Performance comparison of x-ray absorption gratings fabricated by free deposition and centrifugal filling methods

Abstract

Free deposition and centrifugal filling methods are commonly used to fill metal particles into grating trenches for long-period X-ray absorption gratings. However, there has been no comparative analysis on the performance of absorption gratings fabricated by the two filling methods, and the difference between the two methods is not well understood. This paper compares the free deposition and centrifugal filling methods through the X-ray absorptivity of absorption gratings and the arrangement of tungsten nanoparticles (TNs) in grating trenches. It has been found that both particle filling methods densely arrange TNs in grating trenches differently but give almost equal X-ray absorptivity to the resulting gratings. The experimental results indicate that a centrifugal filling method is efficient for manufacturing X-ray absorption gratings with stable absorptivity. Furthermore, to verify the feasibility of the centrifugal filling process in fabricating short-period TNs-based absorption gratings, an absorption grating with a 10 μm period is manufactured by removing large-size TNs using centrifugal force. Hence, it has the potential to be used for the fabrication of absorption gratings with periods of several micrometers.