Method for incorporating temperature-regulating hollow structures into a substrate, in particular into a substrate for an optical element for an euv projection exposure apparatus, and processing system therefor, method and substrate for producing an optical element, optical element, and semiconductor technology apparatus

A method for incorporating temperature-regulating hollow structures into a substrate for a mirror for an EUV projection exposure apparatus, comprising:

• providing a substrate consisting of a substrate material;
• progressively focusing a processing light beam onto processing locations at which temperature-regulating hollow structures are intended to arise, so that the substrate material is ablated at the processing locations, wherein adjacent to the processing locations modified substrate material arises, the modified substrate material having an increased susceptibility to a chemically active treatment medium relative to the substrate material;
• applying the treatment medium to the processing locations while progressively focusing the light beam onto the processing locations, wherein the treatment medium exhibits an effect at the processing locations and removes modified the substrate material present there;
• and
• applying a rinsing fluid to the processing locations while progressively focusing the light beam onto the processing locations such that ablated substrate material is rinsed away.