Disclosed are barrier coatings for fused silica components used in semiconductor processing. In particular, the present disclosure concerns protective substrate-barrier coatings composed of corrosion-resilient metal compounds which provide superior resistance to erosion/corrosion when a coated substrate is subjected to the acidic environments at elevated temperatures typical for semiconductor processing.

A method for manufacturing an optical element out of glass comprises placing a blank made of glass on an annular contact face of a supporting body having a hollow cross section. The blank is heated on the supporting body in a cavity of a protective cap that is arranged in a furnace cavity, such that a temperature gradient is established in the blank in such a way that the blank is cooler inside than on an outside region. The blank is press molded to form the optical element.

The present disclosure relates to a method for manufacturing an optical element out of glass, wherein a blank made of glass is laid on an annular contact face of a supporting body having a hollow cross section, and is heated on the supporting body, in a cavity of a protective cap that is arranged in a furnace cavity, such that a temperature gradient is established in the blank in such a way that the blank is cooler inside than on an outside region, wherein the contact face is cooled by means of a cooling medium flowing through the supporting body, wherein following heating the glass blank is press molded to form the optical element.

Disclosed are barrier coatings for fused silica components used in semiconductor processing. In particular, the present disclosure concerns protective substrate-barrier coatings composed of corrosion-resilient metal compounds which provide superior resistance to erosion/corrosion when a coated substrate is subjected to the acidic environments at elevated temperatures typical for semiconductor processing.