Charged particle microscope apparatus and image acquisition method of charged particle microscope apparatus utilizing image correction based on estimated diffusion of charged particles

1. A charged particle microscope apparatus, comprising:

a radiation optical system that radiates a focused charged particle beam to an upper side of a sample provided with a pattern and scans the sample with the charged particle beam, the sample having a laminate structure including a plurality of layers;

a detection optical system that detects charged particles generated from the sample to which the charged particle beam has been radiated by the radiation optical system; and

a processing unit that:

processes the charged particles detected by the detection optical system to obtain a charged particle image of the sample,

estimates diffusion of the charged particles at any depth of the pattern of the sample based on the laminate structure of the sample, a material of each layer and a thickness of each layer, and information on radiation energy of the charged particle beam in the radiation optical system,

corrects the obtained charged particle image using the estimated diffusion of the charged particles, and

processes the corrected charged particle image.

2. The charged particle microscope apparatus according to claim 1 , wherein:

the processing unit executes any one of processes of detecting defects of the pattern on the sample, classifying the defects of the pattern on the sample, measuring dimensions of the pattern on the sample, and measuring a shape of the pattern on the sample, using the corrected charged particle image.

3. The charged particle microscope apparatus according to claim 1 , wherein:

in the processing unit, the diffusion of the charged particles at any depth of the pattern of the sample is estimated on the basis of the depth of the pattern of the sample.

4. The charged particle microscope apparatus according to claim 1 , wherein:

in the processing unit, pattern dimension measurement is executed on a first image and a second image, the first image being the corrected charged particle image and the second image being the charged particle image before the correction,

a difference between a pattern dimension measurement result of the first image and a pattern dimension measurement result of the second image is set as a measurement error, and

the charged particle image of the sample obtained by processing the charged particles detected by the detection optical system is corrected using the measurement error, when the pattern is measured.

5. The charged particle microscope apparatus according to claim 1 , wherein:

imaging conditions of the charged particle beam in the radiation optical system are conditions where an information amount is maximized, using a model of a characteristic of scattering of the charged particles in a solid and an emission characteristic of the charged particles.

6. An image acquisition method of a charged particle microscope apparatus, comprising:

radiating a focused charged particle beam to an upper side of a sample provided with a pattern and scanning the sample with the charged particle beam, the sample having a laminate structure including a plurality of layers;

detecting charged particles generated from the radiated sample;

processing the detected charged particles to obtain a charged particle image of the sample;

estimating diffusion of the charged particles at any depth of the pattern of the sample based on the laminate structure of the sample, a material of each layer and a thickness of each layer, and radiation energy of the charged particle beam;

correcting the obtained charged particle image using the estimated diffusion of the charged particles, and

processing the corrected charged particle image.

7. The image acquisition method according to claim 6 , further comprising:

using the corrected charged particle image for detecting defects of the pattern on the sample, classifying the defects of the pattern on the sample, measuring dimensions of the pattern on the sample, or measuring a shape of the pattern on the sample.

8. The image acquisition method according to claim 6 , wherein:

the diffusion of the charged particles at any depth of the pattern of the sample is estimated on the basis of a depth of the pattern of the sample.

9. The image acquisition method according to claim 6 , wherein:

pattern dimension measurement is executed on a first image and a second image, the first image being the corrected charged particle image and the second image being the charged particle image before the correction,

a difference between a pattern dimension measurement result of the first image and a pattern dimension measurement result of the second image is set as a measurement error, and

the charged particle image of the sample obtained by processing the detected charged particles is corrected using the measurement error, when the pattern is measured.

10. The image acquisition method according to claim 6 , wherein:

imaging conditions of the radiated charged particle beam are conditions where an information amount is maximized, using a model of a characteristic of scattering of the charged particles in a solid and an emission characteristic of the charged particles.