Nanoscale Surface Modifications by Magnetic Field Assisted Finishing

Abstract

A magnetic fieldassisted finishing (MAF) process has been developed to reduce the sidewall surface roughness of the 5–20 خ¼m wide curvilinear pores of microelectromechanical systems micropore Xray optics to <1 nm Rq. Although the feasibility of this process has been demonstrated on these optics, a clear understanding of the MAF process' material removal mechanisms has not been attained. In an attempt to discover these mechanisms, the MAF process is applied to a flat workpiece, allowing for direct observation and tracking of changes to distinctive surface features before and after MAF. Atomic force microscopy, fieldemission scanning electron microscopy, and energydispersive Xray spectroscopy are used to analyze the surface morphology and composition with respect to finishing time. These observations suggest that the MAF process modified the surface, reducing surface roughness (from 0.8 nm to 0.6 nm Rz on silicon) by removing relatively lowwavelength surface features. Moreover, the MAF process appears to modify the surface mechanically.