AFM imaging with metrology-preserving real time denoising

Patent metadata

Field	Value
Publication number	US-11796565-B2
Application number	US-202117226970-A
Country	US
Kind code	B2
Filing date	Apr 9, 2021
Priority date	Apr 9, 2021
Publication date	Oct 24, 2023
Grant date	Oct 24, 2023

Abstract

A method of operating an atomic force microscope (AFM), using a denoising algorithm, real-time, during AFM data acquisition. Total Variation and Non-Local Means denoising are preferred. Real time images with minimized sensor noise needing no post-image acquisition processing to account for noise as described herein results.

First claim

We claim:

1. A method of atomic force microscopy (AFM), the method comprising:
engaging a probe of the AFM with a surface of a sample;
oscillating the probe in a mode of AFM operation;
measuring system noise to generate a noise image;
providing relative scanning motion between the probe and sample;
measuring the deflection of the probe in response to the providing step and controlling the probe-sample separation according to the mode of AFM operation for a selected number of scan lines to generate a sample image for the selected number of scan lines;
denoising the sample image in real time using the system noise;
measuring the deflection for the next line of the scanning motion to generate a new sample image; and
denoising the new sample image in real time using the system noise.

2. The method of claim 1 , wherein the selected number is at least two.

3. The method of claim 2 , wherein the selected number is at least five, and the denoised sample image line is of the middle of the selected number.

4. The method of claim 3 , wherein the denoising step includes using a Non-local Means (NLM) denoising algorithm.

5. The method of claim 1 , wherein the denoising step includes using a Total Variation (TV) denoising algorithm.

6. The method of claim 1 , wherein the scanning motion is a raster scan.

7. The method of claim 1 , further comprising repeating all the steps after and including the denoising step until a region of interest of the sample is imaged.

8. The method of claim 1 , wherein the mode is one of peak force tapping (PFT) mode, contact mode and tapping mode.

9. The method of claim 1 , further comprising applying one of a low-pass kernel and a deconvolution kernel to the denoised image.

10. An atomic force microscope (AFM) comprising:
a scanner that provides relative scanning motion between a probe of the AFM and a sample;
a detector that measures the deflection of the probe in response to probe-sample interaction during AFM operation, the deflection being indicative of a sample property and stored as an image; and
a controller that implements a denoising algorithm to denoise the image of a selected number of scan lines in real time during AFM operation.

11. The AFM of claim 10 , wherein the selected number is at least two scan lines.

12. The AFM of claim 11 , wherein the selected number is at least five scan lines and the denoised image is the middle of the at least five scan lines.

13. The AFM of claim 10 , wherein the denoising algorithm is one of Total Variation (TV) denoising, and Non-local Means (NLM) denoising.

14. The AFM of claim 10 , wherein the controller implements one of a low-pass Kernel and a deconvolution kernel to the denoised image to minimize an affect of an offset between a trace and re-trace AFM imaging operation.

15. The method of claim 12 , wherein the AFM is operated in one of peak force tapping (PFT) mode, contact mode and tapping mode.

Assignees

• Bruker Nano Inc

Inventors

• Fonoberov Vladimir
• Young James
• Osborne Jason
• Hand Sean

Classifications

• G01Q30/06 Primary

  for error compensation · CPC title

• G01Q60/24

  AFM [Atomic Force Microscopy] or apparatus therefor, e.g. AFM probes · CPC title

• G06T5/002

  Physics · mapped topic

• G06T5/20

  using local operators · CPC title

• G06T5/50

  using two or more images, e.g. averaging or subtraction · CPC title