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

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.