A new ultra-precision profiler was developed to measure X-ray and EUV optics such as asymmetric and aspheric profiles. In the present study, the normal vectors at each point on the surface are determined by a reflected light beam that follows exactly the same path as the incident beam. The surface gradients at each point are calculated from the normal vector and the surface profile is obtained by integrating the gradient. The measuring instrument was designed according to the above principles. In the design, four goniometers and three-axis movers were applied to adjust the light axis to search for the normal vector at each point on the surface. The angle-positioning resolution and accuracy of each goniometer are respectively 1.8 x 10^-8 radian and 2 x 10^-7 radian. A SiC flat mirror 25.4 mm in diameter and an elliptical profile mirror for nanometer hard X-ray focusing were measured using the present instrument and compared to the measured profile using a Zygo Mark IVxp phase-measuring interferometer.

Date Published: 15 September 2005
PDF: 9 pages
Proc. SPIE 5921, Advances in Metrology for X-Ray and EUV Optics, 592107 (15 September 2005); doi: 10.1117/12.617986

Published in SPIE Proceedings Vol. 5921:
Advances in Metrology for X-Ray and EUV Optics
Lahsen Assoufid; Peter Z. Takacs; John S. Taylor, Editor(s)