CHARGED PARTICLE BEAM APPARATUS

• US 20110260057A1
• Filed: 10/22/2009
• Published: 10/27/2011
• Est. Priority Date: 10/24/2008
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Yano, Manabu, Kawano, Hajime, Ito, Hiroyuki, Ishii, Ryoichi, Otaka, Tadashi
• Granted Patent: US 8,334,520 B2
• Time in Patent Office: Days
• US Class Current: 250/307
• CPC Class Codes: H01J 2237/20214 Rotation
• CPC Class Codes: H01J 2237/2811 Large objects
• CPC Class Codes: H01J 2237/2817 Pattern inspection
• CPC Class Codes: H01J 37/20 Means for supporting or positioning the objects or the material; Means for adjusting diaphragms or lenses associated with the support introducing the objects H01J37/18
• CPC Class Codes: H01J 37/28 with scanning beams H01J37/268, H01J37/292, H01J37/2955 take precedence

Abstract

According to a charged particle beam apparatus of this invention, an inspection position on a test sample (wafer coordinate system) is converted to a setting position of an inspection mechanism (stage coordinate system (polar coordinate system)), a rotating arm (102,1012) and a rotating stage (103,1011) being rotated to be moved for the inspection position on the test sample.

In this case, a plurality of inspection devices are arranged over a locus that is drawn by the center of the rotating stage according to the rotation of the rotating arm. A function for calculating errors (e.g., center shift of the rotating stage) and compensating for the errors is provided, by which the precision of inspection is improved in a charged particle beam apparatus equipped with a biaxial rotating stage mechanism. With this configuration, a charged particle beam apparatus which is small-sized and capable of easy stage control can be realized.

Claims

1. A charged particle beam apparatus for conducting inspection or measurement of a target sample using a secondary particle image, the apparatus comprising:

a biaxial rotating stage mechanism including a rotating stage (103, 1010) which rotates the target sample placed thereon around a prescribed rotation center, a rotating arm (102, 1012) which supports the rotating stage and moves the rotating stage along an ark-shaped path, means (1101) for driving and rotating the rotating stage, and means (1014) for driving the rotating arm; and

a plurality of inspection mechanisms including a charged particle optical lens tube (1001, 1002) for acquiring the secondary particle image by irradiating the target sample with a primary charged particle beam,

wherein the plurality of inspection mechanisms are arranged over a locus that is drawn by the rotation center of the rotating stage according to the rotation of the rotating arm.

2. The charged particle beam apparatus according to claim 1,

wherein a minimum movable range of the rotating arm is set so that maximum distance between rotation centers of the rotating stage within the rotating arm'"'"'s movable range is greater than the radius of the sample.

3. The charged particle beam apparatus according to claim 2,

wherein the minimum movable range of the rotating arm is set to further expand by a permissible misalignment caused by a setting position error of the inspection mechanism or a rotational error of the rotating arm.

4. The charged particle beam apparatus according to claim 1, further comprising:

a stage control unit (1102) which controls the operation of the rotating stage and the rotating arm by transforming orthogonal coordinate values of an image acquiring position on the sample into polar coordinate values.

5. The charged particle beam apparatus according to claim 1,

wherein the plurality of inspection mechanisms include an optical microscope in addition to the charged particle optical lens tube.

6. The charged particle beam apparatus according to claim 5,

wherein the plurality of inspection mechanisms include a surface electric field measurement instrument (904) or a charge remover (905).

7. The charged particle beam apparatus according to claim 1,

wherein a turning radius R₁ of the rotating arm is substantially equal to a turning radius R₂ of the rotating stage;

and

wherein edge/bevel inspection means (906) is arranged substantially over a circumference along the locus of the movement of the rotating arm.

8. The charged particle beam apparatus according to claim 1, further comprising:

means (104, 1106) for compensating for eccentricity of the rotating stage.

9. The charged particle beam apparatus according to claim 8, further comprising:

a stage control unit (1102) which calculates a correction value for the eccentricity compensation by calculating deviation of the real rotation center of the rotating stage from an ideal rotation center based on information on a locus drawn by the rotation center of the rotating stage according to the rotation of the rotating stage.

10. The charged particle beam apparatus according to claim 1, further comprising

control means (1106) which sets paths connecting acquiring positions of the secondary particle images on the sample as concentric circular paths.

11. The charged particle beam apparatus according to claim 10,

wherein the apparatus acquires an image by an image shift when the path set by the control means enters a dead zone of the apparatus.

12. A charged particle beam apparatus for conducting inspection or measurement of a target sample using a secondary particle image, the apparatus comprising:

a biaxial rotating stage mechanism including a rotating stage (103, 1010) which rotates the target sample placed thereon around a prescribed rotation center, a rotating arm (102, 1012) which supports the rotating stage and moves the rotating stage along an ark-shaped path, means (1101) for driving and rotating the rotating stage, and means (1014) for driving the rotating arm; and

a plurality of inspection mechanisms including a charged particle optical lens tube (1001, 1002) for acquiring the secondary particle image by irradiating the target sample with a primary charged particle beam,

wherein the biaxial rotating stage mechanism includes;

a support shaft (1012-a) which is provided at an end of the rotating arm opposite to the rotating stage supporting position and serves as a rotation center of the rotating arm;

a guide mechanism (1013) which supports a basal part of the other end of the rotating arm opposite to the center shaft; and

a driver (1014) which moves the rotating arm along the guide mechanism.

13. The charged particle beam apparatus according to claim 12,

wherein the driver is a non-backlash motor.

14. The charged particle beam apparatus according to claim 13, further comprising:

a rotation angle detector (1016) which detects a rotation angle of the rotating arm.

15. The charged particle beam apparatus according to claim 14,

wherein wires for the rotating arm driver and the rotation angle detector are laid along the rotating arm;

and

wherein a wire-extracting part (1017, 1018) is formed in the vicinity of the support shaft of the rotating arm.

16. The charged particle beam apparatus according to claim 12, further comprising:

a temperature sensor (1019) which measures temperature of the rotating arm; and

calculation means (1102) which calculates a turning radius of the rotating arm from temperature data obtained by the temperature sensor, and calculates a rotation control value for the rotating arm or the rotating stage from the calculated turning radius.

17. The charged particle beam apparatus according to claim 12, further comprising:

a temperature sensor (1019) which measures temperature of the rotating arm;

temperature adjustment means which adjusts the temperature of the rotating arm; and

calculation means which controls operation of the temperature adjustment means using temperature data obtained by the temperature sensor.

18. The charged particle beam apparatus according to claim 12, further comprising:

a drive motor employing a piezoelectric element or an ultrasonic motor as driving means for the rotating stage or the rotating arm.

19. A method for acquiring a charged particle image using a charged particle beam apparatus, the apparatus comprising:

a biaxial rotating stage mechanism including a rotating stage (103, 1010) which rotates a target sample placed thereon around a prescribed rotation center, a rotating arm (102, 1012) which supports the rotating stage and moves the rotating stage along an ark-shaped path, means (1101) for driving and rotating the rotating stage, and means (1014) for driving the rotating arm; and

a plurality of inspection mechanisms including a charged particle optical lens tube (1001, 1002) for acquiring a secondary particle image by irradiating the target sample with a primary charged particle beam,

wherein the rotating arm is rotated by moving an end of the rotating arm opposite to the rotating stage supporting position when an image acquiring position on the sample is moved to a position right under the inspection mechanism.