Patent application number | Description | Published |
20090159816 | Method of testing optical materials by irradiating with high energy density radiation, optical materials selected by said method and uses thereof - An optical material for lithographic applications is selected from crystal materials by a testing method. The crystal materials are preferably quartz and/or alkali or alkaline earth halides, especially fluorides, or mixed crystals. The testing method includes three tests to measure irreversible radiation damage: 1) the optical material is irradiated with ultraviolet radiation at 193 nm and the non-intrinsic fluorescence intensity at 740 nm is measured; 2) the optical material is irradiated with high energy density laser light and a change in respective absorptions before and after irradiation at 385 nm is measured; and 3) the optical material is irradiated with an X-ray or radioactive source to form all possible color centers and a difference of respective surface integrals of corresponding absorption spectra in ultraviolet spectral and/or visible spectral regions is measured before and after irradiation. | 06-25-2009 |
20090176081 | Method and apparatus for making a highly uniform low-stress single crystal by drawing from a melt and uses of said crystal - The method of making uniform low-stress crystals includes immersing a seed crystal held at a temperature under its melting point in a melt in a crucible and drawing it from the melt. The crystal and/or melt are rotated relative to each other and a planar phase boundary surface is maintained between them by detecting a surface temperature of the melt and/or crystal and controlling temperature fluctuations by increasing or decreasing the rotation speed. The single crystals obtained by this method have a diameter ≧50 mm and no visible growth strips in a fishtail pattern when a 2-mm thick sample is observed between crossed polarizers. These crystals have an index of refraction uniformity Δn of <1 ppm and a stress birefringence of <1 nm/cm at 193 nm, so that optical elements suitable for DUV lithography can be made from them. | 07-09-2009 |
20090180948 | METHOD OF MAKING LARGE-VOLUME CaF2 SINGLE CRYSTALS FOR OPTICAL ELEMENTS WITH AN OPTIC AXIS PARALLEL TO THE (100)-OR (110)-CRYSTAL AXIS AND CaF2 SINGLE CRYSTAL MADE THEREBY - The method of making a single crystal, especially a CaF | 07-16-2009 |
20090279068 | Device and process for increasing the light transmission of optical elements for light having a wavelength close to the absorption edge - 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. | 11-12-2009 |
20100111820 | METHOD OF DETERMINING LASER STABILITIES OF OPTICAL MATERIAL, CRYSTALS OBTAINED WITH SAID METHOD, AND USES OF SAID CRYSTALS - A method of selecting suitable laser-stable optical material for making an optical element, especially for transmission at wavelengths under 200 nm, is described. It includes a first pre-irradiation to produce radiation damage, subsequent excitation of induced fluorescence with light at between 350 to 700 nm at least ten minutes after the first pre-irradiation and measurement of induced fluorescence intensities at one or more wavelengths between 550 nm and 810 nm. After the fluorescence intensity measurement a second pre-irradiation is performed with an at least 1000-fold higher energy than in the first pre-irradiation and then induced fluorescence intensities are again measured to determine the increase in the fluorescence intensities. The materials determined to have suitable laser stability are used for making lenses, prisms, light-conducting rods, optical windows and optical devices for DUV lithography, especially steppers and excimer lasers, integrated circuits, computer chips as well as other electronic devices. | 05-06-2010 |
20100139550 | CRUCIBLE FOR PROCESSING A HIGH-MELTING MATERIAL AND METHOD OF PROCESSING SAID MATERIAL IN SAID CRUCIBLE - The crucible for receiving a melt of a high-melting material has a refractory metal layer that has a melting point of at least 1800° C., which covers a part of the surface of the crucible that would otherwise come in contact with the melt. The refractory metal preferably has a thickness of less than 1 mm. It is either a coating deposited on the surface of the crucible or is a loosely connected foil applied to the surface of the crucible. | 06-10-2010 |
20110076217 | PROCESS FOR GROWING RARE EARTH ALUMINUM OR GALLIUM GARNET CRYSTALS FROM A FLUORIDE-CONTAINING MELT AND OPTICAL ELEMENTS AND SCINTILLATION MADE THEREFROM - The process for growing a rare earth aluminum or gallium garnet crystal from a melt includes melting an aluminum or gallium garnet of at least one rare earth, preferably Lu or Y, or a mixture of oxides of formula Me | 03-31-2011 |
20110084210 | Process for producing a particularly strong scintillation material, a crystal obtained by said process and uses thereof - A large-volume scintillation crystal affording a high scintillation yield and having high mechanical strength is obtained by growing a crystal from a melt containing strontium iodide, barium iodide or a mixture thereof and by doping with an activator. To this end, the melt is enclosed in a closed volume. Before and/or during the growing, the melt is in diffusion-permitting connection, via the enclosed volume, with an oxygen getter which sets a constant oxygen potential in the closed volume and the melt. Such a scintillation crystal is suitable for detecting UV-, gamma-, beta-, alpha- and/or positron radiation. | 04-14-2011 |
20110084233 | Scintillation materials in single crystal or polycrystalline form with improved properties, especially light yield and strain birefringence - The scintillation material is a compound of the general formula LnX | 04-14-2011 |
20110084234 | Scintillation materials of low oxygen content and process for producing same - The scintillation material has a maximum oxygen content of 2,500 ppm and is a compound of formula LnX | 04-14-2011 |
20110085957 | Process for producing scintillation materials of low strain birefringence and high refractive index uniformity - The process produces a scintillation material of formula LnX | 04-14-2011 |
20110130266 | METHOD AND APPARATUS FOR MAKING A HIGHLY UNIFORM LOW-STRESS SINGLE CRYSTAL BY DRAWING FROM A MELT AND USES OF SAID CRYSTAL - The method of making uniform low-stress crystals includes immersing a seed crystal held at a temperature under its melting point in a melt in a crucible and drawing it from the melt. The crystal and/or melt are rotated relative to each other and a planar phase boundary surface is maintained between them by detecting a surface temperature of the melt and/or crystal and controlling temperature fluctuations by increasing or decreasing the rotation speed. A low-stress crystal of formula: (A | 06-02-2011 |