We have developed a new chemical etching process using tetramethyl ammonium hydroxide (TMAH) instead of the traditional potassium hydroxide (KOH) to fabricate silicon gratings taking advantage of Penn State's state-of-the-art Nanofabrication Facility supported by the NSF. The first set of etched gratings have surface quality comparable to the best silicon gratings developed by a team led by Jian Ge at Lawrence Livermore National laboratory (LLNL) using the KOH process in early 2000. For example, the scattered light level at 0.6238 μ m is less than 3%. The great advantage of this new approach is that it significantly simplifies the fabrication process of silicon gratings on large, thick silicon substrates. This new fabrication technique is being applied in the development of silicon grisms one inch in size for several near-IR astronomical instruments including the Gemini 8m telescope IR instruments, the Goddard Space Flight Center (GSFC) wide field near-IR multi-object spectrograph, and Steward Observatory PISCES near-IR camera and Arizona Imager and Echelle Spectrograph (ARIES). Status of the development and performance of the silicon grisms are reported. The development of silicon grisms is supported by the Penn State Eberly College of Sciences.
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2000