Height Measurement Device and Charged Particle Beam Device

• US 20170343340A1
• Filed: 12/10/2014
• Published: 11/30/2017
• Est. Priority Date: 12/10/2014
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: KAWADA, Hiroki, FUKUDA, Muneyuki, MOMONOI, Yoshinori, TAKAMI, Shou
• Granted Patent: US 10,101,150 B2
• Time in Patent Office: Days
• CPC Class Codes: G01B 15/00 Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons characterised by the use of optical techniques G01B9/00, G01B11/00
• CPC Class Codes: G01B 15/02 for measuring thickness
• CPC Class Codes: G01B 2210/56 Measuring geometric parameters of semiconductor structures, e.g. profile, critical dimensions or trench depth
• CPC Class Codes: H01J 2237/2814 Measurement of surface topography
• CPC Class Codes: H01J 2237/31749 Focused ion beam
• CPC Class Codes: H01J 37/28 with scanning beams H01J37/268, H01J37/292, H01J37/2955 take precedence
• CPC Class Codes: H01J 37/317 for changing properties of the objects or for applying thin layers thereon, e.g. for ion implantation H01J37/36 takes precedence

Abstract

The objective of the present invention is to provide a height measurement device capable of highly accurate measurement in the depth direction of a structure on a sample. To achieve this objective, proposed are a charged particle beam device and a height measurement device that is provided with a calculation device for determining the size of a structure on a sample on the basis of a detection signal obtained by irradiating the sample with a charged particle beam, wherein the calculation device calculates the distance from a first charged particle beam irradiation mark formed at a first height on the sample and a second charged particle beam irradiation mark formed at a second height on the sample and on the basis of this distance and the charged particle beam irradiation angle when the first charged particle beam irradiation mark and second charged particle beam irradiation mark were formed, calculates the distance between the first height and the second height.

Claims

1. A height measurement device comprising:

a calculation device that calculates a dimension of a structure on a sample based on a detection signal acquired by irradiating the sample with charged particle beams,

wherein the calculation device calculates a dimension between an irradiation mark of a first charged particle beam formed in a first height of the sample and an irradiation mark of a second charged particle beam formed is a second height of the sample, and calculates a dimension between the first height and the second height based on the dimension, irradiation angles using the charged particle beams when the irradiation marks of the first charged particle beam and the irradiation marks of the second charged particle beam are formed, or an angle of an inclined surface formed by cutting a part of the irradiation mark of the first charged particle beam and a part of the irradiation mark of the second charged particle beam.

2. The height measurement device according to claim 1,

wherein the irradiation mark of the first charged particle beam and the irradiation mark the second charged particle beam are formed by irradiating the sample with charged particle beams inclined at an angle of α

with respect to a vertical direction of the sample surface.

3. The height measurement device according to claim 2, wherein the calculation device calculates dimensions d of the first height and the second height based on a dimension s between the irradiation mark of the first charged particle beam and the irradiation mark of the second charged particle beam and d=s/tan(α

).

4. The height measurement device according to claim 1, wherein the calculation device calculates dimensions between first heights and second heights of a plurality of portions in the sample based on calculation of a plurality of dimensions between irradiation marks of a plurality of first charged particle beams and irradiation marks of a plurality of second charged particle beams which are formed in the sample.

5. The height measurement device according to claim 1, wherein the calculation device calculates the irradiation angles of the charged particle beams when the irradiation mark of the first charged particle beam and the irradiation mark of the second charged particle beam are formed based on the detection signal.

6. The height measurement device according to claim 5,

wherein the calculation device performs calculation using the following calculation expression based on the detection signal.

θ

=arcsin(D/B)

θ

=incident angle of charged particle beam

D=size of drawing pattern formed in sample

B=size of irradiation range using charged particle beam

7. The height measurement device according to claim 1, wherein the calculation device calculates dimensions d of the first height and the second height based on a dimension s between the irradiation mark of the first charged particle beam and the irradiation mark of the second charged particle beam, an angle γ

of the inclined surface, and d=s×

tan γ

.

8. A height measurement device comprising:

a calculation device which calculates a dimension of a structure on a sample based on a detection signal acquired by irradiating the sample with charged particle beams,

wherein the calculation device calculates a dimension s between a first portion on the sample and a second portion on the sample, and calculates a dimension between the first portion and the second portion based on the dimension s and the following expression.

d=s/tan(α

)

d;

height difference between first portion and second portion

α

;

relative angle between a vertical line of sample surface and a virtual straight line that connects first portion and second portion

9. A charged particle beam device comprising:

a detector which detects charged particles acquired by irradiating a sample provided in a sample chamber with charged particle beams emitted from a charged particle source, and a calculation device which measures a dimension of a structure formed on the sample based on an output of the detector,

wherein the calculation device calculates a dimension between an irradiation mark of a first charged particle beam formed in a first height of the sample and a an irradiation mark of a second charged particle beam formed in a second height of the sample, and calculates a dimension between the first height and the second height based on the dimension, irradiation angles using the charged particle beams when the irradiation mark of the first charged particle beam and the irradiation mark of the second charged particle beam are formed, or an angle of an inclined surface formed by cutting a part of the irradiation mark of the first charged particle beam and a part of the irradiation mark of the second charged particle beam.

10. The charged particle beam device according to claim 9, wherein ion beam columns that form the irradiation mark of the first charged particle beam and the irradiation mark of the second charged particle beam are provided in the sample chamber.

11. A height measurement method of measuring a dimension of a structure on a sample in a height direction, the method comprising:

forming an irradiation mark of a first charged particle beam and an irradiation mark of a second charged particle beam in a first height portion on the sample and a second height portion on the sample by irradiating the first height portion and the second height portion with the charged particle beams in a direction in which the charged particle beams are inclined at an angle of α

with respect to a vertical direction of the sample surface; and

scanning the sample with the charged particle beams in the vertical direction after the irradiation mark of the first charged particle beam and the irradiation mark of the second charged particle beam are formed, measuring a dimension s between the irradiation mark of the first charged particle beam and the irradiation mark of the second charged particle beam based on a detection signal acquired through the scanning, and calculating a dimension between the first height portion and the second height portion based on the dimension s, the angle α

, or an angle γ

of an inclined surface formed by cutting a part of the irradiation mark of the first charged particle beam and a part of the irradiation mark of the second charged particle beam.