[OPTICAL REVIEW Vol. 10, No. 5 (2003) 398-401]
© 2003 The Optical Society of Japan

Figure Error Correction by Reflection Wavefront Control of Cu Kα Grazing Incidence Multilayer Mirrors


Institute of Physics, Slovak Academy of Sciences, 845 11 Bratislava, Slovak Republic
1Research Center for Soft-X-ray Microscopy, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan

(Received February 28, 2003; Accepted May 30, 2003)

Reflection phase and amplitude of grazing incidence multilayer mirrors for CuKα radiation have been studied theoretically to evaluate phase correction effects of multilayer surface milling, which revealed good possibilities of correcting mirror substrate figure errors for focusing and imaging application. The mirror multilayers composed of base materials of Cu and Ni were studied in combination with Al, Be, C, Mg and Si for high reflectivity at a grazing angle of 3° incidence. The theoretical surface milling of Cu/Al multilayers of a period thickness of 1.478 nm provides phase correction of 1.7° per period, which corresponds to an accurate correction of substrate figure errors at a rate of 0.007 nm per period. Thus, the milling after the multilayer fabrication, compared to the milling before the multilayer fabrication, enables far more accurate phase correction with 200 times finer control.

Key words: X-ray mirror, multilayer, CuKα radiation, figure error, imaging