# US 2019/0378685 A1 · Charged Particle Beam Apparatus, and Method of Adjusting Charged Particle Beam Apparatus

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- Number: US 2019/0378685 A1
- Document ID: US20190378685A1
- Status: Published application
- Kind: A1
- Application number: 16/487,551
- Filed: 2017-03-24
- Published: 2019-12-12
- Earliest claimed: 2017-03-24
- Assignees: Hitachi High-Technologies Corporation
- Applicants: Hitachi High-Technologies Corporation
- Inventors: Masaki HASEGAWA; Tomohiko OGATA; Noriyuki KANEOKA; Hisaya MURAKOSHI; Katsunori ONUKI
- Web page: https://patentgrep.com/patent/US20190378685A1

## CPC

- H01J 37/265: {Controlling the tube; circuit arrangements adapted to a particular application not otherwise provided, e.g. bright-field-dark-field illumination}
- H01J 37/29: Reflection microscopes
- H01J 37/20: Means for supporting or positioning the object or the material; Means for adjusting diaphragms or lenses associated with the support
- H01J 37/21: Means for adjusting the focus
- H01J 37/12: electrostatic
- H01J 37/14: magnetic
- H01J 37/263: {Contrast, resolution or power of penetration}
- H01J 2237/0048: Charging arrangements
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)

## Abstract

A purpose of the present invention is to provide a charged particle beam apparatus that performs apparatus adjustment based on a proper evaluation of a beam. To achieve the abovementioned purpose, with the present invention, proposed is a charged particle beam apparatus comprising: an irradiation optical system including a lens for converging charged particle beams emitted from a charged particle source; and an imaging optical system for imaging the charged particles obtained by irradiating the charged particle beams toward a sample on an imaging element, wherein the charged particle beam apparatus comprises a control apparatus for controlling the lens, and the control apparatus evaluates for each lens condition the size of a specific brightness area obtained by the charged particle beam being made to reach the sample, and selects the lens condition for which the size information fulfills a designated condition.

## Claims

### Claim 1

A charged particle beam apparatus comprising:
an irradiation optical system including a lens which is configured to converge charged particle beams emitted from a charged particle source;
an imaging optical system which is configured to image charged particles obtained by irradiating a sample with the charged particle beams on an imaging element; and
a control apparatus which is configured to control the lens, wherein
the control apparatus is configured to evaluate for each lens condition a size of a specific brightness area obtained by the charged particle beams being made to reach the sample, and to select a lens condition under which the size information fulfills a designated condition.

### Claim 2 (depends on 1)

The charged particle beam apparatus according to claim 1, further comprising:
a negative voltage application power supply which is configured to apply a negative voltage to the sample, wherein
the control apparatus is configured to control the negative voltage application power supply so as to switch the irradiation charged particle beams from the irradiation optical system between a state of being reflected without reaching the sample and a state of reaching the sample, and the control apparatus is configured to select a lens condition under which the size of the specific brightness area appearing in a state in which the charged particle beams are switched to the state of reaching the sample fulfills a designated condition.

### Claim 3 (depends on 1)

The charged particle beam apparatus according to claim 1, wherein
the control apparatus is configured to select a lens condition under which the size of the specific area is maximum or equal to or greater than a designated value.

### Claim 4 (depends on 3)

The charged particle beam apparatus according to claim 3, further comprising:
a negative voltage application power supply which is configured to apply a negative voltage to the sample, wherein
the control apparatus is configured to select a lens condition under which the size of the specific area when the negative voltage applied to the sample from the negative voltage application power supply is changed to a positive side is maximum or equal to or greater than the designated value.

### Claim 5 (depends on 1)

The charged particle beam apparatus according to claim 1, further comprising:
a negative voltage application power supply which is configured to apply a negative voltage to the sample, wherein
the control apparatus is configured to set the lens to a plurality of conditions, and to obtain a change in the size of the specific brightness area when the voltage applied to the sample is changed under each of the plurality of conditions.

### Claim 6 (depends on 5)

The charged particle beam apparatus according to claim 5, wherein
the control apparatus is configured to select a lens condition under which the change in the size of the specific brightness area is minimum or equal to or greater than a designated value.

### Claim 7

A charged particle beam apparatus comprising:
an irradiation optical system including an optical element which is configured to adjust charged particle beams emitted from a charged particle source;
an imaging optical system which is configured to image charged particles obtained by irradiating a sample with the charged particle beams on an imaging element;
an image processing apparatus which is configured to generate an image based on the charged particles detected by the imaging element;
a negative voltage application power supply which is configured to apply a negative voltage to the sample; and
a control apparatus which is configured to control the negative voltage application power supply, wherein
the control apparatus is configured to control the negative voltage application power supply so as to switch the irradiation charged particle beams from the irradiation optical system between a state of being reflected without reaching the sample and a state of reaching the sample, and the control apparatus is configured to obtain at least one of a size and a position of a specific brightness area based on detection of the charged particles reaching the imaging element in a state in which the charged particle beams are switched to the state of reaching the sample, and to adjust the optical element such that at least one of the size and the position of the specific brightness area satisfies a designated condition.

### Claim 8 (depends on 7)

The charged particle beam apparatus according to claim 7, wherein
the control apparatus is configured to control the optical element such that a center of the specific brightness area coincides with a center of the image generated by the image processing apparatus.

### Claim 9

A method of adjusting a charged particle beam apparatus including: an irradiation optical system including an optical element which is configured to adjust charged particle beams emitted from a charged particle source, and an imaging optical system which is configured to image on an imaging element charged particles obtained by irradiating a sample with the charged particle beams, the method comprising:
applying a negative voltage to the sample such that the charged particle beams are brought into a state of reaching the sample;
detecting charged particles obtained in the negative voltage application state by the imaging element;
generating an image including a specific brightness area that shows a reaching area of the charged particle beams based on the detection of the charged particles; and
adjusting the optical element such that a size and a position of the specific brightness area contained in the image fulfill a designated condition.

### Claim 10 (depends on 9)

The method of adjusting a charged particle beam apparatus according to claim 9, wherein
the optical element is a lens, and a lens condition is adjusted such that the size of the specific brightness area is the largest or is a size equal to or greater than a designated value.

### Claim 11 (depends on 9)

The method of adjusting a charged particle beam apparatus according to claim 9, wherein
the optical element is a deflector which is configured to perform axis alignment of the charged particle beams with an ideal optical axis of a lens that converges the charged particle beams, and the deflector is adjusted such that a center of the specific brightness area coincides with a center of the image.
