Presentation Information
[11a-PA2-3]Fabrication of a Si Slit for Space Ultraviolet Spectroscopy Using a Single-Sided Wet Etching Jig
〇(B)Itsuki Nagase1, Yuki Ashikari1, Tatsuya Sakamoto1, Biao Zhao2, Chiemi Oka1, Ryoichi Koga3, Yasuhiro Hirahara2, Seiichi Hata1 (1.Nagoya Univ. School of Eng., 2.Nagoya Univ. School of Sci., 3.Nagoya City Univ. School of Data Sci.)
Keywords:
ultraviolet spectroscopy,anisotropic etching,silicon micromachining
Ultraviolet (UV) spectroscopy is a key technique for next-generation space missions such as the LAPYUTA project, and the entrance slit governs the spectrometer performance. The slit for this mission requires a tapered backside opening that prevents vignetting of obliquely incident light and a low-roughness mirror surface. The tapered opening is formed by anisotropic wet etching of single-crystal silicon; however, only the backside must be etched while the front-side mirror is protected, which is difficult to be achieved by conventional immersion etching. In this study, we developed a dedicated single-sided wet etching jig with a TMAH circulation system that supplies the etchant only to the backside while protecting the mirror. Using the jig, a tapered opening with the intended 54.7-degree sidewall was etched to the target depth of about 200 um in about 10 h, demonstrating that single-sided wet etching is feasible while preserving the mirror surface.