The Velociprobe: An ultrafast hard X-ray nanoprobe for high-resolution ptychographic imaging

• Published in: Review of scientific instruments 2019-08, Vol.90 (8), p.083701-083701
• Main Authors: Deng, Junjing, Preissner, Curt, Klug, Jeffrey A., Mashrafi, Sheikh, Roehrig, Christian, Jiang, Yi, Yao, Yudong, Wojcik, Michael, Wyman, Max D., Vine, David, Yue, Ke, Chen, Si, Mooney, Tim, Wang, Maoyu, Feng, Zhenxing, Jin, Dafei, Cai, Zhonghou, Lai, Barry, Vogt, Stefan
• Format: Article
• Language: English
• Subjects: Algorithms; Control algorithms; Control theory; High resolution; Image resolution; Integrated circuits; Multilayers; Scanning; Scientific apparatus & instruments; Spatial data; Spatial resolution; X ray sources; Zone plates
• ISSN: 0034-6748; 1089-7623
• DOI: 10.1063/1.5103173

Motivated by the advanced photon source upgrade, a new hard X-ray microscope called “Velociprobe” has been recently designed and built for fast ptychographic imaging with high spatial resolution. We are addressing the challenges of high-resolution and fast scanning with novel hardware designs, advanced motion controls, and new data acquisition strategies, including the use of high-bandwidth interferometric measurements. The use of granite, air-bearing-supported stages provides the necessary long travel ranges for coarse motion to accommodate real samples and variable energy operation while remaining highly stable during fine scanning. Scanning the low-mass zone plate enables high-speed and high-precision motion of the probe over the sample. With an advanced control algorithm implemented in a closed-loop feedback system, the setup achieves a position resolution (3σ) of 2 nm. The instrument performance is evaluated by 2D fly-scan ptychography with our developed data acquisition strategies. A spatial resolution of 8.8 nm has been demonstrated on a Au test sample with a detector continuous frame rate of 200 Hz. Using a higher flux X-ray source provided by double-multilayer monochromator, we achieve 10 nm resolution for an integrated circuit sample in an ultrafast scan with a detector’s full continuous frame rate of 3000 Hz (0.33 ms per exposure), resulting in an outstanding imaging rate of 9 × 104 resolution elements per second.