Coaxial opposing field spectrometer of high acceptance for secondary electrons and an electron beam test set

摘要

An electrostatic opposing field spectrometer having a device (SN) for evacuating secondary electrons, the device being rotationally symmetrical with respect to the direction of the primary electron beam (PE), is intended to take into account the spatial angle distribution of the velocity directions in the case of the secondary electrons (SE). According to the invention, an electrostatic opposing field spectrometer of the said type has an annular zone for guiding the secondary electrons (SE) outside the primary electron beam (PE). An opposing field spectrometer according to the invention images a measurement point of the sample (PR) in an astigmatic annular image on an annular detector. The invention is used for potential measurement at measurement points in a sample (PR). <IMAGE>