EUV broadband mirrors

Motivation

Periodic multilayer mirrors for the EUV spectral range reflect only in a narrow spectral and angular range (typical for 13.5 nm: FWHM = 0.5 nm, FWHM = 10°). New coating designs allow enlarging the usable region. EUV broad band mirrors can be used for diverse applications such as coating of high-NA optics for EUV lithography, maximizing of integral reflectance using broad band EUV sources and optics for attosecond pulses.

 

Competencies

  • Calculation of vertical film thickness gradients (z gradings) using stochastic and deterministic design approaches
  • Realization of theoretic multilayer designs to fabricate broad band mirrors
  • Optimization of multilayer design with respect to wavelength, angular range, integral reflectance and phase behavior (chirped mirror)

 

Our work

  • Design, fabrication and characterization of broadband mirrors for the EUV spectral region according to customized requirements
  • Optimization of wavelength ranges, e.g. from 13 to 14 nm or from 12.5 to 15.5 nm
  • Optimization of angular ranges, e.g. from 0 to 20 degrees or from 0 to 30 degrees
  • Coating of different substrate materials (e.g. fused silica, silica, ULETM, Zerodur®)
  • Coating of different substrate geometries (e.g. flat, spheres, aspheres) up to diameter of 650 mm