Sample observation device and sample observation method

Patent metadata

Field	Value
Publication number	US-10559074-B2
Application number	US-201815898366-A
Country	US
Kind code	B2
Filing date	Feb 16, 2018
Priority date	Feb 20, 2017
Publication date	Feb 11, 2020
Grant date	Feb 11, 2020

Abstract

A sample observation device images a sample placed on a movable table by irradiating and scanning the sample with a charged particle beam of a microscope. A degraded image having poor image quality and a high quality image having satisfactory image quality which are acquired at the same location of the sample by causing the charged particle microscope to change an imaging condition for imaging the sample are stored. An estimation process parameter is calculated for estimating the high quality image from the degraded image by using the stored degraded image and high quality image. A high quality image estimation unit processes the degraded image obtained by causing the charged particle microscope to image the desired site of the sample by using the calculated estimation process parameter. Thereby, the high quality image obtained at the desired site is estimated, and then the estimated high quality image is output.

First claim

What is claimed is:

1. A sample observation device comprising:
a charged particle microscope that images a sample placed on a movable table by irradiating and scanning the sample with a charged particle beam;
an image storage device configured to store a degraded first image having poor image quality and a high quality second image having satisfactory image quality which are obtained at a same first location of the sample, wherein the degraded first image is imaged by the charged particle microscope with first imaging conditions and the high quality second image is imaged by the charged particle microscope with second imaging conditions different from the first imaging conditions; and
a processor programmed to:
calculate an estimation process parameter for estimating the high quality second image from the degraded first image by using the degraded first image and the high quality second image which are stored in the image storage device,
obtain a degraded third image at a desired second location of the sample and which is imaged by the charged particle microscope with the first imaging conditions, and
estimate a high quality fourth image of the desired second location by using the calculated estimation process parameter and the degraded third image.

2. The sample observation device according to claim 1 ,
wherein the processor is programmed to:
calculate a difference between the high quality second image estimated using the calculated estimation process parameter from the degraded first image and the high quality second image captured by imaging the same first location of the sample, as an error, and
store the calculated estimation process parameter when the difference is smaller than a predetermined threshold value.

3. The sample observation device according to claim 1 , wherein the processor is programmed to:
store the first and second imaging conditions,
wherein the first imaging conditions include at least one of a number of added frames, an image resolution, a focus height of the charged particle beam of the charged particle microscope with respect to a surface of the sample, and a time required from when the sample stops moving until the charged particle microscope starts to observe the sample.

4. The sample observation device according to claim 1 ,
wherein, when the high quality fourth image is being estimated, the charged particle microscope moves a position of the table on which the sample is placed so that the second location of the sample exits and a third location of the sample enters a visual field of the charged particle microscope.

5. A sample observation device comprising:
a charged particle microscope that images a sample placed on a movable table by irradiating and scanning the sample with a charged particle beam;
an image storage device that stores a low magnification first image obtained by imaging a first location of the sample at low magnification by the charged particle microscope, and a high quality second image obtained by imaging a region of the same first location of the sample at high magnification by the charged particle microscope; and
a processor programmed to:
generate an enlarged image of the region, corresponding to the high quality second image, in the low magnification first image stored in the image storage device,
calculate an estimation process parameter for estimating an image corresponding to the high quality second image from the enlarged image,
obtain a low magnification third image by imaging a desired second location of the sample at low magnification by the charged particle microscope, and
estimate a high quality fourth image of a partial region of the second location by using the calculated estimation parameter and the low magnification third image.

6. The sample observation device according to claim 5 ,
wherein the processor is programmed to:
calculate a difference between the high quality second image estimated using the calculated estimation process parameter from the degraded first image and the high quality second image obtained by imagine the region of the same first location of the sample at high magnification by the charged particle microscope, as an error, and
store the calculated estimation process parameter when the error is smaller than a predetermined threshold value.

7. The sample observation device according to claim 5 , wherein the processor is programmed to:
detect a defect of the sample from the low magnification first image obtained by imaging the sample at the low magnification,
wherein the high quality second image obtained by imaging the region of the same first location of the sample at high magnification by the charged particle microscope includes the detected defect.

8. The sample observation device according to claim 5 ,
wherein, when the high quality fourth image is being estimated, the charged particle microscope moves a position of the table on which the sample is placed so that the second location exits and a third location of the sample enters a visual field of the charged particle microscope.

9. A sample observation method of observing a sample by using a charged particle microscope, the method comprising:
imaging the sample placed on a movable table by the charged particle microscope;
storing, in an image storage device, a degraded first image having poor image quality and a high quality second image having satisfactory image quality which are obtained at a same first location of the sample, wherein the degraded first image is imaged by the charged particle microscope with first imaging conditions and the high quality second image is imaged by the charged particle microscope with second imaging conditions different from the first imagine conditions;
calculating an estimation process parameter for estimating the high quality second image from the degraded first image by using the degraded first image and the high quality second image which are stored in the image storage device;
obtaining a degraded third image obtained at a desired second location of the sample and which is imaged by the charged particle microscope with the first imagine conditions;
estimating a high quality fourth image of the desired second location by using the calculated estimation process parameter and the degraded third image; and
outputting the estimated high quality fourth image.

10. The sample observation method according to claim 9 , further comprising:
a difference between the high quality second image estimated using the calculated estimation process parameter from the degraded first image and the high quality second image captured by imaging the same first location of the sample, as an error; and
storing the calculated estimation process parameter when the error is smaller than a predetermined threshold value.

11. The sample observation method according to claim 9 ,
wherein the first imaging conditions include at least one of a number of added frames, an image resolution, a focus height of the charged particle beam of the charged particle microscope with respect to a surface of the sample, and a time required from when the sample stops moving until the charged particle microscope starts to observe the sample.

12. The sample observation method according to claim 9 ,
wherein, when the high quality fourth image is being estimated, the charged particle microscope moves a position of the table on which the sample is placed so that the second location exits and a third location of the sample enters a visual field of the charged particle microscope.

13. A sample observation method of observing a sample by using a charged particle microscope, the method compris

Assignees

• Hitachi High Tech Corp

Inventors

• Harada Minoru
• Takagi Yuji
• Kondo Naoaki
• Hirai Takehiro

Classifications

• G06T2207/20084

  Artificial neural networks [ANN] · CPC title

• G06T2207/20081

  Training; Learning · CPC title

• G06T7/001

  using an image reference approach · CPC title

• H01J2237/221

  Image processing · CPC title

• G06T2207/10016

  Video; Image sequence · CPC title