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

Claim 11:
12. The method of claim 1, wherein the surface is a front cross-section surface and the operation is for removing material from the sample to provide a section of the sample, where the sample has x, y and z dimensions corresponding respectively to the first, second and third dimensions, with the at least two reference fiducials corresponding to first and second linear fiducials each having ends electronically detectable on the front cross-section surface of the sample defined by the x-y plane and each extending from the front cross-section surface in a direction having the z-dimension component at known angles relative to the x-y surface, the operation including;
setting a target distance m from the front cross-section surface in the z-dimension, where m is a real number;
setting a front slice distance of n, where n<m and n is a real number;
iteratively executing the steps of
a. scanning the front cross-section surface with the first charged particle beam with the applied first drift compensation to obtain a front slice image thereof by an imaging system;
b. exposing another front cross-section surface defined by the x-y plane with the second charged particle beam to the slice distance of n, and where an x dimension distance between ends of the first and second linear fiducials exposed in each front cross-sectioned surface as a function of the z-dimension;
c. electronically calculating an actual front slice distance in the z-dimension between a previous front cross-section surface and the currently exposed front cross-section surface based on a change in the x dimension distance and the angles;
c.1 updating the adjustment of parameters to advance the second charged particle beam in the z-dimension to the actual front slice distance as the second drift compensation;
d. advancing the second charged particle beam in the z dimension with the applied second drift compensation for exposing a subsequent front cross-section surface at a distance in the z dimension from the currently exposed front—cross-section surface that is closer to the front slice distance n; and,
e. aggregating the actual front slice distances and stopping the iterative execution of steps a-d when the aggregated actual front slice distances is approximately the target distance m.