We have recently developed a novel raster-scanning based X-ray microscopy method at the Hard X-ray Nanoprobe (HXN) beamline of National Synchrotron Light Source II [1]. Our new method can achieve sub-10 nm resolution with acquisition speed ~20 times faster than our previous approaches. The method utilizes ptychography in 2D fly-scan mode at an acquisition frame rate of 1250 diffraction patterns per second, currently limited by the fastest frame rate of the Eiger1 1M detector. By using ptychography, which is a coherent diffraction imaging method that reconstructs complex images of the sample through iterative phase retrieval algorithms [2], the sample image can be reconstructed at pixel size of 4.87 nm, providing imaging speed far beyond acquisition frame rate. As shown in Fig. 1(Left) is the reconstructed phase image of a Siemens star sample, our method can resolve the smallest features inside the pattern with 8 second of measurement time for a 2 µm x 2 µm field of view, effectively reaching an imaging speed of 23000 pixels per second.
Our new raster scan instrument also allows tomography measurement by acquiring 2D projections of the sample at different rotation angles. The sample stages and interferometry reference system are specially designed for precise rotation alignment with <0.5 µm drift to minimize tomography acquisition overhead and increase imaging speed. As shown in Fig. 1(Right) is the reconstructed phase tomogram of a cylindrical-shaped microelectronics sample extracted from an Intel® processor, the entire tomography acquisition took 53 minutes in real time for an imaged region of 2 µm diameter and 3 µm height. The zoom-in view in Fig. 1(Right) shows the smallest resolvable feature in the tomogram which appears to be metallic connectors in transistors. In this talk, I will cover the key concepts and technical implementations of our novel imaging method.