Charged particle beam apparatus and navigation image correction method

Abstract

A charged particle beam apparatus 100 comprises a charged particle beam optical system 102, an optical camera 117, a stage 104, a CPU 124, a display unit 123, and an image correction unit 118. The CPU 124 rotates the stage 104 and makes the optical camera 117 photograph a sample stand 103 mounted on the stage 104. On the basis of a result of photographing the sample stand 103 mounted on the stage 104 that has been rotated, the image correction unit 118 determines the rotational center position of the sample stand 103, and corrects the position of a navigation image displayed on the display unit 123 by using the rotational center position.

Claims

1. A charged particle beam apparatus comprising: a charged particle beam optical system for irradiating a sample mounted on a sample stage with a charged particle beam; an optical camera for photographing the sample stage; a stage on which the sample stage is mounted and which is rotatable in a plane including at least a first direction and a second direction intersecting the first direction; a controller for controlling the shooting operation of the optical camera; a stage controller for controlling the rotational operation of the stage based on instructions from the controller; a display unit for displaying the optical image acquired by the optical camera as a navigation image; and an image correction unit for correcting the rotation center position of the navigation image when the stage is rotated, wherein the controller rotates the stage to cause the optical camera to photograph the sample stage; and the image correction unit determines the rotation center position of the sample stage based on the shooting result of the sample stage mounted on the rotated stage, and uses the determined rotation center position to correct the position of the navigation image displayed on the display unit.

2. A charged particle beam apparatus according to claim 1, wherein the controller further moves the stage in at least one of the first and second directions to cause the optical camera to photograph the sample stage, and the image correction unit further corrects the position of the navigation image in the first and second directions, determines the position of the sample stage when it has moved in at least one of the first and second directions based on the photographic result of the sample stage mounted on the stage which has moved in at least one of the first or second directions, and uses the determined position to correct the position of the navigation image displayed on the display unit.

3. A charged particle beam apparatus according to claim 1, wherein a plurality of feature points are provided on the sample stage, and the image correction unit corrects the position of the navigation image using the plurality of feature points included in the imaging result.

4. A charged particle beam apparatus according to claim 3, wherein the image correction unit corrects the position of the navigation image by having the stage rotate at different rotation angles, and using the intersection of the perpendicular bisectors of first feature points and second feature points, respectively, included in the optical image of the stage captured at each rotation angle as the rotation center position.

5. A charged particle beam apparatus according to claim 3, wherein the plurality of feature points include a first feature point and a second feature point located at a position different from the first feature point, the first feature point being a first mark, and the second feature point being a second mark.

6. A charged particle beam apparatus according to claim 1, wherein the navigation image is a second optical image different from the first optical image used for correction by the image correction unit.

7. A charged particle beam apparatus according to claim 6, wherein the second optical image is an optical image newly captured by the optical camera after correction by the image correction unit has been completed.

8. A charged particle beam apparatus according to claim 7, wherein the second optical image is an optical image in which at least one of the brightness, lightness and saturation is different from the first optical image.

9. A charged particle beam apparatus according to claim 1, wherein the display unit displays an execution button, and upon input of the execution button, the image correction unit performs a process to correct the position of the navigation image displayed on the display unit.

10. A charged particle beam apparatus according to claim 3, wherein the display unit displays an image selection button, and the optical image of the stage captured at the different rotation angles selected by the image selection button is displayed on the display unit.

11. A charged particle beam apparatus according to claim 1, further comprising a detection unit for detecting secondary electrons generated from a sample based on irradiation with the charged particle beam, wherein the display unit comprises: a stage observation position display unit for displaying the navigation image; and a detection image display unit for displaying an image based on the secondary electrons detected by the detection unit, wherein the stage observation position display unit displays an indicator indicating a position on the stage; and the detection image display unit displays an image of the sample at the position indicated by the indicator.

12. A navigation image correction method for a charged particle beam apparatus, the charged particle beam apparatus comprising: a charged particle beam optical system for irradiating a sample mounted on a sample stage with a charged particle beam; an optical camera for photographing the sample stage; a stage on which the sample stage is mounted and which is rotatable in a plane including at least a first direction and a second direction intersecting the first direction; a controller for controlling the shooting operation of the optical camera; a stage controller for controlling the rotation operation of the stage based on instructions from the controller; a display unit for displaying the optical image acquired by the optical camera as a navigation image; and an image correction unit for correcting the rotation center position of the navigation image when the stage is rotated, when the navigation image is displayed on the display unit, the navigation image correction method comprising: a step of the controller rotating the stage to cause the optical camera to photograph the sample stage; and a step of the image correction unit determining the rotation center position of the sample stage based on the shooting result of the sample stage mounted on the rotated stage, and correcting the position of the navigation image displayed on the display unit using the determined rotation center position. A navigation image correction method having the following characteristics.

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