| 摘要 |
With a detector system for the specimen chamber of a scanning electron microscope, signals are simultaneously detected in transmission which signals correspond to a light field contrast and a dark field contrast. The detector system ( 14 ) includes four detectors ( 15 to 18 ) in a plane ( 25 ) between which an aperture ( 19 ) for free access of electrons is located. Behind the aperture ( 19 ), a further detector ( 27 ) is arranged in a second plane ( 26 ). The detectors are preferably diodes. The detectors ( 15, 16, 17, 18 ) in the first plane ( 25 ), which is closer to the specimen, serve to generate signals which correspond to a dark field contrast. The further detector ( 27 ), more distant from the specimen, detects signals corresponding to a light field contrast. Large dead spaces, which are not sensitive to electrons, between the diodes and around the aperture ( 19 ), can be avoided by the offset arrangement of four diodes ( 15, 16, 17, 18 ) in the first plane ( 25 ).
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