Distortion measurement method for electron microscope image, electron microscope, distortion measurement specimen, and method of manufacturing distortion measurement specimen

Patent metadata

Field	Value
Publication number	US-10541111-B2
Application number	US-201815989459-A
Country	US
Kind code	B2
Filing date	May 25, 2018
Priority date	May 26, 2017
Publication date	Jan 21, 2020
Grant date	Jan 21, 2020

Abstract

A distortion measurement method for an electron microscope image includes: loading a distortion measurement specimen having structures arranged in a lattice to a specimen plane of an electron microscope or a plane conjugate to the specimen plane in order to obtain an electron microscope image of the distortion measurement specimen; and measuring a distortion from the obtained electron microscope image of the distortion measurement specimen.

First claim

What is claimed is:

1. A distortion measurement method for an electron microscope image, the method comprising:
loading a distortion measurement specimen having structures arranged in a lattice to a specimen plane of an electron microscope or a plane conjugate to the specimen plane to obtain an electron microscope image of the distortion measurement specimen; and
measuring a distortion from the obtained electron microscope image of the distortion measurement specimen, wherein the distortion comprises changes in an aspect ratio of the obtained electron microscope image;
wherein the step of measuring the distortion comprises:
calculating an auto-correlation function of the electron microscope image of the distortion measurement specimen; and
measuring the distortion based on a pattern formed by connecting peak positions of the auto-correlation function, wherein the pattern is an ellipse.

2. The distortion measurement method according to claim 1 , wherein the ellipse is a concentric ellipse.

3. The distortion measurement method according to claim 1 ,
wherein the distortion measurement specimen comprises:
a substrate; and
a pattern-formed layer supported by the substrate and including the structures,
wherein the structures are at least one of through-holes, projected portions, and recessed portions.

4. An electron microscope configured to measure a distortion of an electron microscope image, the electron microscope comprising:
an image acquiring section that acquires an electron microscope image of a distortion measurement specimen having structures arranged in a lattice;
a distortion measuring section that measures a distortion from the electron microscope image of the distortion measurement specimen, wherein the distortion comprises changes in an aspect ratio of the obtained electron microscope image; and
an auto-correlation function calculating section that calculates an auto-correlation function of the electron microscope image of the distortion measurement specimen;
wherein the distortion measuring section measures the distortion based on a pattern formed by connecting peak positions of the auto-correlation function, wherein the pattern is an ellipse.

5. The electron microscope according to claim 4 , further comprising:
a display control section that performs control to cause a measurement result of the distortion as measured by the distortion measuring section to be displayed on a display section.

6. The electron microscope according to claim 4 , further comprising:
a distortion correcting section that corrects a distortion of a photographed electron microscope image based on a measurement result of the distortion as measured by the distortion measuring section.

7. The electron microscope according to claim 4 , further comprising:
a scanning signal generating section that generates a scanning signal based on a measurement result of the distortion as measured by the distortion measuring section; and
a scanning deflector that scans over a specimen with an electron beam in response to the scanning signal.

8. A distortion measurement specimen for measuring a distortion of an electron microscope image, the distortion measurement specimen comprising:
a substrate;
a pattern-formed layer supported by the substrate and including through-holes arranged in a lattice, wherein the pattern-formed layer is formed on a first surface of the substrate;
a first conductive layer; and
a second conductive layer;
wherein a portion of the pattern-formed layer is sandwiched between the first conductive layer and the second conductive layer, wherein the portion includes the through-holes and the through-holes penetrate the first conductive layer, the pattern-formed layer, and the second conductive layer.

9. A method of manufacturing a distortion measurement specimen for measuring a distortion of an electron microscope image, the method comprising:
preparing a substrate;
forming a first layer on a first surface of the substrate;
forming structures arranged in a lattice by patterning the first layer;
etching a second surface on an opposite side to the first surface of the substrate to remove the substrate;
forming a first conductive layer on an upper surface of the first layer, wherein the first conductive layer comprises a conductive material; and
forming a second conductive layer on a lower surface of the first layer, wherein the first conductive layer comprises a conductive material.

10. The method of manufacturing the distortion measurement specimen according to claim 9 ,
wherein, in the step of forming structures, a resist for patterning the first layer is exposed by an electron-beam lithography system.

11. The method of manufacturing the distortion measurement specimen according to claim 10 ,
wherein, in the step of forming structures, etching of the first layer is performed by using an inductively-coupled plasma etching device.

12. The method of manufacturing the distortion measurement specimen according to claim 9 ,
wherein, in the step of forming the first layer, the first layer is formed so that the first layer is imparted with tensile stress.

13. The method of manufacturing a distortion measurement specimen according to claim 9 ,
wherein the structures are at least one of through-holes, projected portions, and recessed portions, and
wherein a shape of the structures as viewed from a thickness direction of the first layer is a circle.

14. A distortion measurement method for an electron microscope image, the method comprising:
measuring a distortion of an electron microscope image by using an electron microscope image of a distortion measurement specimen, wherein the distortion measurement specimen comprises:
a substrate, and
a pattern-formed layer supported by the substrate and including structures arranged in a lattice;

calculating an auto-correlation function of the electron microscope image of the distortion measurement specimen; and
measuring the distortion based on a pattern formed by connecting peak positions of the auto-correlation function, wherein the pattern is an ellipse.

Assignees

• Jeol Ltd

Inventors

• Konyuba Yuji
• Omoto Kazuya
• Sawada Hidetaka

Classifications

• H01J37/265

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

• H01J2237/2826

  Calibration · CPC title

• H01J37/263

  Contrast, resolution or power of penetration · CPC title

• H01J2237/1536

  Image distortions due to scanning · CPC title

• H01J2237/2802

  Transmission microscopes · CPC title