Automatic focusing system for scanning electron microscope equipped with laser defect detection function
First Claim
1. An automatic focusing method used by a scanning electron microscope equipped with a laser defect detection function, the method comprising:
- obtaining an accurate offset amount between focal positions of an optical microscope and a scanning electron microscope;
detecting a defect by a laser dark-field image provided by the optical microscope;
analyzing the dark-field image to readjust a focus of the optical microscope;
automatically adjusting a focus of the scanning electron microscope by adding a readjusted amount of the focus of the optical microscope to the offset amount before an observation is conducted by the scanning electron microscope.
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Accused Products
Abstract
A scanning electron microscope equipped with a laser defect detection function has an automatic focusing function that performs the steps of: obtaining a deviation (offset) amount between focal positions of an optical microscope and a scanning electron microscope; detecting a defect by a laser dark-field image of the optical microscope; analyzing the dark-field image to readjust a focus of the optical microscope to adjust a height of the optical microscope; and automatically adjusting a focus of the scanning electron microscope by adding a readjusted amount of the focus of the optical microscope to the offset amount before an observation is conducted by the scanning electron microscope.
15 Citations
20 Claims
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1. An automatic focusing method used by a scanning electron microscope equipped with a laser defect detection function, the method comprising:
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obtaining an accurate offset amount between focal positions of an optical microscope and a scanning electron microscope;
detecting a defect by a laser dark-field image provided by the optical microscope;
analyzing the dark-field image to readjust a focus of the optical microscope;
automatically adjusting a focus of the scanning electron microscope by adding a readjusted amount of the focus of the optical microscope to the offset amount before an observation is conducted by the scanning electron microscope. - View Dependent Claims (2)
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3. A particle defect examination apparatus comprising a scanning electron microscope equipped with a laser defect detection function by use of an optical microscope, the particle defect examination apparatus comprising:
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a storage device that stores an accurate offset amount between focal positions of the optical microscope and the scanning electron microscope;
an analysis device that performs an analysis to find a focused position of the optical microscope based on a laser dark-field image obtained by the optical microscope; and
a device that automatically adjusts a focus of the scanning electron microscope by adding a readjusted amount of the focus of the optical microscope to the offset amount. - View Dependent Claims (4, 5, 6, 7, 8, 9)
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10. A particle defect examination apparatus comprising:
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an optical microscope that photographs an image of at least one defect;
a scanning electron microscope;
a storage device that stores an accurate offset amount between focal positions of the optical microscope and the scanning electron microscope;
an analysis device that analyzes the image to readjust a focused position of the optical microscope; and
a device that automatically adjust a focus of the scanning electron microscope by adding a readjusted amount of the focused position of the optical microscope to the offset amount. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification