Automated application of drift correction to sample studied under electron microscope

Patent metadata

Field	Value
Publication number	US-11477388-B2
Application number	US-202117545651-A
Country	US
Kind code	B2
Filing date	Dec 8, 2021
Priority date	Aug 16, 2019
Publication date	Oct 18, 2022
Grant date	Oct 18, 2022

Abstract

Control system configured for sample tracking in an electron microscope environment registers a movement associated with a region of interest located within an active area of a sample under observation with an electron microscope. The registered movement includes at least one directional constituent. The region of interest is positioned within a field of view of the electron microscope. The control system directs an adjustment of the electron microscope control component to one or more of dynamically center and dynamically focus the view through the electron microscope of the region of interest. The adjustment comprises one or more of a magnitude element and a direction element.

First claim

What is claimed is:

1. A control system configured for sample tracking in an electron microscope environment, the control system comprising:
a memory; and
a processor;
wherein the control system is configured to:
register a movement associated with a region of interest located within an active area of a sample under observation with an electron microscope,
wherein the registered movement includes at least one directional constituent, and
wherein the region of interest is positioned within a field of view of the electron microscope; and

calculate an electron dose for the region of interest as a function of a position of the sample under observation, a beam configuration of the electron microscope, and time.

2. The control system of claim 1 , wherein the control system is further configured to allow a user to set an electron dose limit for the sample under observation.

3. The control system of claim 2 , wherein the control system is further configured to monitor that the electron dose does not exceed the electron dose limit.

4. The control system of claim 1 , wherein the control system is further configured to:
display, on a graphical user interface, an image of the electron dose in a heatmap form; and,
automatically adjust the displayed image to in response to a change in one or more of a sample position and a magnification level, wherein the adjustment is based on the change.

5. The control system of claim 4 , wherein a pre-determined electron dose limit is used as a metric in the heatmap form.

6. The control system of claim 1 , wherein the control system is further configured to perform a calibration process to improve an effectiveness of the determination of the electron dose, wherein the calibration process determines one or more calibration values associated with the calibration.

7. The control system of claim 6 , wherein the control system is further configured to perform at least one of the following: store the one or more calibration values associated with the calibration in a calibration database; compare a measured value from the electron microscope against the one or more calibrated values on a periodic basis; and monitor performance of the control system against the one or more calibration values.

8. The control system of claim 6 , wherein the control system is further configured to store data representing beam current per microscope configuration of the electron microscope as a profile and retrieve measured values from the stored data or determine interpolated values from the stored data as a user changes beam conditions on the microscope during use.

9. The control system of claim 6 , wherein the control system is further configured to store data representing beam area per microscope configuration as a profile and retrieve measured values from the stored data or determine interpolated values from the stored data as a user changes beam conditions on the microscope during use.

10. The control system of claim 1 , wherein the electron dose is represented as an electron dose rate.

11. The control system of claim 10 , wherein the control system is further configured to allow a user to set an electron dose rate limit for the sample under observation.

12. The control system of claim 11 , wherein the control system is further configured to monitor that the electron dose rate does not exceed the electron dose rate limit.

13. The control system of claim 1 , wherein the electron dose is represented as a cumulative electron dose.

14. The control system of claim 1 , wherein the control system is further configured to allow a user to set one or more safety limits to prevent damage to the sample.

15. The control system of claim 1 , wherein the control system is further configured to measure an impact of an electron beam on one or more of: a shape of the sample under observation, a composition of the sample under observation, a density of the sample under observation, an electrical characteristic of the sample under observation, a morphology of the sample under observation, and a microstructure of the sample under observation.

16. The control system of claim 15 , wherein the control system is further configured use image analysis to quantify degradation of crystalline structure to determine sample limits of the electron dose.

17. The control system of claim 16 , wherein the control system is further configured to:
display a Fast Fourier Transform (“FFT”) on a graphical user interface, wherein the FFT is displayed in association with an image from the region of interest;
receive a user selection of an area of the FFT; and
track an intensity in the selected area over time under specified electron beam conditions to identify a critical threshold.

18. The control system of claim 16 , wherein the control system is further configured to:
display an electron diffraction image on a graphical user interface, wherein the diffraction image is displayed in association with an image from the region of interest;
receive a user selection of an area of electron diffraction image; and
track an intensity in the selected area over time under specified electron beam conditions to identify a critical threshold.

19. The control system of claim 1 , wherein the control system is further configured to display on a graphical user interface a listing of images of portions of the sample under observation, wherein the listing of images includes images that were previously observed by a user along with an electron dose associated with each listed image.

20. The control system of claim 1 , wherein the control system is further configured to display on a graphical user interface a listing of images of portions of the sample under observation, wherein the listing of images includes images that were collected when the sample under observation was exposed to a pre-defined level of electron radiation from an electron beam of the electron microscope.

Assignees

• Protochips Inc

Inventors

• Walden Ii Franklin Stampley
• Damiano Jr John
• Nackashi David P
• Gardiner Daniel Stephen
• Uebel Mark
• Franks Alan Philip
• Jacobs Benjamin

Classifications

• H04N23/695 Primary

  Control of camera direction for changing a field of view, e.g. pan, tilt or based on tracking of objects · CPC title

• H01J2237/221

  Image processing · CPC title

• G06T7/215

  Motion-based segmentation · CPC title

• G06T7/337

  involving reference images or patches · CPC title

• H01J37/265

  Controlling the tube; circuit arrangements adapted to a particular application not otherwise provided, e.g. bright-field-dark-field illumination · CPC title