High-pressure plasma etching up to 9 atm toward uniform processing inside narrow grooves of high-precision X-ray crystal optics

Abstract

We developed a new etching technique using plasma generated at high pressure up to 9 atm. Operating at 9-atm pressure with a 30- μ m-diameter wire electrode, we demonstrated the generation of well-ordered plasma at a narrow gap of ∼10 μ m between the electrode and workpiece, and realized a high spatial resolution of <40 μ m during processing. This technique should allow for the processing of high-precision X-ray crystal optical devices with compact and complex structures, such as a micro channel-cut crystal monochromator with an extremely narrow (sub-100 μ m width) groove for realization of Fourier-transform-limited X-ray lasers with high intensity.

Keywords

• plasma etching
• X-ray crystal optics
• precision engineering