METHOD OF PROCESSING SIGNALS IN SCANNING DEVICES Russian patent published in 2014 - IPC G02B27/64 

FIELD: physics.

SUBSTANCE: method involves using an electron beam to scan the surface of an object across a topographical feature situated on that surface, while simultaneously changing the value of the controlled parameter for each scanning line; obtaining a secondary-emission signal; converting that signal to digital; storing and analysing values of that signal to determine the best focusing conditions; the method being characterised by that for each record, the signal contrast value is determined, the relationship between that contrast and the controlled parameter is analysed; that relationship is used to determine unique correspondence between the controlled parameter and the position of the focal point relative to the object and that point is placed at the required position.

EFFECT: shorter time required to perform auxiliary procedures for setting given beam parameters.

5 cl, 5 dwg