Soft X-ray Reflection Ptychography

TL;DR

This paper introduces reflection geometry soft X-ray ptychography, enabling high-resolution, nondestructive imaging of bulk samples in the soft X-ray region, overcoming limitations of traditional transmission methods.

Contribution

It demonstrates the feasibility and spatial resolution of reflection geometry soft X-ray ptychography for the first time.

Findings

Achieved approximately 45 nm spatial resolution.

Validated the method using lithographically defined test patterns.

Showcased potential for nondestructive, bulk material imaging.

Abstract

Scanning transmission X-ray microscopy and ptychography have become mature tools for high-resolution, element-specific imaging of nanoscale structures. However, transmission geometries impose stringent constraints on sample thickness and preparation, thereby limiting investigations of extended or bulk specimens, especially in the soft X-ray region. Here, we demonstrate reflection geometry soft X-ray ptychography as a robust imaging mode. Instrumental feasibility and spatial resolution are established using a lithographically defined Siemens star and barcode test pattern on a multilayer substrate. We empirically demonstrate a full-pitch spatial resolution of ca. 45 nm from Fourier ring correlation analysis of the reconstructed object. The results highlight the potential of the reflection geometry for nondestructive X-ray studies of materials without the need for transmissive samples.