Abstract: A multilayer system and its production. Multilayer systems, such as those used as mirrors in the extreme ultraviolet wavelength range, suffer contamination or oxidation during storage in air and in long-time operation, i.e. when exposed to EUV radiation in a vacuum environment with certain partial pressures of water or oxygen, which causes a serious reduction in reflectivity. The multilayer system according to the invention will have a long life with constantly high reflectivity. Their reflectivity can be enhanced by barrier layers. The multilayer systems according to the invention have protective layers comprising iridium. The multilayer systems according to the invention are produced by direct, ion-beam-supported growth of the respective layer. The multilayer systems according to the invention are not only resistant to contamination and oxidation, but can also be cleaned if necessary, without losing reflectivity.

Abstract: It is in the object of the present invention to improve current deposition processes and devices for the fabrication of multilayer systems to better control the energy contribution at different stages of the deposition. This is achieved by depositing films by sputtering in a scheme providing for thermalized particles. One can get thermalized particles by choosing the working gas pressure and the distance between target and substrate to result in a mean free path of particles smaller than the distance between target and substrate or to result in a product of pressure and distance being larger than 2.0 cmPa.

Abstract: A process for the production of optical broad band elements for the ultra violet to hard x-ray wavelength range, especially the extreme ultra violet wavelength range is described. A set from series of layers made of at least two materials in relation to the layer sequence is designed and numerical optimization of the the layer thicknesses and of the cap layer thickness is performed. The materials are chosen in such a way that two successive layers interact with each other as little as possible or controllably. The set can be formed from MO2C— and Si-layers. The numerical optimization takes into account interlayers of a certain thickness and composition.

Abstract: In order to reduce contamination of optical elements which comprise a multilayer system on a substrate, it is proposed that the layer material and/or the layer thickness of at least one layer of the multilayer system are/is selected such that the standing wave which forms during reflection of the irradiated operating wavelength, forms a node of the electrical field intensity (node condition) in the area of the free interface of the multilayer system. Furthermore, a method for determining a design of a multilayer system, as well as a manufacturing process and a lithography apparatus are described.