Cross-section processing-and-observation method and cross-section processing-and-observation apparatus

1. A cross-section processing-and-observation method comprising:

a cross-section exposure step of irradiating a sample with a focused ion beam to expose a cross-section of the sample;

a cross-sectional image acquisition step of irradiating the cross-section with an electron beam to acquire a cross-sectional image of the cross-section;

a step of repeatedly performing the cross-section exposure step and the cross-sectional image acquisition step along a predetermined direction of the sample at a setting interval to acquire a plurality of cross-sectional images of the sample; and

a specific observation target detection step of detecting a predetermined specific observation target from the cross-sectional image acquired at the cross-sectional image acquisition step;

wherein in the specific observation target detection step, after a predetermined specific observation target is detected, the setting interval of the cross-section exposure step is set to be shorter than that before the specific observation target is detected.

2. The cross-section processing-and-observation method according to claim 1 , wherein the setting interval is equal to or an integer multiple of a pixel size of the cross-sectional image, or the pixel size is an integer multiple of the setting interval.

3. The cross-section processing-and-observation method according to claim 1 , wherein

plural types of the specific observation targets are set, and

different condition setting of the cross-section exposure step and different condition setting of the cross-sectional image acquisition step are set for individual regions where the respective specific observation targets are detected.

4. The cross-section processing-and-observation method according to claim 3 , wherein when the condition setting of the cross-section exposure step and the condition setting of the cross-sectional image acquisition step are set, the setting interval is equal to or an integer multiple of a pixel size of the cross-sectional image.

5. The cross-section processing-and-observation method according to claim 1 , wherein in the specific observation target detection step, an EDS measurement or an EBSD measurement of the cross-section is performed.

6. The cross-section processing-and-observation method according to claim 1 , wherein the specific observation target detection step includes observing a contrast change of a cross-sectional image obtained in the cross-sectional image acquisition step.

7. The cross-section processing-and-observation method according to claim 3 , wherein the condition setting of the cross-section exposure step includes at least one of an accelerating voltage of the focused ion beam, a current value of the focused ion beam, an irradiation range of the focused ion beam in the sample, and a visual field range of the focused ion beam.

8. The cross-section processing-and-observation method according to claim 1 , wherein the specific observation target detection step is performed once while the cross-sectional image acquisition step is performed multiple times.

9. The cross-section processing-and-observation method according to claim 1 , wherein in the specific observation target detection step performed after the specific observation target is detected, cross-section processing-and-observation is not performed on other portions of the sample when the specific observation target is not detected anymore.

10. The cross-section processing-and-observation method according to claim 1 , further comprising a step of forming a correction mark by irradiation of the focused ion beam,

wherein in the cross-section exposure step, an image of the correction mark is acquired with a higher magnification than a visual field range of the focused ion beam among the conditions of the cross-section exposure step.

11. The cross-section processing-and-observation method according to claim 1 , further comprising a step of forming a correction mark by irradiation of the focused ion beam,

wherein in the cross-sectional image acquisition step, when the cross-sectional image is acquired, an image of the correction mark is acquired at the same time with a higher magnification than the magnification of a cross-section observation region observed by the electron beam.

12. A cross-section processing-and-observation apparatus comprising:

a sample stage on which a sample is to be placed;

a focused ion beam column configured to irradiate the sample with a focused ion beam;

an electron beam column configured to irradiate the sample with an electron beam;

one of a secondary electron detector and a backscattered electron detector configured to detect one of secondary electrons and backscattered electrons generated from the sample; and

a control unit configured to repeatedly perform a cross-section exposure step in which the sample is irradiated with a focused ion beam emitted from the focused ion beam column to expose a cross-section of the sample, and a cross-sectional image acquisition step in which the cross-section is irradiated with an electron beam emitted from the electron beam column to acquire a cross-sectional image of the cross-section along a predetermined direction of the sample at a setting interval;

wherein the control unit is further configured to periodically perform a specific observation target detection step of detecting a predetermined specific observation target from the cross-sectional image acquired at the cross-sectional image acquisition step; and

wherein in the specific observation target detection step, after a predetermined specific observation target is detected, the setting interval of the cross-section exposure step is set to be shorter than that before the specific observation target is detected.

13. The cross-section processing-and-observation apparatus according to claim 12 , wherein the control unit controls the setting interval to be equal to or an integer multiple of a pixel size of the cross-sectional image or controls the pixel size to be an integer multiple of the setting interval.