Method of measuring mark position and measuring apparatus
AssigneeCanon Kabushiki Kaisha
InventorSatoru Oishi
Life of this patent
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Abstract
A method and an apparatus are provided to measure a position of a mark with a less measurement error caused by a variation in a wafer process condition. The mark is illuminated with light and an image of the mark is formed, via an optical system, in a light receiving surface of a sensor. The image of the mark is sensed and image data thereof is acquired by the sensor. Correction data of a fundamental harmonic and a high harmonic of the image data is set based on information associated with a shape of the mark, an imaging magnification of the optical system, and an area of the sensor. The image data is corrected using the correction data, and the position of the mark is calculated using the corrected image data.
Claims16
A method comprising:
- acquiring data of an image of a mark formed on a substrate by an optical system and sensed by a sensor;
- setting correction data of a fundamental harmonic and a high harmonic of the data based on information associated with a shape of the mark, an imaging magnification of the optical system, and an area of the sensor;
- correcting the data based on the correction data;
- and
- calculating a position of the mark based on the corrected data.
A measurement apparatus comprising:
- an optical system configured to form an image of a mark in a plane;
- a sensor configured to sense the formed image and output data of the sensed image;
- a calculation unit configured to calculate a position of the mark;
- and
- a storage unit configured to store correction data of a fundamental harmonic and a high harmonic of the data, the correction data being determined using information associated with a shape of the mark, an imaging magnification of the optical system, and an area of the sensor,
- wherein the calculation unit corrects the data using the correction data and calculates the position of the mark using the corrected data.
A storage medium including a program stored therein for making a computer calculate a position of a mark formed on a substrate, the program comprising:
- correcting data obtained by taking an image of the mark using an optical system and a sensor, based on correction data of a fundamental harmonic and a high harmonic of the data defined based on information associated with a shape of the mark, an imaging magnification of the optical system, and an area of the sensor;
- and
- calculating the position of the mark using the corrected data.
A measurement method comprising:
- forming an image of a mark in a plane by an optical system;
- sensing the formed image and outputting data of the sensed image by a sensor;
- calculating a position of the mark;
- determining correction data of a fundamental harmonic and a high harmonic of the data using information associated with a shape of the mark, an imaging magnification of the optical system, and an area of the sensor;
- and
- storing the correction data;
- correcting the data using the correction data;
- and
- calculating the position of the mark using the corrected data.
An apparatus comprising:
- an acquiring unit configured to acquire data of an image of a mark formed on a substrate by an optical system and sensed by a sensor;
- a setting unit configure to set correction data of a fundamental harmonic and a high harmonic of the data based on information associated with a shape of the mark, an imaging magnification of the optical system, and an area of the sensor;
- a correcting unit configured to correct the data based on the correction data;
- and
- a calculating unit configured to calculate a position of the mark based on the corrected data.
A computer readable storage medium storing a computer-executable program of instructions for causing a computer to perform a method comprising:
- forming an image of a mark in a plane by an optical system;
- sensing the formed image and outputting data of the sensed image by a sensor;
- calculating a position of the mark;
- determining correction data of a fundamental harmonic and a high harmonic of the data using information associated with a shape of the mark, an imaging magnification of the optical system, and an area of the sensor;
- and
- storing the correction data;
- correcting the data using the correction data;
- and
- calculating the position of the mark using the corrected data.
Dependencies are inferred from the claim text.