Method for creating electron-beam hologram, magnetic field information measurement method and magnetic field information measuring device

Patent metadata

Field	Value
Publication number	US-11067649-B2
Application number	US-201816477974-A
Country	US
Kind code	B2
Filing date	Jan 12, 2018
Priority date	Jan 24, 2017
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

An object wave made of an electron beam influenced by a sample and reference beam made of an electron beam not influenced by the sample are made to interfere with each other where a magnetic field has been applied to the sample to create a first electron-beam hologram and create a first reconstructed phase image from the first electron-beam hologram. An object wave made of an electron beam influenced by the sample and a reference beam made of an electron beam not influenced by the sample are made to interfere where a magnetic field has not been applied to the sample to create a second electron-beam hologram and create a second reconstructed phase image from the second electron-beam hologram. Magnetic field information indicating the influence of the magnetic field on the sample is acquired on the basis of the difference between the first and second reconstructed phase images.

First claim

What is claimed is:

1. A magnetic field information measurement method comprising:
a first reconstructed phase image creation step of creating a first reconstructed phase image from a first electron-beam hologram that is created by causing an object wave comprised of an electron beam that is influenced by a sample and a reference wave comprised of an electron beam that is not influenced by the sample to interfere with each other under a state where a magnetic field has been applied to the sample;
a second reconstructed phase image creation step of creating a second reconstructed phase image from a second electron-beam hologram that is created by causing an object wave comprised of an electron beam that is influenced by a sample and a reference wave comprised of an electron beam that is not influenced by the sample to interfere with each other under a state where a magnetic field has not been applied to the sample; and
a magnetic field information acquisition step of obtaining magnetic field information indicating influence of the magnetic field on the sample on the basis of a difference between the first reconstructed phase image and the second reconstructed phase image, wherein:
the sample includes a material that emits secondary electrons when irradiated with an electron beam;
in the first reconstructed phase image creation step and the second reconstructed phase image creation step, the sample is irradiated with an electron beam to emit secondary electrons from the sample and the electron beam that passes through the sample is made to interfere with the reference wave as the object wave; and
in the magnetic field information acquisition step, information indicating the influence of the magnetic field on the secondary electrons emitted from the sample is acquired as the magnetic field information.

2. The magnetic field information measurement method according to claim 1 , wherein the sample is made of an insulating material.

3. A magnetic field information measuring device comprising:
electron-beam hologram creation means provided to create an electron-beam hologram by causing an object wave comprised of an electron beam that is influenced by a sample and a reference wave comprised of an electron beam that is not influenced by the sample to interfere with each other;
magnetic field application means provided to apply a magnetic field to the sample; and
magnetic field information acquisition means provided to:
create a first reconstructed phase image from a first electron-beam hologram that is created using the electron-beam hologram creation means under a state where a magnetic field has been applied to the sample using the magnetic field application means,
create a second reconstructed phase image from a second electron-beam hologram that is created using the electron-beam hologram creation means under a state where a magnetic field is not applied to the sample, and
determine the difference between the first reconstructed phase image and the second reconstructed phase image to acquire magnetic field information indicating influence of the magnetic field on the sample, wherein:

the sample includes a material that emits secondary electrons when irradiated with an electron beam;
in the creation of the first reconstructed phase image and the creation of the second reconstructed phase image, the sample is irradiated with an electron beam to emit secondary electrons from the sample and the electron beam that passes through the sample is made to interfere with the reference wave as the object wave; and
the magnetic field information acquisition means acquires information indicating the influence of the magnetic field on the secondary electrons emitted from the sample, as the magnetic field information.

4. The magnetic field information measurement method according to claim 1 , wherein, in the magnetic field information acquisition step, information indicating a spin movement of electrons in the sample or the secondary electrons emitted from the sample is acquired as the magnetic field information.

5. The magnetic field information measurement method according to claim 2 , wherein, in the magnetic field information acquisition step, information indicating a spin movement of electrons in the sample or the secondary electrons emitted from the sample is acquired as the magnetic field information.

6. The magnetic field information measuring device according to claim 3 , wherein the sample is made of an insulating material.

7. The magnetic field information measuring device according to claim 3 , wherein the magnetic field information acquisition means acquires information indicating a spin movement of electrons in the sample or the secondary electrons emitted from the sample, as the magnetic field information.

8. The magnetic field information measuring device according to claim 6 , wherein the magnetic field information acquisition means acquires information indicating a spin movement of electrons in the sample or the secondary electrons emitted from the sample, as the magnetic field information.

Assignees

• Univ Tohoku

Inventors

• Shindo Daisuke
• Sato Takafumi

Classifications

• G01R33/032

  using magneto-optic devices, e.g. Faraday {or Cotton-Mouton effect} · CPC title

• G01R33/1284 Primary

  Spin resolved measurements; Influencing spins during measurements, e.g. in spintronics devices · CPC title

• G01N23/2251

  using incident electron beams, e.g. scanning electron microscopy [SEM] · CPC title

• G03H5/00

  Holographic processes or apparatus using particles or using waves other than those covered by groups G03H1/00 or G03H3/00 for obtaining holograms; Processes or apparatus for obtaining an optical image from them (G03H1/22 takes precedence; construction of electron microscopes H01J37/26; {investigating or analysing materials by the use of microwaves G01N22/00, by the use of particles wave or X-rays G01N23/00, G21K7/00}) · CPC title

• H01J37/266

  Measurement of magnetic or electric fields in the object; Lorentzmicroscopy (spot analysing H01J37/252; emission microscopes H01J37/285; reflecting microscopes H01J37/29) · CPC title