Scanning electron microscope and map display method for absorption edge structure

Patent metadata

Field	Value
Publication number	US-12429442-B2
Application number	US-202217941394-A
Country	US
Kind code	B2
Filing date	Sep 9, 2022
Priority date	Sep 10, 2021
Publication date	Sep 30, 2025
Grant date	Sep 30, 2025

Abstract

An electron beam accelerated using a first acceleration voltage is applied to respective positions on a sample to obtain spectra A at the respective positions, and an electron beam accelerated using a second acceleration voltage different from the first acceleration voltage is applied to the respective positions on the sample to obtain spectra B at the respective positions. Then, a spectral ratio A/B of the spectra is calculated at each of the positions to generate a waveform representing the spectral ratio A/B. The value of a spectral ratio A/B in an energy region of interest is extracted from each of the waveforms. The extracted values are mapped onto points corresponding to the respective positions on the sample, whereby a spectral map is generated. The spectral map is displayed.

First claim

The invention claimed is:

1. A scanning electron microscope, comprising:
a detection device; and
an information processing device comprising at least one processor configured to:
apply individual electron beams to an area on a sample using two different acceleration voltages to obtain a spectrum of a soft X-ray in the area on the sample for each of the acceleration voltages;
calculate a spectral ratio of the spectra obtained through application of the electron beams of the two different acceleration voltages;
extract a value of a ratio in an energy region of interest corresponding to energy at an absorption edge of each element from the spectral ratio calculated to provide a plurality of extracted values;
generate a spectral map while changing a position of the energy region of interest by mapping the plurality of extracted values onto points corresponding to respective positions on the sample and adding color to the spectral map based on a magnitude of a value of the plurality of values; and
display the spectral map via a display, wherein an energy band in which a peak of the spectral ratio is measured contains the value of an energy corresponding to the absorption edge.

2. The scanning electron microscope according to claim 1 , wherein the at least one processor is further configured to:
store an energy value at an X-ray absorption edge of an element, wherein, when an energy band of the spectral ratio calculated contains a stored energy value, the at least one processor is configured to:
determine the energy value as the energy region of interest;
extract a ratio at the energy value as a ratio in the energy region of interest; and
display the ratio extracted as the spectral map via the display.

3. The scanning electron microscope according to claim 1 , wherein the at least one processor is further configured to:
calculate the spectral ratio of the spectra while changing an energy band depending on the element.

4. The scanning electron microscope according to claim 2 , wherein the at least one processor is further configured to:
calculate the spectral ratio of the spectra while changing the energy band depending on the element.

5. A method for displaying a map of an absorption edge structure, the method comprising:
applying, by at least one processor of a scanning electron microscope, individual electron beams to an area on a sample, using two different acceleration voltages, to obtain a spectrum of a soft X-ray in the area on the sample for each of the acceleration voltages;
calculating, by the at least one processor of the scanning electron microscope, a spectral ratio of the spectra obtained through application of the electron beams of the two different acceleration voltages;
extracting, by the at least one processor of the scanning electron microscope, a ratio in an energy region of interest corresponding to energy at an absorption edge of each element from the spectral ratio calculated;
generating, by the at least one processor of the scanning electron microscope, a spectral map while changing a position of the energy region of interest by mapping the plurality of extracted values onto points corresponding to respective positions on the sample and adding color to the spectral map based on a magnitude of a value of the plurality of values; and
displaying, by the at least one processor of the scanning electron microscope, the spectral map via a display of the scanning electron microscope, wherein an energy band in which a peak of the spectral ratio is measured contains the value of an energy corresponding to the absorption edge.

Assignees

• Jeol Ltd
• Joel Ltd

Inventors

• Takahashi Hideyuki
• Yokoyama Takaomi

Classifications

• H01J2237/2445

  Photon detectors for X-rays, light, e.g. photomultipliers · CPC title

• H01J37/28 Primary

  with scanning beams {(H01J37/268, H01J37/292, H01J37/2955 take precedence)} · CPC title

• H01J37/244

  Detectors; Associated components or circuits therefor · CPC title

• G06T11/00

  Two-dimensional [2D] image generation · CPC title

• G01N2223/507

  secondary-emission detector · CPC title