Patent ID: 6992287

Claim:
A method of identifying an optimal landing energy of a probe current in a scanning electronic microscope for use in obtaining an optimal topographic image of a sample, comprising the steps of: (a) directing the probe current to the sample at a selected landing energy to produce a signal electron beam from the sample; (b) measuring the probe current; (c) providing a signal electron beam current detector; (d) receiving the signal electron beam at the signal electron beam current detector to obtain a signal electron beam current measurement; (e) calculating a ratio of the signal electron beam current measurement to the measured beam energy of the probe current; (f) repeating steps (a) through (e) at a landing energy other than the selected landing energy; and (g) comparing the calculated ratios at each landing energy to identify the optimal landing energy as a landing energy corresponding to a ratio having a value proximate “1”; (h) selecting the identified optimal landing energy; and (i) obtaining substantially the entire topographic image of the sample by directing the probe current to the sample at a single landing energy which is the optimal landing energy, and directing a resulting signal electron beam to an imaging detector.