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.