Wavelength selecting method, position detecting method and apparatus, exposure method and apparatus, and device manufacturing method
AssigneeCanon Kabushiki Kaisha
InventorTakahiro Matsumoto
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Abstract
A wavelength selecting method for selecting a wavelength of light, the light being used to detect a position of a target with a signal from an image of an alignment mark covered with resist, includes the steps of obtaining a reflectance of the resist at a position outside the alignment mark by irradiating lights having plural wavelengths to the resist at the position, and selecting one of the lights which one has a wavelength that provides the maximum value of reflectance among the reflectances measured by the measuring step or which one has a wavelength that falls within a predetermined wave range centering on the wavelength that provide the maximum reflectance.
Claims4
A wavelength selecting method for selecting a wavelength of light used to detect a position of a target, said wavelength selecting method comprising the steps of:
- projecting an image of a pattern that includes plural elements using plural lights having different wavelengths onto measuring positions on plural areas of the target, and detecting a signal waveform from the plural areas of the target;
- obtaining plural element intervals for each of the plural wavelengths based on the signal waveform detected by said detecting step;
- calculating a standard deviation of the plural element intervals at the measuring positions in the plural areas based on the plural element intervals;
- and
- selecting one of the wavelengths that provides a smallest standard deviation among the plural standard deviations calculated by said calculating step.
A wavelength selecting method for selecting a wavelength of light used to detect a position of a target, said wavelength selecting method comprising the steps of:
- projecting an image of a pattern that includes plural elements using plural lights having different wavelengths onto measuring positions on plural areas of the target, and obtaining positional information indicative of the position;
- obtaining an approximate curved surface from an average of the wavelengths of the positional information obtained in said obtaining step;
- calculating an offset amount of the positional information from the approximate curved surface;
- and
- selecting one of the wavelengths which one minimizes scattering among the plural areas based on the offset amounts calculated by said calculating step.
Dependencies are inferred from the claim text.