Magnetic Field Assisted Finishing of Silicon MEMS Micro-Pore X-Ray Optics

An alternating magnetic field assisted finishing (MAF) technique has been developed to finish the 5–20 μm wide pore sidewalls of micro-pore X-ray focusing optics fabricated using micro-electro-mechanical systems (MEMS) techniques. To understand the material removal mechanism, this MAF technique is used to finish a silicon MEMS micro-pore X-ray optic that had previously undergone a hydrogen annealing treatment. Compared to the unfinished surface, distinctive surface features are observed on the finished surfaces using scanning electron microscopy, optical profilometry, and atomic force microscopy. This demonstrates the finishing characteristics and reveals the material removal mechanism on the nanometer scale. Moreover, the representative unfinished and finished micro-pore sidewall surfaces show a reduction in roughness due to finishing from 1.72 to 0.18 nm Rq.