Patent Number: 
Section: description

The structure of such a EUV projection exposure device is known per se in numerous variants, e.g. from the above-cited reference Jewell and Williamson and the references cited therein. It includes a EUV source 1, e.g., a synchrotron or a laser plasma focus source, which produces a EUV beam 2 with, e.g., 13 nm wavelength, or another wavelength in the preferred range of about 10-20 nm, for which suitable multilayer reflecting layers (see the reflecting layer 533, below) are available. An illuminating optics 3 serves for the suitable shaping of the EUV light as regards light conducting value, pupil filling, homogeneity, telecentricity, and the like. The mask 4 is thereby illuminated, shown as a transmission mask, but in many cases, however, preferably as a reflection mask. This mask 4 is imaged on a reduced scale by a projection objective 5 onto the object 6, the wafer. The projection objective 5 contains, as in many known designs, four curved mirrors 51, 52, 53, 54. The structure according to the invention is representatively shown on mirror 53 of these, with the silicon single crystal substrate 531, the thin cover layer 532 of amorphous quartz, which with xe2x80x9csuper-polishxe2x80x9d defines the highly accurate final contour of the mirror 53, and the multilayer reflecting layer 533. The latter gives, as a distributed Bragg reflector, a relatively high reflectivity of about 40-60% for a given spectral region. The shape of the substrate 531 is determined by the requirements of mechanical stability, cooling, installation into a mount, matching to the beam path (vignetting), and the like. The usable surface is first precisely optically polished to near the final contour. The thin amorphous quartz layer is then deposited. The CVD process, for example, is suitable for this. Deformations of the mirror surfaces due to strains in the layer 532 can be kept to a minimum by the process parameters and after-treatments. They can be kept to a minimum by deflection during the shaping of the substrate 531 and by corresponding polishing of the quartz layer 532. The amorphous quartz layer 532 thus does not serve as an adhesive base, diffusion barrier, or similar auxiliary layer of the multilayer reflection layers 533, but rather as the material which supports the contour of the mirror 53. The final shaping processing, the so-called xe2x80x9csuper-polishxe2x80x9d, thus follows after the coating with the quartz layer 532. A reflection layer 533, constructed as a multilayer EUV reflection layer, is then arranged on this layer 532 in a known manner. Mirrors constructed in this manner can of course be used at any other place of the projection exposure device and also in other devices, e.g., X-ray microscopes or telescopes. Each material of the substrate member, which is advantageous for the xe2x80x9cbulkxe2x80x9d, such as the above mentioned materials of low thermal expansion and at the same time high thermal conductivity, can be provided with a thin cover layer of material which can well be polished to optical quality. Conformity as regards adhesion properties, strains, corrosion, and the like can be attained with known criteria.