Calibration of a Scanning Electron Microscope: 1. Selection of the SEM Parameters

The influence of the parameters of a scanning electron microscope (SEM) on its calibration using test objects with a trapezoidal profile and large inclination angles of the side walls is studied. The focusing of the SEM probe and the energy of its electrons affect SEM calibration in the modes of collecting secondary slow electrons and backscattered electrons. It is shown that the microscope can be calibrated only in the low-voltage mode of operation with an energy of primary electrons less than 2 keV and in the mode of collecting secondary slow electrons with an energy of primary electrons more than 10 keV. A model of the formation of microscope signals in these energy ranges is presented. The influence of contamination on the lifetime of the test object and on the calibration accuracy of the scanning electron microscope is considered.