Abstract: A quartz glass component for a reactor chamber, especially of a plasma etching device, comprises a substrate of a first quartz glass quality with an inner surface having an average roughness depth Ra of more than 1 &mgr;m, facing the inside of the reactor. To minimize particles in the reactor chamber, and to give the inner surface high adhesiveness for layers deposited on it and a long service life, a roughness zone is formed on the substrate by an open pore bubble layer made of a second quartz glass quality. The quartz glass component may be made by forming a blank from a granulate containing SiO2, and partial or complete vitrification of the blank by heating to a temperature above 1,000° C. During the forming of the inner surface of the blank, an additional constituent is added to the granulate containing siO2 in a roughness zone. The additional constituent reacts during the vitrification to release a gas, which forms a bubble layer during vitrification of the roughness zone.

Abstract: A quartz glass component for use in the manufacture of semiconductors is provided. It has a rough surface which is formed by irregular elevated structural elements which extend between a first, higher plane and a second, lower plane. A plurality of the structural elements has a substantially flat top surface extending in the first plane. This surface is bounded on all sides by facet-like, substantially flat, side surfaces which extend between the first and the second planes. The average surface roughness depth R.sub.a lies between 0.1 .mu.m and 10 .mu.m and the size of the structural elements ranges on average between 30 .mu.m and 180 .mu.m. The invention provides a quartz glass component particularly suitable for the adhesion of CVD layers and having a long service life.

Abstract: A silica glass member shows a glassy carbon coating wherein a surface of a silica glass substrate of the silica glass member shows a mean surface roughness (R.sub.a) in a range of 0.03 .mu.m to 2 .mu.m and it is coated with a glassy carbon coating. The member is manufactured by chemically roughening the substrate to a surface roughness in the above recited range; coating the surface of the silica glass substrate with an organic raw material containing carbon, curing and thereafter carbonizing the film of the organic raw material by forming a glassy carbon coating.

Abstract: Molded bodies of quartz glass have at least one surface area of transparent quartz glass, the exposed surfaces of which are smooth and which have a surface microroughness of less than 8 .mu.m. The base material has a chemical purity of at least 99.9% and a cristobalite content of no more than 1%; is gas-impermeable and opaque; and contains pores. At a wall thickness of 1 mm, the base material has a nearly uniform direct spectral transmission of less than 10% in the wavelength range of .lambda.=190-2,650 nm; and which has a density of at least 2.215 g/cm.sup.3. The transparent surface area is formed from base material by heating it to a temperature above 1,650.degree. C. The thickness of the transparent layer is at least 0.5 mm, and its direct spectral transmission in the wavelength range of .lambda.=6001-2,650 nm is at least 60% for a layer thickness of 1 mm.

Abstract: Quartz glass component having a coating with a silicon carbide surface includes a gradient layer of silicon carbide and at least one additional constituent which is less hard and has a lower modulus of elasticity than silicon carbide and whose concentration decreases across the thickness of the layer from inside to outside. The coated component has good thermal-shock resistance and long-term stability in terms of its chemical resistance to hydrofluoric acid and nitric acid as well as to a mixture of these two acids.