Patent ID: 11923168
Assignee: FIBICS INCORPORATED
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G | IPC H

Claim 12:
13. The method of claim 12, wherein the sample has third and fourth linear fiducials each having ends electronically detectable on a rear cross-section surface of the sample defined by the x-y plane and each extending from the rear cross-section surface in a direction having the z-dimension component at known angles relative to the x-y surface, the method after step e. further including
positioning the rear cross-section surface of the sample for imaging by the imaging system and exposing another rear cross-section surface by the second charged particle beam,
setting a target distance r from the rear cross-section surface in the z-dimension, where r is a real number;
setting a rear slice distance of s, where s<r and s is a real number;
iteratively executing the steps of
f. scanning the rear cross-section surface with the first charged particle beam with the applied first drift compensation to obtain a rear slice image thereof by the imaging system;

g. exposing another rear cross-section surface defined by the x-y plane with a the second charged particle beam to the slice distance of s, and where an x dimension distance between ends of the third and fourth linear fiducials exposed in each rear cross-sectioned surface changes as a function of the z-dimension;
h. electronically calculating an actual rear slice distance in the z-dimension between a previous rear cross-section surface and the currently exposed rear cross-section surface based on a change in the x dimension distance and the angles;
h.1 updating the adjustment of parameters to advance the second charged particle beam in the z-dimension to the actual rear slice distance as the second drift compensation;
i. advancing the second charged particle beam in the z dimension with the second drift compensation for exposing a subsequent rear cross-section surface to at a distance in the z dimension from—the currently exposed rear cross-section surface that is closer to the rear slice distance s; and,
j. aggregating the actual rear slice distances and stopping the iterative execution of steps a-d when the aggregated actual rear slice distances is approximately the target distance r.