Optical microscope device and testing apparatus comprising same
AssigneeHitachi High-Technologies Corporation
InventorsKei Shimura, Tetsuya Niibori, Mizuki Oku, Naoya Nakai
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Abstract
The present invention allows observation or capturing of a high-contrast image of a sample for which sufficient contrast cannot be obtained in bright-field observation, such as a wafer having a pattern with a small pattern height. According to the present invention, a sample is illuminated through an objective lens used for capturing an image, and an imaging optics are provided with an aperture filter so that an image is captured while light of bright-field observation components is significantly attenuated.
Claims7
An optical microscope device for observing or capturing a magnified image of a sample, the device comprising:
- an illumination light source;
- an illumination optics adapted to guide a light beam from the illumination light source to the sample;
- an imaging optics adapted to collect a light beam from the sample and form an image of the sample;
- a first aperture filter arranged on a system stop plane of the imaging optics, the first aperture filter being adapted to attenuate a specular reflection component;
- an image sensor arranged on an image plane of the imaging optics, the image sensor being adapted to convert an optical image into an electric signal;
- and a second aperture filter arranged in the illumination optics on a plane that is conjugate to the plane on which the first aperture filter is arranged;
- wherein one of the first or second aperture filter has a circular aperture with a coherence factor that is less than 1 (a<1), and the other has an annular aperture.
Dependencies are inferred from the claim text.