Method for preparing a microscopic sample for FIB/SEM tomography

1 . A method of exposing a volume of interest (VOI) present in a bulk sample, the method comprising:

arranging the bulk sample in a first orientation relative to an optical axis of a particle beam system configured to provide a particle beam along its optical axis;

recording an image of the bulk sample while the bulk sample is in the first orientation;

based on the first image, defining a first trimming region which determines a location and a size of a first volume of the bulk sample;

using the particle beam to remove the first volume from the bulk sample to expose a first surface of the VOI;

arranging the bulk sample in a second orientation relative to the optical axis of the particle beam system, the second orientation being different from the first orientation;

recording a second image of the bulk sample while the bulk sample is in the second orientation;

based on the second image of the bulk sample, defining a second trimming region which determines a location and a size of a second volume of the bulk sample;

using the particle beam to remove the second volume from the bulk sample to expose a second surface of the VOI, the second surface being different from the first surface, the second surface directly contacting the first surface;

based on the second image, defining a third trimming region which defines a location and a size of a third volume of the bulk sample; and

using the particle beam to remove the third volume from the bulk sample to expose a third surface of the VOI, the third surface being different from both the first and second surfaces, the third surface directly contacting the first surface.

2 . The method of claim 1 , further comprising, after removing the first, second and third volumes of the bulk sample, tomographically analyzing the VOI.

3 . The method of claim 2 , wherein removing the first volume from the bulk sample exposes a cross-section plane that is parallel to the optical axis when the bulk sample is arranged in its first orientation.

4 . The method of claim 3 , wherein, when the bulk sample is in its second orientation, the cross-section plane faces the particle beam.

5 . The method of claim 4 , wherein the second volume is adjacent a first side of the VOI, the third volume is adjacent a second side of the VOI, and the first and second sides of the VOI are opposite sides of the VOI.

6 . The method of claim 5 , wherein the particle beam system comprises a rotation axis that allows arranging the bulk sample in the first orientation and in the second orientation by rotating the bulk sample around the rotation axis.

7 . The method of claim 1 , wherein removing the first volume from the bulk sample exposes a cross-section plane that is parallel to the optical axis when the bulk sample is arranged in its first orientation.

8 . The method of claim 1 , wherein:

removing the first volume from the bulk sample exposes a cross-section of the bulk sample; and

when the bulk sample is in its second orientation, the cross-section of the bulk sample faces the particle beam.

9 . The method of claim 1 , wherein the second volume is adjacent a first side of the VOI, the third volume is adjacent a second side of the VOI, and the first and second sides of the VOI are opposite sides of the VOI.

10 . The method of claim 1 , wherein the particle beam system comprises a rotation axis that allows arranging the bulk sample in the first orientation and in the second orientation by rotating the bulk sample around the rotation axis.

11 . The method of claim 10 , wherein the bulk sample is rotated by 90° around the rotation axis to move the bulk sample from the first orientation to the second orientation, and the bulk sample is rotated by −90° around the rotation axis to move from the second orientation to the first orientation.

12 . The method of claim 1 , wherein the particle beam system comprises a FIB system.

13 . The method of claim 1 , wherein the particle beam system comprises a laser system.

14 . One or more machine-readable hardware storage devices comprising instructions that are executable by one or more processing devices of a particle beam system to perform operations comprising:

arranging a bulk sample in a first orientation relative to an optical axis of the particle beam system configured to provide a particle beam along its optical axis, a volume of interest (VOI) being present in the bulk sample;

recording an image of the bulk sample while the bulk sample is in the first orientation;

based on the first image, defining a first trimming region which determines a location and a size of a first volume of the bulk sample;

using the particle beam to remove the first volume from the bulk sample to expose a first surface of the VOI;

arranging the bulk sample in a second orientation relative to the optical axis of the particle beam system, the second orientation being different from the first orientation;

recording a second image of the bulk sample while the bulk sample is in the second orientation;

based on the second image of the bulk sample, defining a second trimming region which determines a location and a size of a second volume of the bulk sample;

using the particle beam to remove the second volume from the bulk sample to expose a second surface of the VOI, the second surface being different from the first surface, the second surface directly contacting the first surface;

based on the second image, defining a third trimming region which defines a location and a size of a third volume of the bulk sample; and

using the particle beam to remove the third volume from the bulk sample to expose a third surface of the VOI, the third surface being different from both the first and second surfaces, the third surface directly contacting the first surface.

15 . A particle beam system comprising:

one or more processing devices; and

one or more machine-readable hardware storage devices comprising instructions that are executable by the one or more processing devices to perform operations comprising:

arranging a bulk sample in a first orientation relative to an optical axis of the particle beam system configured to provide a particle beam along its optical axis, a volume of interest (VOI) being present in the bulk sample;

recording an image of the bulk sample while the bulk sample is in the first orientation;

based on the first image, defining a first trimming region which determines a location and a size of a first volume of the bulk sample;

using the particle beam to remove the first volume from the bulk sample to expose a first surface of the VOI;

arranging the bulk sample in a second orientation relative to the optical axis of the particle beam system, the second orientation being different from the first orientation;

recording a second image of the bulk sample while the bulk sample is in the second orientation;

based on the second image of the bulk sample, defining a second trimming region which determines a location and a size of a second volume of the bulk sample;

using the particle beam to remove the second volume from the bulk sample to expose a second surface of the VOI, the second surface being different from the first surface, the second surface directly contacting the first surface;

based on the second image, defining a third trimming region which defines a location and a size of a third volume of the bulk sample; and

using the particle beam to remove the third volume from the bulk sample to expose a third surface of the VOI, the third surface being different from both the first and second surfaces, the third surface directly contacting the first surface.