Exposure apparatus, exposure method, and device manufacturing method
First Claim
1. An exposure apparatus that irradiates an energy beam on a mask and transfers a pattern formed on said mask onto a substrate, said exposure apparatus comprising:
- a detection unit that detects the thickness of a light transmitting protective member protecting a pattern surface of said mask on which said pattern is formed.
1 Assignment
0 Petitions
Accused Products
Abstract
In an exposure apparatus, a main controller calculates the thickness of a light transmitting protective member that protects a pattern surface of a mask, based on detection signals of a first and second reflection beams of a detection beam irradiated from an irradiation system, reflected off the front and back surfaces of the protective member, and received by a photodetection system. This makes exposure that takes into account the variation in the image forming state of the image pattern depending on the calculated thickness of the protective member possible. Accordingly, exposure with high precision is possible, without the difference in thickness of the protective member protecting the pattern surface of the mask affecting the exposure. In addition, when the incident angle of the detection beam is optimized, setting a detection offset in the photodetection system, or resetting the origin will not be necessary.
24 Citations
41 Claims
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1. An exposure apparatus that irradiates an energy beam on a mask and transfers a pattern formed on said mask onto a substrate, said exposure apparatus comprising:
a detection unit that detects the thickness of a light transmitting protective member protecting a pattern surface of said mask on which said pattern is formed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 35, 36, 37, 38, 39)
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11. An exposure apparatus that irradiates an energy beam on a mask and transfers a pattern formed on said mask onto a substrate, said exposure apparatus comprising:
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a position detection system that has an irradiation system that irradiates a detection beam on a pattern surface of said mask on which said pattern is formed at an incident angle α
via a light transmitting transparent plate, which has a predetermined thickness and protects said pattern surface,a photodetection unit that receives a reflection beam reflected off said pattern surface and outputs its detection signal, and a calculation unit that calculates a position of said pattern surface in a normal direction of said pattern surface, based on an output of said photodetection unit; and
a projection optical system which optical axis is in said normal direction and projects said energy beam outgoing from said mask onto said substrate, whereby when an outgoing angle of said detection beam entering said transparent plate is expressed as β
, a maximum angle of an incident angle of said energy beam to said transparent plate is expressed as α
′
, said maximum angle of said incident angle of said energy beam being set by a numeric aperture and a projection magnification of said projection optical system, and an outgoing angle of said energy beam entering said transparent plate is expressed as β
′
, said incident angle α
is set to satisfy a relation expressed as;
tan β
/tan α
=tan β
′
/tan α
′
. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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18. An exposure apparatus that irradiates an energy beam on a mask and transfers a pattern formed on said mask onto a substrate, said exposure apparatus comprising:
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an irradiation system that irradiates a detection beam on a pattern surface of said mask on which said pattern is formed from a direction of a predetermined angle of inclination via a light transmitting transparent plate, which has a predetermined thickness and protects said pattern surface;
a position detection unit that receives a reflection beam reflected off said pattern surface, and detects a position of said pattern surface in a normal direction, and a calibration unit that calibrates said position detection unit, based on the thickness of said transparent plate. - View Dependent Claims (19, 20, 40, 41)
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21. An exposure method in which an energy beam exposes a substrate via a mask on which a pattern is formed to transfer an image of said pattern on said substrate, said exposure method including:
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a detection process in which the thickness of a light transmitting protective member protecting a pattern surface of said mask where said pattern is formed is detected; and
a correction process in which an image forming state of said pattern is corrected, based on said thickness of said light transmitting protective member detected in said detection process. - View Dependent Claims (22, 23, 24, 25)
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26. An exposure method in which an energy beam is irradiated on a mask, and a pattern formed on said mask is transferred onto a substrate via a projection optical system, said exposure method including:
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a process of irradiating a detection beam on a pattern surface of said mask on which said pattern is formed at an incident angle α
via a light transmitting transparent plate, which has a predetermined thickness and protects said pattern surface; and
a process of calculating a position of said pattern surface in an optical axis direction of said projection optical system, which is a normal direction of said pattern surface, when a reflection beam reflected off said pattern surface is received, based on its results, whereby when an outgoing angle of said detection beam entering said transparent plate is expressed as β
, a maximum angle of an incident angle of said energy beam to said transparent plate is expressed as α
′
, said maximum angle of said incident angle of said energy beam being set by a numeric aperture and a projection magnification of said projection optical system, and an outgoing angle of said energy beam entering said transparent plate is expressed as β
′
, said incident angle α
is set to satisfy a relation expressed as;
tan β
/tan α
=tan β
′
/tan α
′
. - View Dependent Claims (27)
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28. An exposure method in which an energy beam having a wavelength of 157 nm is irradiated on a mask, and a pattern formed on said mask is transferred onto a substrate via a projection optical system, said exposure method including:
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a process of irradiating a detection beam on a pattern surface of said mask on which said pattern is formed in an incident angle range of 30°
to 50°
; and
a process of calculating a position of said pattern surface in an optical axis direction of said projection optical system when a reflection beam of said detection beam reflected off said pattern surface is received, based on its results. - View Dependent Claims (29, 30)
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31. An exposure method in which an energy beam is irradiated on a mask, and a pattern formed on said mask is transferred onto a substrate, said exposure method including:
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an irradiation process in which a detection beam is irradiated on a pattern surface of said mask on which said pattern is formed from a direction of a predetermined angle of inclination via a light transmitting transparent plate, which has a predetermined thickness and protects said pattern surface; and
a position detection/correction process in which a position of said pattern surface in a normal direction is detected when a reflection beam reflected off said pattern surface is received and said position of said pattern surface in said normal direction is corrected, based on the thickness of said transparent plate. - View Dependent Claims (32, 33, 34)
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Specification