title: FEI's direct electron detector developments: Embarking on a revolution in cryo-TEM.
abstract: In early 2011 FEI Company launched the "Falcon", its first commercial direct electron detector product intended for application in 3-D electron microscopy in the life sciences. In this paper we discuss the principle of direct electron detection and its implementation in Falcon cameras. We describe the signal formation in the sensor and its impact on the detection quantum efficiency (DQE) of the sensor. Insights into the signal formation led us to improved camera designs. Three significant improvements are discussed. (1) Back thinning of the sensor. This is implemented in the second-generation Falcon (Falcon 2), where the sensor thickness is reduced to 50 μm, and in the latest generation Falcon 3 detector with further back-thinning down to 30 μm. (2) The introduction of electron counting, a signal processing technology implemented in Falcon 3. (3) Dose fractionation mode, which allows the user to access intermediate results during the illumination of the sample.
authors.affiliation: FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands.
authors.forename: Maarten
authors.initials: M
authors.lastname: Kuijper
authors.affiliation: FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands.
authors.forename: Gerald
authors.initials: G
authors.lastname: van Hoften
authors.affiliation: FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands.
authors.forename: Bart
authors.initials: B
authors.lastname: Janssen
authors.affiliation: FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Geurink
authors.affiliation: FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands. Electronic address: Sacha.DeCarlo@fei.com.
authors.forename: Sacha
authors.initials: S
authors.lastname: De Carlo
authors.affiliation: FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands.
authors.forename: Matthijn
authors.initials: M
authors.lastname: Vos
authors.affiliation: FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands.
authors.forename: Gijs
authors.initials: G
authors.lastname: van Duinen
authors.affiliation: FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands.
authors.forename: Bart
authors.initials: B
authors.lastname: van Haeringen
authors.affiliation: FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands.
authors.forename: Marc
authors.initials: M
authors.lastname: Storms
mesh_terms: D020285:Cryoelectron Microscopy / Q000379:methods*; D004583:Electrons; D021621:Imaging, Three-Dimensional / Q000379:methods*
keywords: CMOS; Cryo-EM; DQE; Direct electron detector; Electron counting; MTF; TEM