| 摘要 |
The combined directional electron detector, intended particularly for environmental scanning electron microscopes with variable gas pressure in the sample chamber, also dedicated to the multidetector three-dimensional imaging of surface topographies, has an intermediate chamber (16) situated on the path of the electron beam (EB) to the sample stage (2), filled with gas with an intermediate pressure (P 2 ) lower than the working gas pressure (P 1 ) in the sample chamber where the place of emission of the electrons subject to detection is located, is equipped with a lower aperture (1) throttling the flow of the gas to the intermediate chamber (16) and in the space between the intermediate chamber (16) and the sample stage (2) it has four anodes (3) in the form of four electrodes identical in shape, arranged in pairs symmetrically around the electron beam (EB) axis, equipped with separate electrical leads and positively biased relative to the wall of the intermediate chamber (16). In the space between the anodes (3) and the sample stage (2) there is an external screening cathode (6) with a hole, delimiting from the sample stage (2) side the maximal backscattered electron (BSE 2 ) detection angle (² 2 ) at which the electrons enter the electric discharge area around the anodes (3). Inside the intermediate chamber (16) there is a quadrant semiconductor BSE 1 detector (13) with four identical sectors active for electrons, arranged symmetrically relative to the electron beam (EB) axis, with their active surfaces facing the lower throttling aperture (1). |
