at most 3 minutes, to a temperature in the region of the crystallization temperature of Ba1-xZ1xTi1-yZ2yO3, whereby Z1 is an element selected from the group consisting of Sr, Ca, Ce, Pb, La and Sm, whereby Z2 is an element selected from the group consisting of Zr, Hf, Nb, V, Y, Sc and Ta, and whereby x and y are each independently of one another 0?x,y?0.5, preferably 0?x,y?0.1, but substantially below the crystallization temperature of Ba[Al2Si2O8].
    Type: Application
    Filed: June 4, 2010
    Publication date: February 3, 2011
    Inventors: Bernd HOPPE, Daniela Seiler, Bernd Ruedinger, Ina Mitra, Maria-Louisa Reich, Martin Letz, Michael Kluge
  • Patent number: 7873084
    Abstract: A process and a device is described to avoid the depolarization of linear-polarized light during the transmission of light through crystals exhibiting a {111} or {100} crystal plane, respectively, and a <100> or <111> crystal axis, respectively. The device is characterized in that the linear-polarized light meets the surface of the crystals in an angle of 45-75°, whereby the surface is formed by the {111} or the {100} plane. The crystal is arranged in such a way that upon entering the crystal, the light spreads along the <100> or <111> crystal axis, respectively, as parallel as possible, and/or that the device comprises a unit for temperature equalization to avoid a thermal gradient in the crystal.
    Type: Grant
    Filed: October 18, 2007
    Date of Patent: January 18, 2011
    Assignee: Hellma Materials GmbH & Co. KG
    Inventors: Ute Natura, Martin Letz, Lutz Parthier
  • Patent number: 7799444
    Abstract: The invention describes a glass and a glass-ceramic which at least includes the constituents SiO2, Al2O3 and Y2O3 and is preferably doped with rare earth ions. The weight ratio between the weight of Y2O3 and the total weight of SiO2, Al2O3 and Y2O3 is at least 0.2, preferably at least 0.4 or more. The rare earth ions can preferably be incorporated in crystal phases which are precipitated out of glass with a high yttrium content.
    Type: Grant
    Filed: September 27, 2005
    Date of Patent: September 21, 2010
    Assignee: Schott AG
    Inventors: Ulrich Peuchert, Thilo Zachau, Martin Letz, Joseph S. Hayden, Carol Click, Karine Seneschal, Axel Engel
  • Patent number: 7751123
    Abstract: The refractive, transmissive or diffractive optical elements are made from a ceramic containing one or more oxides of the type X2O3, which is transmissive for visible light and/or for infrared radiation and which has a cubic crystal structure analogous to that of Y2O3. In preferred embodiments X is Y, Sc, In, or a lanthanide element, namely La to Lu, and in particular is Lu, Yb, Gd, or La. Also mixtures of oxides of the type X2O3 with oxides having different stoichiometries, such as HfO2 and/or ZrO2, may be present, as long as the cubic structure of the ceramic is maintained.
    Type: Grant
    Filed: June 13, 2007
    Date of Patent: July 6, 2010
    Assignee: Schott AG
    Inventors: Jose Zimmer, Ulrich Peuchert, Jochen Alkemper, Martin Letz, Steffen Reichel, Yoshio Okano, Yvonne Menke
  • Patent number: 7679806
    Abstract: The optical elements for ultraviolet radiation, especially for microlithography, are made from cubic granet, cubic spinel, cubic perovskite and/or cubic M(II)- as well as M(IV)-oxides. The optical elements are made from suitable crystals of Y3Al5O12, Lu3Al5O12, Ca3Al2Si3O12, K2NaAlF6, K2NaScF6, K2LiAlF6 and/or Na3Al2Li3F12, (Mg, Zn)Al2O4, CaAl2O4, CaB2O4 and/or LiAl5O8, BaZrO3 and/or CaCeO3. A front lens used in immersion optics for microlithography at wavelengths under 200 nm is an example of a preferred optical element of the present invention.
    Type: Grant
    Filed: March 7, 2006
    Date of Patent: March 16, 2010
    Assignee: Schott AG
    Inventors: Gunther Wehrhan, Regina Martin, Lutz Parthier, Joerg Staeblein, Martin Letz, Jochen Alkemper, Konrad Knapp, Klaus Petermann
  • Publication number: 20100045164
    Abstract: The invention concerns a glass composition for a glass body of an illuminating means with external electrodes, wherein the quotient of the loss angle (tan ?[10?4]) and the dielectric constant (??) amounts to tan ?[10?4]/??<5, i.e., tan ?/??<5×10?4). In this way, the total power loss of the illuminating means with external electrodes can be minimized in a targeted manner by means of the glass properties.
    Type: Application
    Filed: December 29, 2005
    Publication date: February 25, 2010
    Inventors: Joerg Fechner, Martin Letz, Steffen Reichel, Franz Ott, Brigitte Hueber
  • Publication number: 20090279068
    Abstract: Described are a process and a device for increasing the light transmission of an optical element for light of a wavelength that is close to the absorption edge of the material constituting the optical element. The process involves cooling the optical element. The process is especially well suited for microlithography with immersion objectives. A preferred device is, for example, a stepper for producing electronic components.
