Charged Particle Beam Device and Charged Particle Beam Device Control Method

• US 20160203947A1
• Filed: 10/07/2014
• Published: 07/14/2016
• Est. Priority Date: 10/08/2013
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: SAITOU, Tsutomu, HOSOYA, Kotaro, AOKI, Kenji, NAKAMURA, Mitsuhiro, SHIGETO, Kunji
• Granted Patent: US 9,881,769 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01J 2237/18 Vacuum control means
• CPC Class Codes: H01J 2237/24465 Sectored detectors, e.g. quadrants
• CPC Class Codes: H01J 2237/24475 Scattered electron detectors
• CPC Class Codes: H01J 2237/24495 Signal processing, e.g. mixing of two or more signals
• CPC Class Codes: H01J 2237/248 Components associated with the control of the tube
• CPC Class Codes: H01J 2237/2809 characterised by the imaging problems involved
• CPC Class Codes: H01J 37/073 Electron guns using field emission, photo emission, or secondary emission electron sources
• CPC Class Codes: H01J 37/244 Detectors; Associated components or circuits therefor
• CPC Class Codes: H01J 37/28 with scanning beams H01J37/268, H01J37/292, H01J37/2955 take precedence
• CPC Class Codes: H01J 37/292 using scanning ray

Abstract

The objective of the present invention is to provide a charged particle beam device, wherein the positional relationship between reflected electron detection elements and a sample and the vacuum state of the sample surroundings are evaluated to select automatically a reflected electron detection element appropriate for acquiring an intended image. In this charged particle beam device, all the reflected electron detection elements are selected when the degree of vacuum inside the sample chamber is high and the sample is distant from the reflected electron detectors, while a reflected electron detection element appropriate for acquiring a compositional image or a height map image is selected when the degree of vacuum inside the sample chamber is high and the sample is close to the reflected electron detectors. When the degree of vacuum inside the sample chamber is low, all the reflected electron detection elements are selected.

Claims

1-18. -18. (canceled)

19. A charged particle beam device irradiating a charged particle beam to a sample, the charged particle beam device comprising:

a charged particle beam source configured to emit a charged particle beam;

a sample moving device configured to move a position of the sample;

a reflected electron detector having a plurality of detection elements configured to detect, by irradiating the charged particle beam to the sample, a reflected electron generated from the sample;

a signal control circuit configured to select, from among the detection elements that the reflected electron detector has, a detection element to be used;

a pressure meter configured to measure an atmospheric pressure inside a sample chamber where the sample is disposed; and

an exhaust system configured to vacuum exhaust the inside of the sample chamber, wherein

a plurality of the detection elements are disposed along a concentric ring;

when the atmospheric pressure inside the sample chamber is smaller than a predetermined atmospheric pressure threshold value and a distance between the sample and the reflected electron detector along an irradiation axis of the charged particle beam is greater than or equal to a predetermined distance threshold value, the signal control circuit selects all of the detection elements; and

when the atmospheric pressure inside the sample chamber is smaller than the predetermined atmospheric pressure threshold value and the distance is smaller than the predetermined distance threshold value, the signal control circuit selects at least one of the detection elements other than the detection element disposed along the concentric ring on an innermost circumference side or at least one of the detection elements other than the detection element disposed along the concentric ring on an outermost circumference side.

20. The charged particle beam device according to claim 19 further comprising:

an operation device configured to generate an observation image of the sample using a detection signal of the reflection electron; and

a user interface configured to instruct generation of a compositional image where an atomic composition of the sample is emphasized or generation of an unevenness image where an uneven shape of the sample is emphasized, wherein

when an instruction to generate the compositional image is input via the user interface, and the atmospheric pressure inside the sample chamber is smaller than the predetermined atmospheric pressure threshold value and the distance is smaller than the predetermined distance threshold value, the signal control circuit selects at least one of the detection elements other than the detection element disposed along the concentric ring on the outermost circumference side; and

when an instruction to generate the unevenness image is input via the user interface, and the atmospheric pressure inside the sample chamber is smaller than the predetermined atmospheric pressure threshold value and the distance is smaller than the predetermined distance threshold value, the signal control circuit selects at least one of the detection elements other than the detection element disposed along the concentric ring on the innermost circumference side.

21. The charged particle beam device according to claim 20, wherein

when the atmospheric pressure inside the sample chamber is greater than or equal to the predetermined atmospheric pressure threshold value, the signal control circuit selects all of the detection elements without respect to the distance.

22. The charged particle beam device according to claim 20, wherein

the user interface comprises an input unit configured to instruct which of the detection elements is to be selected;

and

when the detection element to be selected is selected via the user interface, the signal control circuit selects the detection element to be selected in accordance with the instruction.

23. The charged particle beam device according to claim 19, wherein

the detection element is formed by a plurality of the fan-shaped detection elements along the concentric ring.

24. The charged particle beam device according to claim 19, wherein

the detection element is formed by disposing, along the concentric ring, the detection elements with a tapered shape, which are tapered toward a center of the concentric ring.

25. The charged particle beam device according to claim 19, wherein

the detection element is formed by disposing, along the concentric ring, the detection elements with a tapered shape, which are tapered from the center of the concentric ring to an outer circumference.

