| 摘要 |
The present invention deals with a secondary electron detector ( 1 ), especially in a scanning electron microscope. The subject matter of the invention provides a secondary electrons detector ( 1 ) constituted by a sensor ( 2 ) located in a detector chamber ( 3 ), to which a vacuum air pump ( 10 ) is connected to produce vacuum inside the detector chamber ( 3 ), the detector chamber ( 3 ) being in its wall near to the active surface of the sensor ( 2 ) enclosed with a diaphragm featuring high resistance to the transmission of gas and low resistance to the transmission of the electrons. The electrically conductive grid ( 11 ) is produced either in the form of a copper screen or as a kapton membrane ( 12 ) with orifices ( 13 ) and it is equipped on both sides with conductive coating ( 14, 15 ). Outside the detector chamber ( 3 ), the electrically conductive grid ( 11 ) is covered with an input screen ( 18 ), which is usually of hemispherical shape and is connected to the low voltage source ( 19 ) of 80 to 150 V.
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