A research group led by Assistant Professor Toshihide Tsuru and Assistant Professor Tadashi Hatano at Institute of Multidisciplinary Research for Advanced Materials, Tohoku University has successfully performed demonstration on a technology to control reflection wavefronts of soft X-ray multilayer mirrors with an accuracy of 0.1 nm.

A wavelength of soft X-rays is as short as a tenth to a hundredth of that of visible light. A multilayer mirror with alternating layers of two materials can reflect soft X-ray, while a conventional mirror can not.
High-resolution imaging is available by a combination of soft X-rays and a multilayer mirror that have been developed as key components of a microscope or a telescope.

Reflection phase of soft X-ray multilayer mirror with some surface layers partially removed by ion milling has been successfully measured using Young's interferometer.
It has been confirmed that wavefronts can be controlled with an accuracy of 0.1 nm by period-by-period removal of surface layers.

The surface finishing technology of soft X-ray mirror plays an important role for realizing an ultimate-resolution imaging system with the resolution of 10 nm.
After a substrate of a 1 nm accuracy that the recent technology has reached is coated with a multilayer, the surface layers are removed to reduce wavefront errors to the 0.1 nm level. The correction method of high-precision multilayer mirror is expected to be applied to various devices including lithography, microscopes and telescopes.

The achievement has been published in "Hoshako (Synchrotron radiation)" by the
Japanese Society for Synchrotron Radiation Research, and appeared on the front cover of the May issue.  The research was supported by Development of Systems and Technology for Advanced Measurement and Analysis, Japan Science and Technology Agency (JST).

More Information (Japanese)

[Contact]
Assistant Professor Toshihide Tsuru
Assistant Professor Tadashi Hatano
Institute of Multidisciplinary Research for Advanced Materials, Tohoku
University
TEL: +81-22-217-5330
E-mail: tsuru*tagen.tohoku.ac.jp (Replace * with @)
E-mail: hatano*tagen.tohoku.ac.jp (Replace * with @)