Robust, High Speed, Direct-Electron Microscopy Detector Array

New detectors with improved resolution, speed, and sensitivity will increase the efficacy of electron beam microcharacterization, thereby stimulating innovations in life and materials sciences. Current instruments based on charge couple devices (CCDs) are readout-speed limited and are phosphor-limited in resolution and efficiency. Therefore, a new electron detector technology ¿ which offers high efficiency, high spatial resolution, and high temporal resolution ¿ is needed for both low- and high-energy electron imaging. To eliminate phosphor inefficiencies, this project will develop a monolithic, radiation hard, SOI CMOS (silicon-on-insulator, complimentary metal oxide semiconductor) direct-electron imager with resolution less than 20 micron pixel, a dynamic range greater than 18-bits, and kHz frame rates. Unlike CCDs, pixel detectors do not have the equivalent of dark current or readout noise, despite operating at room temperatures; the absence of readout noise allows improved statistics by `noise-less¿ summation of images. Phase I will design and manufacture prototype arrays of SOI CMOS active pixel sensor electron detectors. Sensitivity, dynamic range, and temporal response for direct electron imaging will be determined, and reliability will be established. In Phase II, fully functional, high frame rate, 1280x1280 element, 15-micron pixel electron detector arrays will be developed. Commercial Applications and Other Benefits as described by the awardee: More efficient electron microscopy detectors would play a major role in the solution and understanding of the structure of biological molecules and macro-molecular complexes. Higher quality electron microscopes would permit the use of electron tomography on single particles (e.g., viruses) at near atomic resolution.