UHP is the acronym for ultra high purity. The glass vacuum chambers of our plasma systems are UHP and can be made either of borosilicate glass or silica glass. The UHP option is now available for the following systems: Femto, Pico and Nano. Glass chambers are used in microwave systems and/or in applications where an ultra-pure surface is required. Regular stainless steel or aluminium chambers, like all metals in a plasma system, i.e. also the material to be treated, may sputter to a very minor degree. For most processes, this is completely irrelevant and can be disregarded. The aluminium components in the UHP system are coated with AL2O3.