To improve the resolution and the sensitivity of optical metrology, we have constructed an interferometer for vacuum-ultraviolet wavelengths. To examine the influence of the wavelength, especially with regard to the period of the object’s structure, we chose an apochromatic design. With reflective optics, wavelengths from 157 to 900 nm can be employed for interferometric measurements. The benefits and also the technological problems that accompany the use of vacuum-ultraviolet wavelengths are discussed. The design of this interferometer and measuring results with different wavelengths are presented.
© 1999 Optical Society of America
Wolfgang Emer and Johannes Schwider, "Ultraviolet Interferometry with Apochromatic Reflection Optics," Appl. Opt. 38, 3516-3522 (1999)