High-Speed Direct-Detection Electron Detector for the TEAM Project High-Speed Direct-Detection Electron Detector for the TEAM Project P. Denes,* M. Battaglia,** D. Contarato,* D. Doering,* P. Giubilato***, D. Gnani*, B. Krieger* and V. Radmilovic* * Lawrence Berkeley National Laboratory, Berkeley, CA 94720, ** Department of Physics, University of California Santa Cruz, CA 95064 *** Dipartimento di Fisica, Universita` degli Studi, Padova, I-35131, Italy Monolithic CMOS Active Pixel Sensors (APS), first described in 1967 [1],[2] are widely used today in both low- and high-end digital photography. The same technology can, with suitable modification, be used as a direct detector of electrons [3],[4]. For the TEAM (Transmission Electron Aberration-corrected Microscope) project [5]. a 400 frame-per-second APS-based detector has been developed. This detector was engineered through a sequence of design optimizations including precise modeling of electron interactions in the detector together with radiation hardening [6],[7] together with improvements in imaging modes [8]. The detector has a pixel pitch of 9.5 µm, with a Point Spread Function (PSF) of roughly 8 µm at 300 keV. In a “cluster counting” mode, the PSF can be reduced to 2 µm, as shown in FIG. 1. The operation of the TEAM detector, together with initial experimental results, will be described. Current developments, in technology further advanced than that used for TEAM will also be described. References [1] G. Wecklers, .”Operation of p-n junction photodetectors in a photon flux integrating mode”., IEEE J. Solid-State Circuits, Vol. SC-2, p. 65, 1967. [2] P. Noble, .”Self-scanned image detector arrays”., IEEE Trans. Electron Devices, Vol. ED-15, p. 202, 1968. [3] NH Xuong, et al. “First use of a high-sensitivity active pixel sensor array as a detector for electron microscopy”, Proc. SPIE, Vol. 5301 (2004) 242. [4] A.R. Faruqi, D. M. Cattermole and C. Raeburn, Nucl.Instrum.Meth., Vol. 513 (2003) 317. [5] C. Kisielowski, et al. “Detection of Single Atoms and Buried Defects in Three Dimensions by Aberration-corrected Electron Microscopy with 0.5 Å Information Limit”,, Microscopy and Microanalysis 14454-462. [6] M. Battaglia et al., “A Rad-hard CMOS Active Pixel Sensor for Electron Microscopy”, Nucl.Instrum.Meth., Vol. 598 (2009) 642. [7] M. Battaglia et al., CMOS Pixel Sensor Response to Low Energy Electrons in Transmission Electron Microscopy”, Nucl.Instrum.Meth., Vol.605 (2009) 350. [8] M. Battaglia et al., “Cluster Imaging with a Direct Detection CMOS Pixel Sensor in Transmission Electron Microscopy”, Nucl.Instrum.Meth., Vol.608 (2009) 363. 156 doi:10.1017/S1431927610062215 Microsc. Microanal. 16 (Suppl 2), 2010 © Microscopy Society of America 2010 https://doi.org/10.1017/S1431927610062215 Downloaded from https://www.cambridge.org/core. Carnegie Mellon University, on 06 Apr 2021 at 01:16:21, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S1431927610062215 https://www.cambridge.org/core https://www.cambridge.org/core/terms FIG. 1. Point Spread Function in the TEAM detector as a function of electron energy. Points represent measured values in “integrating” and “counting” imaging modes, and curves represent predictions from simulation. Microsc. Microanal. 16 (Suppl 2), 2010 157 https://doi.org/10.1017/S1431927610062215 Downloaded from https://www.cambridge.org/core. Carnegie Mellon University, on 06 Apr 2021 at 01:16:21, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S1431927610062215 https://www.cambridge.org/core https://www.cambridge.org/core/terms