Fabrication of low blaze angle gratings by replication and plasma etch

Conference · 04 October 2022 · Advances in X-Ray/EUV Optics and Components XVII

DOI:https://doi.org/10.1117/12.2633512· OSTI ID:1963431

Park, Sooyeon; Voronov, Dmitriy L.; Wojdyla, Antoine; Gullikson, Eric M.; Salmassi, Fahard; Padmore, Howard A.

We suggest a new method of making ultra-low blaze angle gratings for synchrotron application. The method is based on reduction of the blaze angle of a master grating by replication followed by a plasma etch. A master blazed grating with a relatively large blaze angle is fabricated by anisotropic wet etching of a Si single crystal substrate. The surface of the master grating is replicated by a polymer material on top of a quartz substrate by nanoimprinting and then transferred into quartz by a plasma etch. Then a 2nd nanoimprint step is applied to transfer the saw-tooth surface into a resist layer on top of a Si grating substrate. The plasma etch through the patterned resist layer provides transfer of the grooves into the Si substrate and results in reduction of the blaze angle due to the difference in etch rates of the resist and Si. We investigated the impact of the replication process on the groove shape, facet surface roughness, and diffraction efficiency of the fabricated 200 lines/mm low blaze angle grating.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22), Scientific User Facilities Division (SC-22.3 )
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 1963431
• Journal Information: Advances in X-Ray/EUV Optics and Components XVII, Conference: Proceedings of SPIE - The International Society for Optical Engineering, San Diego, CA (United States), 21-26 Aug 2022
• Country of Publication: United States
• Language: English