26. A charged particle beam device irradiating a charged particle beam to a sample, the charged particle beam device comprising:

a charged particle beam source configured to emit a charged particle beam;

a sample moving device configured to move a position of the sample;

a reflected electron detector having a plurality of detection elements configured to detect, by irradiating the charged particle beam to the sample, a reflected electron generated from the sample;

a signal control circuit configured to select, from among the detection elements that the reflected electron detector has, a detection element to be used;

a pressure meter configured to measure an atmospheric pressure inside a sample chamber where the sample is disposed; and

an exhaust system configured to vacuum exhaust inside the sample chamber, wherein

a plurality of the detection elements are disposed along a concentric ring; and

when the atmospheric pressure inside the sample chamber is greater than or equal to a predetermined atmospheric pressure threshold value, the signal control circuit selects all of the detection elements without respect to a distance between the sample and the reflected electron detector along an irradiation axis of the charged particle beam.

27. The charged particle beam device according to claim 26, wherein

when the atmospheric pressure inside of the sample chamber is smaller than the predetermined atmospheric pressure threshold value and the distance is greater than or equal to a predetermined distance threshold value, the signal control circuit selects all of the detection elements;

and

when the atmospheric pressure inside the sample chamber is smaller than the predetermined atmospheric pressure threshold value and the distance is smaller than the predetermined distance threshold value, the signal control circuit selects at least one of the detection elements other than the detection element disposed along the concentric ring on an innermost circumference side or at least one of the detection elements other than the detection element disposed along the concentric ring on an outermost circumference side.

28. The charged particle beam device according to claim 27 further comprising:

an operation device configured to generate an observation image of the sample using a detection signal of the reflection electron; and

a user interface configured to instruct generation of a compositional image where an atomic composition of the sample is emphasized or generation of an unevenness image where an uneven shape of the sample is emphasized, wherein

when an instruction to generate the compositional image is input via the user interface, and the atmospheric pressure inside the sample chamber is smaller than the predetermined atmospheric pressure threshold value and the distance is smaller than the predetermined distance threshold value, the signal control circuit selects at least one of the detection elements other than the detection elements disposed along the concentric ring on the outermost circumference side; and

when an instruction to generate the unevenness image is input via the user interface, and the atmospheric pressure inside the sample chamber is smaller than the predetermined atmospheric pressure threshold value and the distance is smaller than the predetermined distance threshold value, the signal control circuit selects at least one of the detection elements other than the detection elements disposed along the concentric ring on the innermost circumference side.

29. The charged particle beam device according to claim 28, wherein

the user interface comprises an input unit configured to instruct which of the detection elements is to be selected;

and

when the detection element to be selected is selected via the user interface, the signal control circuit selects the detection element to be selected in accordance with the instruction.

30. The charged particle beam device according to claim 26, wherein

the detection element is formed by a plurality of the fan-shaped detection elements along the concentric ring.

31. The charged particle beam device according to claim 26, wherein

the detection element is formed by disposing, along the concentric ring, the detection elements with a tapered shape, which are tapered toward a center of the concentric ring.

32. The charged particle beam device according to claim 26, wherein

the detection element is formed by disposing, along the concentric ring, the detection elements with a tapered shape, which are tapered from the center of the concentric ring to an outer circumference.

33. A method of controlling a charged particle beam device irradiating a charged particle beam to a sample,

the charged particle beam device comprising;

a charged particle beam source configured to emit a charged particle beam;

a sample moving device configured to move a position of the sample;

a reflected electron detector having a plurality of detection elements configured to detect, by irradiating the charged particle beam to the sample, a reflected electron generated from the sample;

a pressure meter configured to measure an atmospheric pressure inside a sample chamber where the sample is disposed; and

an exhaust system configured to vacuum exhaust the inside of the sample chamber,

a plurality of the detection elements disposed along a concentric ring,

the method comprising a signal control step of selecting, from among the detection elements that the reflected electron detector has, a detection element to be used, wherein

in the signal control step,

when the atmospheric pressure inside the sample chamber is smaller than a predetermined atmospheric pressure threshold value and a distance between the sample and the reflected electron detector along an irradiation axis of the charged particle beam is greater than or equal to a predetermined distance threshold value, all of the detection elements are selected; and

when the atmospheric pressure inside the sample chamber is smaller than the predetermined atmospheric pressure threshold value and the distance is smaller than the predetermined distance threshold value, at least one of the detection elements other than the detection elements disposed along the concentric ring on an innermost circumference side or at least one of the detection elements other than the detection elements disposed along the concentric ring on an outermost circumference side is selected.

34. A method of controlling a charged particle beam device irradiating a charged particle beam to a sample,

the charged particle beam device comprising;

a charged particle beam source configured to emit a charged particle beam;

a sample moving device configured to move a position of the sample;

a reflected electron detector having a plurality of detection elements configured to detect, by irradiating the charged particle beam to the sample, a reflected electron generated from the sample;

a pressure meter configured to measure an atmospheric pressure inside a sample chamber where the sample is disposed; and

an exhaust system configured to vacuum exhaust the inside of the sample chamber,

a plurality of the detection elements disposed along a concentric ring,

the method comprising a signal control step of selecting, from among the detection elements that the reflected electron detector has, a detection element to be used, wherein

in the signal control step, when the atmospheric pressure inside the sample chamber is greater than or equal to a predetermined atmospheric pressure threshold value, all of the detection elements are selected without respect to a distance between the sample and the reflected electron detector along an irradiation axis of the charged particle beam.