Very-High Dynamic Range, 10,000 frames/second Pixel Array Detector for Electron Microscopy

Abstract

Precision and accuracy of quantitative scanning transmission electron microscopy (STEM) methods such as ptychography, and the mapping of electric, magnetic and strain fields depend on the dose. Reasonable acquisition time requires high beam current and the ability to quantitatively detect both large and minute changes in signal. A new hybrid pixel array detector (PAD), the second-generation Electron Microscope Pixel Array Detector (EMPAD-G2), addresses this challenge by advancing the technology of a previous generation PAD, the EMPAD. The EMPAD-G2 images continuously at a frame-rates up to 10 kHz with a dynamic range that spans from low-noise detection of single electrons to electron beam currents exceeding 180 pA per pixel, even at electron energies of 300 keV. The EMPAD-G2 enables rapid collection of high-quality STEM data that simultaneously contain full diffraction information from unsaturated bright field disks to usable Kikuchi bands and higher-order Laue zones. Test results from 80 to 300 keV are presented, as are first experimental results demonstrating ptychographic reconstructions, strain and polarization maps. We introduce a new information metric, the Maximum Usable Imaging Speed (MUIS), to identify when a detector becomes electron-starved, saturated or its pixel count is mismatched with the beam current.

References in corpus (4)

• Electron ptychography achieves atomic-resolution limits set by lattice vibrations
• Comparison of optimal performance at 300 keV of three direct electron detectors for use in low dose electron microscopy
• High pressure floating zone growth and structural properties of ferrimagnetic quantum paraelectric BaFe${}_{12}$O${}_{19}$
• Emergent chirality in a polar meron to skyrmion phase transition

Cited by in corpus (9)

• A roadmap for edge computing enabled automated multidimensional transmission electron microscopy
• Ultrafast Radiographic Imaging and Tracking: An overview of instruments, methods, data, and applications
• PtyRAD: A High-performance and Flexible Ptychographic Reconstruction Framework with Automatic Differentiation
• 3D Atomic-Scale Metrology of Strain Relaxation and Roughness in Gate-All-Around (GAA) Transistors via Electron Ptychography
• Removing constraints of 4D-STEM with a framework for event-driven acquisition and processing
• Ultra-fast Digital DPC Yielding High Spatio-Temporal Resolution for Low-Dose Phase Characterisation
• Low barrier ZrO${}_x$-based Josephson junctions
• Defect contrast with 4D-STEM: Understanding crystalline order with virtual detectors and beam modification
• Nanoscale Polar Landscapes in Quantum Paraelectric SrTiO3