Electrostatic Beam Blanker
Fast Electrostatic Beam Blanker (<100 psec. "Rise Time")
Fast stroboscopic imaging in voltage contrast, EBIC, OBIC, in experiments on decay-time measurement using cathodoluminescence-signals demands extremely high blanking frequencies. In electron-beam lithography the requirements regarding time-resolved switching are not quite so high. The beam blanker described on this page was optimized to achieve the shortest possible "rise time" values. It is the result of several years of development.
Researchers who are using this blanker measured the actual rise time: they found 35 to 50 picoseconds. Therefore, the term "100 picoseconds is a very comfortable figure for the manufacturer to guarantee.
Another point is the design of this beam blanker was the elimination of pulse distortions and reflexes. Pulse frequencies up to the Giga-Hz range are still clean and square (assuming good input pulses). 5-V-input pulses applied to the plates are sufficient to blank a 40 KeV beam.
The plates are very short (5.5 mm), therefore the flying-time effects are below the level of any detection method.
For a number of SEM columns, there are beam blanker adaptation kits ready. Often times however, the adapting is done for the first time on a given SEM. In such cases we must either take our own measurements, or work from the SEM maker's factory drawings of the column.
There are kits available for the following SEMs: ABT 55, Cambridge - almost all older models, CamScan S-4, Hitachi 2300 ... 2500, JEOL 840 ... 6400, Jeol T330, Leitz DSM 130, LEO 430, and 435, Philips 525, 535, TopCon 510, Zeiss 940, 960 and 962. Others upon request -this list is still growing.