title: High Dynamic Range Pixel Array Detector for Scanning Transmission Electron Microscopy.
abstract: We describe a hybrid pixel array detector (electron microscope pixel array detector, or EMPAD) adapted for use in electron microscope applications, especially as a universal detector for scanning transmission electron microscopy. The 128×128 pixel detector consists of a 500 µm thick silicon diode array bump-bonded pixel-by-pixel to an application-specific integrated circuit. The in-pixel circuitry provides a 1,000,000:1 dynamic range within a single frame, allowing the direct electron beam to be imaged while still maintaining single electron sensitivity. A 1.1 kHz framing rate enables rapid data collection and minimizes sample drift distortions while scanning. By capturing the entire unsaturated diffraction pattern in scanning mode, one can simultaneously capture bright field, dark field, and phase contrast information, as well as being able to analyze the full scattering distribution, allowing true center of mass imaging. The scattering is recorded on an absolute scale, so that information such as local sample thickness can be directly determined. This paper describes the detector architecture, data acquisition system, and preliminary results from experiments with 80-200 keV electron beams.
authors.affiliation: 1Laboratory of Atomic and Solid State Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Tate
authors.affiliation: 1Laboratory of Atomic and Solid State Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Prafull
authors.initials: P
authors.lastname: Purohit
authors.affiliation: 2Cornell High Energy Synchrotron Source (CHESS),Cornell University,Ithaca,NY 14853,USA.
authors.forename: Darol
authors.initials: D
authors.lastname: Chamberlain
authors.affiliation: 3School of Applied and Engineering Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Kayla X
authors.identifier: http://orcid.org/0000-0001-9253-7064
authors.initials: KX
authors.lastname: Nguyen
authors.affiliation: 3School of Applied and Engineering Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Hovden
authors.affiliation: 4Physics Department,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Celesta S
authors.initials: CS
authors.lastname: Chang
authors.affiliation: 4Physics Department,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Pratiti
authors.initials: P
authors.lastname: Deb
authors.affiliation: 3School of Applied and Engineering Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Emrah
authors.initials: E
authors.lastname: Turgut
authors.affiliation: 4Physics Department,Cornell University,Ithaca,NY 14853,USA.
authors.forename: John T
authors.initials: JT
authors.lastname: Heron
authors.affiliation: 5Department of Materials Science and Engineering,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Darrell G
authors.identifier: http://orcid.org/0000-0003-2493-6113
authors.initials: DG
authors.lastname: Schlom
authors.affiliation: 1Laboratory of Atomic and Solid State Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Ralph
authors.affiliation: 3School of Applied and Engineering Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Fuchs
authors.affiliation: 1Laboratory of Atomic and Solid State Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Katherine S
authors.initials: KS
authors.lastname: Shanks
authors.affiliation: 1Laboratory of Atomic and Solid State Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Hugh T
authors.initials: HT
authors.lastname: Philipp
authors.affiliation: 3School of Applied and Engineering Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Muller
authors.affiliation: 1Laboratory of Atomic and Solid State Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Sol M
authors.initials: SM
authors.lastname: Gruner
mesh_terms: D007091:Image Processing, Computer-Assisted / Q000379:methods*; D017348:Microscopy, Electron, Scanning Transmission / Q000295:instrumentation* / Q000379:methods*; D061848:Optical Imaging / Q000295:instrumentation* / Q000379:methods*
keywords: STEM; electron microscope pixel array detector (EMPAD); high dynamic range; mixed-mode pixel array detector (MM-PAD); pixel array detector (PAD)