Hamamatsu Photonics has introduced a new silicon photodiode technology that is optimized to give high sensitivity for the direct detection of electrons. The S9904 is designed to detect electrons with energies from just 1 or 2 keV up to 20 keV.
The device has been specifically optimized for backscatter measurements inside scanning electron microscopes (SEMs), with the packaging and metal contacts designed to be non-magnetic, so the photodiode has no external influence on electron beam trajectories inside the instrument.
The S9904 photodiode has a large active area of 10 mm x 10 mm with a central hole 1 mm in diameter, to allow the main electron beam to pass through the sensor. For OEM customers Hamamatsu offer custom designed detector geometries, with larger or smaller size, together with multi-segment photodiode options, for example divided into four quadrants.
The excellent stability and reliability of the S9904 make it ideal for all electron detection applications, either used inside OEM instrumentation or for research applications.
