The invention is concerned with a material which shows low absorption for UV radiation having a wavelength below 250 nm, low birefringence, high chemical resistance and high radiation resistance and which is therefore particularly usable for making optical components for microlithography. According to the invention the material consists of synthetically produced quartz crystallites which form a polycrystalline structure and have a mean grain size in the range between 500 nm and 30 .mu.m. The method according to the invention for making a blank from the material comprises providing granules consisting of synthetically produced quartz crystals having a mean grain size in the range between 500 nm and 30 .mu.m, and sintering the granules to obtain a blank of polycrystalline quartz.

 
Web www.patentalert.com

< Method for sour gas treatment

> Preparation of silver particles using thermoplastic polymers

> Reducible oxide based catalysts

~ 00594