Schott Ag

Hellma Materials Gmbh & Co. Kg

Schott Glas

Hellma Materials Gmbh

Lutz Parthier

Gunther Wehrhan

Joerg Staeblein

Frank-Thomas Lentes

Gordon Von Der Goenna

Ulrich Peuchert

Andreas Ortner

Fabian Wagner

Andreas Roters

Matthias Jotz

Regina Martin

Joerg Kandler

Florian Resch

Laura Brückbauer

Burkhard Speit

Jochen Alkemper

Martin Letz

Markus Heiss-Chouquet

Andreas Menzel

Ute Natura

Matthias Mueller

Daniel Rytz

Lothar Ackermann

Vanessa Gläßer

Christian Kusch

Klaus Dupre

Lars Ortmann

Karin Poehl

Axel Engel

Clemens Kunisch

Klaus Petermann

Vanessa Hiller

Konrad Knapp

Johann-Christoph Von Saldern

Andreas Weisleder

Christoph Seitz

Hans-Joerg Axmann

Dietmar Keutel

Markus Heiß-Choquet

Thomas Kaufhold

Michael Selle

Erik Foerster

Erik Förster

A method includes: providing a plate-like glass element having side faces and an ultrashort pulse laser having a laser beam; directing the laser beam onto one of the side faces; concentrating the laser beam by focusing optics to form an elongated focus in the glass element; producing a filament-shaped flaw in a volume of the glass element by a radiated-in energy of the laser beam, a longitudinal direction of which runs transverse to one of the side faces, and the ultrashort pulse laser radiates in a pulse or a pulse packet having at least two successive laser pulses to produce the filament-shaped flaw; widening the filament-shaped flaw to form a channel by exposing the glass element to an etching including an etching medium which removes glass at a rate of less than 8 μm per hour; and introducing rounded, hemispherical depressions in a wall of the channel by the etching.

Structured plate-like glass element and process for the production thereof

A plate-like glass element includes a pair of opposite side faces and an opening having a transverse dimension of at least 200 μm. The opening is delimited by an edge. The edge has a plurality of rounded, substantially hemispherical depressions that adjoin one another. The plurality of rounded, substantially hemispherical depressions having abutting concave roundings which form ridges.

A plate-like glass element including a pair of opposite side faces and at least one channel introduced into the glass of the glass element. The at least one channel joins the side faces and opens into the side faces. The at least one channel has a rounded wall and a transverse dimension of less than 100 &#x3bc;m. The at least one channel extends in a longitudinal direction that runs transverse to the side faces. The rounded wall of the at least one channel has a plurality of rounded, substantially hemispherical depressions.

The scintillation material has a maximum oxygen content of 2,500 ppm and is a compound of formula LnXor LnX:D, wherein Ln is at least one rare earth element, X is F, Cl, Br, or I; and D is at least one cationic dopant of one or more of the elements Y, Zr, Pd, Hf and Bi and, if present, is present in an amount of 10 ppm to 10,000 ppm. The process of making the scintillation material includes optionally mixing the compound of the formula LnXwith the at least one cationic dopant, heating the compound or the mixture so obtained to a melting temperature to form a melt, adding one or more carbon halides and then cooling the melt to form a crystal or crystalline structure. The maximum oxygen content of the scintillation material is preferably 1000 ppm.

Scintillation materials of low oxygen content and process for producing same

The method produces low-stress, large-volume crystals with low birefringence and uniform index of refraction. The method includes growing the crystal with larger than desired dimensions including diameter and height from a melt; cooling and tempering the crystal with the larger than desired dimensions and after the cooling and tempering removing edge regions of the crystal with the larger than desired dimensions so that a diameter reduction and a height reduction of at least five percent occurs respectively and so that the crystal has the desired dimensions of diameter and height. No further tempering takes place after removing of the edge regions.

Method for making low-stress large-volume crystals with reduced stress birefringence and more uniform refractive index and crystals made thereby

Homogeneity residuals of the refractive index have a strong influence on the performance of lithography tools for both 193 and 157 nm application wavelengths. By systematic investigations of various defects in the real structure of CaFcrystals, the origin of homogeneity residuals can be shown. Based on a quantitative analysis we define limiting values for the individual defects which can be either tolerated or controlled by optimized process steps, e.g. annealing. These correlations were carried out for all three relevant main crystal lattice orientations of CaFblanks. In conclusion we achieved a strong improvement of the critical parameters of both refractive index homogeneity and striae for large size lens blanks up to 270 mm diameter.

