EDET DH80k - characterization of a DePFET based sensor for TEM direct electron imaging

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 958; p. 162544
• Main Authors: Predikaka, Mitja, Bähr, Alexander, Koffmane, Christian, Ninković, Jelena, Prinker, Eduard, Richter, Rainer, Treis, Johannes, Wassatsch, Andreas
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2020
• Subjects: DePFET; Direct electron detection; Silicon sensors; Solid state detectors; Transmission electron microscopy; DePFET; Transmission electron microscopy; Silicon sensors; Direct electron detection; Solid state detectors
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2019.162544

In recent years, commercially available camera systems for transmission electron microscopy have greatly improved their spatial resolution, whereas temporal resolution was side tracked due to it being non-essential in the imaging of stationary objects. Consequently, a system needed for investigation of dynamic processes, e.g. protein folding, is not yet available. Therefore, the EDET DH80k camera system with a full frame readout frequency of 80kHz for a 1 Mpixel array is in development. Optimization steps were taken to improve spatial resolution by minimizing the impact of the multiple- and back-scattering of primary electrons. This is achieved by back-thinning of the sensor volume, removal of support layers and an optimized beam dump. With DePFET technology, a dynamic range of a minimum of 8 × 105 signal e− per pixel is achieved. An in-pixel signal compression is implemented by means of a nonlinear response function. Therefore, the sensitivity to single primary electrons as well as Poisson-limited sensitivity to numbers of 100 and more primary electrons is realized. In this paper, characterization measurements of the final pixel design are presented.