Characterization of the INTPIX4 SOI pixel detector in transmission electron microscopy at 120 keV and 200 keV.

Imaging performance with 120 and 200 keV electrons was evaluated with an integration-type silicon-on-insulator (SOI) pixel detector called INTPIX4 installed in a conventional transmission electron microscope. We demonstrated that single-electron events can be detected with INTPIX4 quantitatively. The gain and signals of single-electron events were measured. On the basis of the results, the yields of the collected charge for 120 and 200 keV electrons were estimated to be 96±5% and 97±5%, respectively. The modulation transfer function and detective quantum efficiency were also measured. INTPIX4 was clarified to have high detection efficiency and high sensitivity. We also found that it is necessary to use electron beams with energies less than 120 keV for INTPIX4 because multiple scattering of primary electrons at the silicon sensor degrades image resolution. This detector is expected to be applicable to low-dose observations in transmission electron microscopy.