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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 &#x3c;100&#x3e; or &#x3c;111&#x3e; 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&#xb0;, 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 &#x3c;100&#x3e; or &#x3c;111&#x3e; 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. Preferably the device is used in DUV lithography, in particular in steppers and excimer lasers, as well as for the production of integrated circuits, computer chips as well as electronic devices such as computers, and other devices that comprise chip-type integrated circuits, as well as for flat screens.

Arrangement and method for preventing the depolarization of linear-polarized light during the transmission of light through crystals

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 &#x2267;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 &#x394;n of &#x3c;1 ppm and a stress birefringence of &#x3c;1 nm/cm at 193 nm, so that optical elements suitable for DUV lithography can be made from them.

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 a single crystal, especially a CaFsingle crystal, includes tempering, in which the crystal is heated at &#x3c;18 K/h to a temperature of 1000&#xb0; C. to 1350&#xb0; C. and held at this temperature for at least 65 hours with maximum temperature differences within the crystal of &#x3c;0.2 K. Subsequently the crystal is cooled with a cooling rate of at maximum 0.5 K/h above a limiting temperature between 900&#xb0; C. to 600&#xb0; C. and then further below this limiting temperature at maximum 3 K/h. The obtained CaFcrystals have refractive index uniformity &#x3c;0.025&#xd7;10(RMS) in a (111)-, (100)- or (110)-direction and a stress birefringence of less than 2.5 nm/cm (PV) and/or a stress birefringence of less than 1 nm/cm (RMS) in the (100)- or (110)-direction. In the (111)-direction the stress birefringence is &#x3c;0.5 nm/cm (PV) and/or the stress birefringence is &#x3c;0.15 nm/cm (RMS).

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.

Method of testing optical materials by irradiating with high energy density radiation, optical materials selected by said method and uses thereof

The method determines laser stability of an optical material, which is suitable for making an optical element through which high-energy light passes. The method includes pre-irradiation to produce radiation damage and measurement of the resulting induced non-intrinsic fluorescence. The method is distinguished by excitation of induced fluorescence immediately after pre-irradiation and after at least ten minutes after pre-irradiation with light of a wavelength between 350 and 810 nm, and measurement and quantitative evaluation of fluorescence intensities at wavelengths between 550 nm and 810 nm. Especially laser-stable optical materials, particularly CaFcrystals, have a normalized difference (Z) of the fluorescence intensities measured at a first time immediately after pre-irradiation and at a second time at least ten minutes after the pre-irradiation, as calculated by the following equation (1):=()&#x2003;&#x2003;(1),which is less than 0.3.

Method of determining laser stabilities of optical materials, crystals selected according to said method, and uses of said selected crystals

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 YAlO, LuAlO, CaAlSiO, KNaAlF, KNaScF, KLiAlFand/or NaAlLiF, (Mg, Zn)AlO, CaAlO, CaBOand/or LiAlO, BaZrOand/or CaCeO. 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.

Method for making optical elements for microlithography, the lens systems obtained by the method and their uses

Single crystals with low scattering, small refractive index differences and few small angle grain boundaries have a bi-directional scattering distribution function value (BSDF) of less than 1.5*10or 5*10.

The method determines the extent of irreversible radiation damage of an optical material. The method includes the following three tests to determine the extent of irreversible radiation damage: 1) the optical material is irradiated with ultraviolet radiation at a wavelength of 193 nm and the non-intrinsic fluorescence intensity at a wavelength of 740 nm is measured; 2) the optical material is irradiated with high energy laser light and a change in respective absorptions at a wavelength of 385 nm is determined before and after irradiation; and 3) the optical material is irradiated with an energetic radiation 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.

Method for determination of irreversible radiation damage of optical materials

The method provides a uniform low-stress single crystal in a predetermined crystal orientation. The method of making it includes immersing a single crystal held at a temperature under its melting point in a melt of crystal raw material and drawing it from the melt to grow the crystal. The crystal and/or melt are rotated relative to each other during the crystal growth. A planar phase boundary surface is maintained by detecting at least one characteristic surface temperature in an interior of a crucible containing the melt and controlling temperature fluctuations by increasing or decreasing the rotation speed when they occur. The single crystals obtained by this method have a diameter of at least 50 mm and no visible growth strips in a fishtail pattern when a 2-mm thick sample is observed between crossed polarizers. Optical elements suitable for DUV lithography can be made from these crystals.

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Kleinmachnow, Germany

Lutz Parthier