    Type: Application
    Filed: May 7, 2009
    Publication date: November 12, 2009
    Inventors: Martin Letz, Lutz Parthier
  • Publication number: 20090215605
    Abstract: The process of making the glass-ceramic includes ceramicizing a starting glass at a heating or cooling rate during the ceramicization of at least 10 K/min, so that the glass-ceramic contains at least 50% by volume of ferroelectric crystallites with a maximum diameter of from 20 to 100 nm and not more than 10% by volume of nonferroelectric crystallitesis. The glass ceramic produced by the process contains no pores or not more than 0.01% by volume of the pores and a value of e?·V2max of the glass-ceramic is at least 20 (MV/cm)2, wherein e? is the dielectric constant at 1 kHz and Vmax is the breakdown voltage per unit thickness. The ferroelectric crystallites preferably have a perovskite structure and are composed of substantially pure or doped BaTiO3 and/or BaTi2O5.
    Type: Application
    Filed: February 25, 2009
    Publication date: August 27, 2009
    Inventors: Martin Letz, Mark J. Davis, Bernd Ruedinger, Bernd Hoppe, Bianca Schreder, Maria-Louisa Aigner, Daniela Seiler
  • Publication number: 20090158778
    Abstract: The glass fiber for an optical amplifier has a glass core, a first glass cladding, and a second glass cladding. The core has a composition, in mol %, of Bi2O3, 30-60; SiO2, 0.5-40; B2O3, 0.5-40; Al2O3, 0-30; Ga2O3, 0-20; Ge2O3, 0-25; La2O3, 0-15; Nb2O5, 0-10; SnO2, 0-30; alkali metal oxides, 0-40; and Er2O3, 0.05-8. The process for making the glass fiber includes first making a preform consisting of the core and the first glass cladding by drawing from a double crucible. Then the second glass cladding is formed around the preform by a rod-in-tube process. The glass claddings have a composition that includes a transition metal compound as an absorbent.
    Type: Application
    Filed: March 6, 2009
    Publication date: June 25, 2009
    Inventors: Ulrich Peuchert, Ruediger Sprenhard, Martin Letz, Frank Buellesfeld
  • Patent number: 7515802
    Abstract: The glass fiber for an optical amplifier has a matrix glass core, a first glass cladding, and a second glass cladding. The matrix glass core has a composition, in mol %, of Bi2O3, 30-60; SiO2, 0.5-40; B2O3, 0.5-40; Al2O3, 0-30; Ga2O3, 0-20; Ge2O3, 0-25 ; La2O3, 0-15; Nb2O5, 0-10; SnO2, 0-30; alkali metal oxides, 0-40; and Er2O3, 0.05-8. The glass claddings have the same composition as the core, except that a transition metal compound is included as an absorbent. The refraction index of the matrix glass is > about 1.85, the refraction index of the first glass cladding is less than that of the core, and the refraction index of the second glass cladding is higher than that of the first.
    Type: Grant
    Filed: September 7, 2002
    Date of Patent: April 7, 2009
    Assignee: Schott AG
    Inventors: Ulrich Peuchert, Ruediger Sprenhard, Martin Letz, Frank Buellesfeld
  • Publication number: 20080145794
    Abstract: The present invention relates to a new class of compound useful as liquid for immersion lithography, said liquid comprising molecules so that said liquid is substantially transparent at a wavelength used for said liquid immersion lithography, wherein a degree of polarization of light, which is incident on a sample of said liquid in a forward direction and which is scattered in a direction perpendicular to said forward direction within a plane of scattering defined by said forward direction and said direction perpendicular to said forward direction, is larger than 0.9. Suited liquids are, for example, such comprising molecules transparent to UV radiation, wherein said molecules are high-symmetric molecules. Suited compounds are defined by A(R)4 wherein A is defined to be a 4-valent element and R is selected from —(C)n— and —(Si)n—, with n=1 to 10, wherein the remaining valences of the carbon or silica are saturated by one (or more) selected from hydrogen and a halogen.
    Type: Application
    Filed: February 21, 2008
    Publication date: June 19, 2008
    Inventors: Martin Letz, Konrad Knapp, Hauke Esemann, Andreas Voitsch
  • Publication number: 20080094701
    Abstract: A process and a device is described to avoid the depolarization of linear-polarized light during the transmission of light through crystals exhibiting a {111} or {100} crystal plane, respectively, and a <100> or <111> crystal axis, respectively. The device is characterized in that the linear-polarized light meets the surface of the crystals in an angle of 45-75°, whereby the surface is formed by the {111} or the {100} plane. The crystal is arranged in such a way that upon entering the crystal, the light spreads along the <100> or <111> crystal axis, respectively, as parallel as possible, and/or that the device comprises a unit for temperature equalization to avoid a thermal gradient in the crystal.
    Type: Application
    Filed: October 18, 2007
    Publication date: April 24, 2008
    Inventors: Ute Natura, Martin Letz, Lutz Parthier