摘要 |
A method and a device for determining the distance from the sample to be examined to at least one reference point which function independently of the type of sample. A signal is modulated to a first potential of a sample and a primary particle beam is directed at the sample, resulting in a secondary particle beam being formed by an interaction, the particles of this beam having the modulated signal. The particles of the secondary particle beam and the signal modulated to the potential of the particles of the secondary particle beam are detected. By comparing the detected modulated signal to a reference signal, the distance is determined from the relationship between the reference signal and the detected modulated signal. The device has the corresponding components for implementing the method.
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