Multilayer reflective optics for EUV Lithography

Description

The peak reflectance of multilayer reflective optics is generally considered to be the key parameter of an EUVL optical system, but the bandwidth of the multilayers is equally important since it also determines the transmission of the system. In reality, there are much more factors that determine the optics performance. For instance the figure of the optics, with nm accuracy, and how this is affected by the approximately half micron of multilayer coating on top, and the coating induced stress. But also how the high frequency roughness of the substrates affects the multilayer performance. Another issue is the reflectance for out of band radiation, both deep UV and infrared light. What can be done to reduce this, and what is the effect on 13.5 nm reflectance? Furthermore lifetime issues, radiation induced damage, thermal stability, oxidation and cleaning resistance.
In this paper we will present the present status of the multilayer coated optics, including the latest achievements.

Period	12 Dec 2017
Event title	International MicroNanoConference, iMNC 2017
Event type	Conference
Location	Amsterdam, Netherlands
Degree of Recognition	International