Schott Ag

Schott Glas

Andreas Weisleder

Burkhard Speit

Lutz Parthier

Andreas Menzel

Gunther Wehrhan

Matthias Mueller

Joerg Staeblein

Joerg Kandler

Rainer Guett

A method for producing high-purity, large-volume monocrystals that are especially radiation-resistant and have low intrinsic birefringence. From a melt of crystalline raw material, with controlled cooling and solidification, a crystal is generated. As the crystalline raw material, shards and/or waste from already-grown crystals is used, and the re-used raw material In this way, crystals can be obtained which after tempering have a BSDF value of &#x3c;7&#xd7;10, an RMS homogeneity after the subtraction of 36 Zernike coefficients of &#x3c;15&#xd7;10, an SDR-RMS value in the 111 direction of &#x3c;0.2 nm/cm.

Production of high-purity, large-volume monocrystals that are especially radiation-resistant from crystal shards

The method for making a uniform, large-size single crystal of calcium fluoride includes placing a single precursor crystal of calcium fluoride in a tempering vessel provided with a cover; introducing calcium fluoride powder into the tempering vessel and subsequently heating the single precursor crystal, preferably in intimate contact with the calcium fluoride powder, in the tempering vessel together with the calcium fluoride powder for two or more hours at temperatures above 1150&deg; C. to temper the precursor crystal and thus form the uniform, large-scale single crystal of calcium fluoride. The uniform large-sized single crystals of calcium fluoride can be used to make improved lens, prism, light-conducting rod, optical window or other optical component for DUV photolithography, steppers, excimer lasers, wafers, computer chips and electronic devices containing the wafers and chips.

Methods for growing large-volume single crystals from calcium fluoride and their uses

Growing community of inventors

Tautenhain, Germany

Andreas Weisleder