Fine structure evaluation apparatus and method
AssigneeCanon Kabushiki Kaisha
InventorsToshihiko Tsuji, Kenji Saito
Life of this patent
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Abstract
In an apparatus and a method for evaluating the pattern structure of a fine structure, the presence of foreign particles, or the like, an object having a fine structure is scanned with a light beam, or the spot size of the light beam projected onto the object is changed, and extreme values in light scattered by the object are detected. The fine structure is evaluated according to changes in the positions, the number, the intensities or the like of the extreme values, that is, according to distribution characteristics of the extreme values caused by the scanning or the changes in the spot size of the light beam.
Claims21
An apparatus for evaluating a fine structure of an object to be inspected, said apparatus comprising:
- illumination means for irradiating the object with a light beam;
- irradiating state changing means for changing an irradiating state of the light beam irradiating the object by said illumination means;
- detection means for detecting those portions having extreme intensity values of light scattered by the illuminated object, and for producing a detection output;
- and
- calculation means for receiving the detection output from said detection means, and for evaluating the fine structure of the object according to changes in distribution characteristics of those portions having the extreme intensity values while changing the irradiating state of the light beam by said irradiating state changing means.
A method of evaluating a fine structure of an object to be inspected, said method comprising the steps of:
- irradiating a light beam onto the object;
- changing an irradiating state of the light beam;
- detecting those portions of light scattered by the irradiated object having extreme intensity values;
- and
- evaluating the fine structure of the object according to changes in distribution characteristics of those detected portions having the extreme values, while changing the irradiating state of the light beam.
An apparatus for evaluating a fine structure of an object to be inspected, said apparatus comprising:
- a light source for emitting a light beam;
- an illuminating optical system for receiving the light beam emitted from said light source and for irradiating a light beam a predetermined position of the object, said illuminating optical system being capable of changing an irradiating state of the light beam onto the object;
- a photoelectric transducer for detecting those portions of light scattered by the irradiated object having extreme intensity values;
- and
- a signal processing system for evaluating the fine structure of the object according to changes in distribution characteristics of those detected portions having the extreme values, while changing the irradiating state of the light beam by said illuminating optical system.
Dependencies are inferred from the claim text.