Alignment device having irradiation and detection light correcting optical elements

An alignment device adapted for use in an exposure apparatus equipped with a projection optical system for transferring a predetermined pattern, formed on a reticle, onto a substrate with an exposure light, and adapted for setting the position of said substrate by detecting the position of a diffraction grating mark formed on said substrate, comprising:

• light irradiation means for irradiating said diffraction grating mark, through said projection optical system, from predetermined two directions, with two alignment light beams having a predetermined frequency difference and also having a wavelength different from that of said exposure light;
• detection means for detecting, through said projection optical system, a predetermined diffracted light beam from said diffraction grating mark;
• movement means for moving said substrate, based on a detection signal from said detection means;
• an irradiation light correcting optical element provided in said projection optical system and adapted for deflecting the irradiation optical paths so as to correct, by predetermined amounts, the longitudinal chromatic aberration and the chromatic aberration of magnification of said projection optical system for said irradiation light beams;
• and
• a detection light correcting optical element provided in said projection optical system and adapted for deflecting the detection optical path toward the peripheral part of the exposure area of said reticle, so as to correct, by a predetermined amount, the chromatic aberration of magnification of said projection optical system for said detection light beam;
• wherein said irradiation light correcting optical element and said detection light correcting optical element are provided in a plane perpendicular to the optical axis of said projection optical system.

An alignment device adapted for use in an exposure apparatus equipped with a projection optical system for transferring a predetermined pattern, formed on a reticle, onto a substrate with an exposure light, and adapted for detecting the position of a diffraction grating mark formed on said substrate, comprising:

• light irradiation means for irradiating said diffraction grating mark, through said projection optical system, with alignment light of a wavelength different from that of said exposure light;
• detection means for detecting, through said projection optical system, diffracted light from said diffraction grating mark;
• an irradiation light correcting optical element provided between said reticle and said substrate and adapted for deflecting the irradiation optical path so as to correct, by a predetermined amount, the chromatic aberration of magnification of the projection optical system for the irradiation light;
• and
• a detection light correcting optical element provided between said reticle and said substrate and adapted for deflecting the detection optical path toward the peripheral part of an exposure area of said reticle, so as to correct, by predetermined amounts, the longitudinal chromatic aberration and the chromatic aberration of magnification of the projection optical system for said detection light.

An alignment device adapted for use in an exposure apparatus equipped with a projection optical system for transferring a predetermined pattern, formed on a reticle, onto a substrate with an exposure light, and adapted for detecting the position of an alignment mark formed on said substrate, comprising:

• light irradiation means for irradiating said alignment mark, through said projection optical system, with alignment light of a wavelength different from that of said exposure light;
• detection means for detecting, through said projection optical system, light from said alignment mark;
• an irradiation light correcting optical element for generating a longitudinal chromatic aberration and a chromatic aberration of magnification which are opposite, in direction, to the longitudinal chromatic aberration and the chromatic aberration of magnification of said projection optical system for the irradiation light, and a detection light correcting optical element for generating a chromatic aberration of magnification which is opposite, in direction, to the chromatic aberration of magnification of said projection optical system for the detection light, both elements being positioned between said reticle and said substrate;
• wherein said irradiation light correcting optical element is adapted to generate a longitudinal chromatic aberration equal to that of said projection optical system at a first position at which an image of said alignment mark is projected by said projection optical system onto said reticle under said irradiation light, and also to generate a chromatic aberration of magnification not less than that of said projection optical system at said first position, thereby deflecting the irradiation optical path toward the peripheral part of a non-exposure area of which boundary includes a second position where an image of said alignment mark is projected by said projection optical system onto said reticle under said exposure light;
• and
• said detection light correcting optical element is adapted to generate a chromatic aberration of magnification exceeding that of said projection optical system at said first position, thereby deflecting the detection optical path toward the peripheral part of the non-exposure are of which boundary contains said second position.

An alignment device adapted for use in an exposure apparatus equipped with a projection optical system for transferring a predetermined pattern, formed on a reticle, onto a substrate with an exposure light, and adapted for detecting the position of an alignment mark formed on said substrate, comprising:

• light irradiation means for irradiating said alignment mark, through said projection optical system, with alignment light of a wavelength different from that of said exposure light;
• detection means for detecting, through said projection optical system, light from said alignment mark;
• an irradiation light correcting optical element for generating a chromatic aberration which is opposite, in direction, to that of said projection optical system for the irradiation light, and a detection light correcting optical element for generating a longitudinal chromatic aberration and a chromatic aberration of magnification which are opposite, in direction, to those of said projection optical system for the detection light, both elements being positioned between said reticle and said substrate;
• wherein said irradiation light correcting optical element is adapted to generate a chromatic aberration of magnification exceeding that of said projection optical system at a first position at which an image of said alignment mark is projected by said projection optical system onto said reticle under said irradiation light, thereby deflecting the irradiation optical path toward the peripheral part of a non-exposure area of which boundary includes a second position where an image of said alignment mark is projected by said projection optical system onto said reticle under said exposure light;
• and
• said detection light correcting optical element is adapted to generate a longitudinal chromatic aberration equal to that of said projection optical system at said first position and also to generate a chromatic aberration of magnification exceeding that of said projection optical system at said first position, thereby deflecting the detection optical path toward the peripheral part of the non-exposure area of which boundary contains said second position.