In x-ray applications, x-ray zone plates are very useful as microfocusing components in x-ray optics. This paper presents both theoretical consideration and the fabrication procedure for producing π-phase shift x-ray zone plates for x-ray focusing in the range of 800 eV to 1700 eV in x-ray scanning photon emission microscopy by x-ray mask technology. The x-ray zone plates are fabricated on 0.7 μm low-stress silicon-rich silicon nitride (SiN x ) membranes with tri-layer Chromium-Tungsten-Chromium (Cr-W-Cr) as x-ray absorbers instead of Nickel or Gold. The SiN x film is deposited on the (100) silicon substrate using low pressure chemical vapor deposition (LPCVD), and the free standing membranes are formed by means of KOH silicon backside etching. With e-beam lithography and reactive ion etching, a width of 0.8 μm of outmost zone of the x-ray zone plates was obtained. Scanning electron microscopy (SEM) images of the x-ray zone plates are shown.
|Number of pages
|Proceedings of the National Science Council, Republic of China, Part A: Physical Science and Engineering
|Published - 1 Nov 1997