Towards Sub-micrometer High Aspect Ratio X-ray Gratings by Atomic Layer Deposition of Iridium

TL;DR

This paper presents a novel fabrication method for high aspect ratio iridium X-ray gratings using deep reactive ion etching and atomic layer deposition, enhancing the sensitivity of phase contrast imaging.

Contribution

It introduces a new process combining silicon etching and iridium ALD to produce sub-micrometer high aspect ratio X-ray gratings.

Findings

Successfully fabricated 1 μm period, 30 μm deep iridium gratings.

Demonstrated potential for improved X-ray phase contrast imaging.

Enhanced grating absorption and sensitivity.

Abstract

X-ray grating interferometry is an excellent technique for X-ray phase contrast imaging and X-ray wavefront sensing with applications in materials science, biology and medical diagnosis. Among other requirements, the method depends on the availability of highly X-ray absorbing metallic gratings. Here, we report on the fabrication and characterization of high aspect ratio iridium gratings with a period of one micrometer and a depth of 30 micrometer combining deep reactive ion etching of silicon and atomic layer deposition of iridium. The implementation of such structures can greatly enhance the sensitivity of grating-based X-ray phase contrast imaging and thus, expand further its broad range of applications.