Projection exposure methods using difracted light with increased intensity portions spaced from the optical axis

A method of exposing an object through a projection optical system with light irradiated on a mask from a light source through an illumination optical system, comprising:

• disposing a diffraction optical element that generates diffracted light in different directions from an optical axis of the illumination optical system between the light source and an optical integrator in the illumination optical system;
• distributing the diffracted light at regions apart from the optical axis on a predetermined plane substantially conjugate with a pupil plane of the projection optical system in the illumination optical system to form on the predetermined plane an intensity distribution having increased intensity portions apart from the optical axis relative to a portion of the intensity distribution on the optical axis, two diffracted light having different order generated from a pattern by irradiation of light from each one of the increased intensity portions being distributed at different regions, of which distances from an optical axis of said projection optical system are substantially equal, on the pupil plane of the projection optical system, the two diffracted light including 0-order diffracted light and non-0-order diffracted light that satisfies the following relation in the resolution limit of the projection optical system:
• sin(θ−Φ)=NAR
• where Φ is an incident angle of light from each one of the increased intensity portions, θ is an angle of diffraction of the non-0-order diffracted light, and NAR is a numerical aperture of the projection optical system;
• and
• projecting onto the object through the projection optical system the illuminated pattern with light of which the intensity distribution has the increased intensity portions on the predetermined plane in the illumination optical system.

A method of exposing an object through a projection optical system with light irradiated on a mask from a light source through an illumination optical system, comprising:

• disposing a diffraction optical element that generates diffracted light in different directions from an optical axis of the illumination optical system between the light source and an optical integrator in the illumination optical system;
• distributing the diffracted light at regions apart from the optical axis on a predetermined plane substantially conjugate with a pupil plane of the projection optical system in the illumination optical system to form on the predetermined plane an intensity distribution having increased intensity portions apart from the optical axis relative to a portion of the intensity distribution on the optical axis, first diffracted light generated from a pattern by irradiation of light from a first one of the increased intensity portions being distributed at a region, on an pupil plane of the projection optical system, at which at least part of second diffracted light having different order from the first diffracted light, generated from the pattern by irradiation of light from a second one of the increased intensity portions different from the first increased intensity portion is distributed;
• and
• projecting onto the object through the projection optical system the illuminated pattern with light of which the intensity distribution has the increased intensity portions on the predetermined plane in the illumination optical system.

A method of exposing an object through a projection optical system with light irradiated on a mask from a light source through an illumination optical system, comprising:

• disposing a diffraction optical element that generates diffracted light in different directions from an optical axis of the illumination optical system between the light source and an optical integrator in the illumination optical system;
• distributing the diffracted light at regions apart from the optical axis on a predetermined plane substantially conjugate with a pupil plane of the projection optical system in the illumination optical system to form on the predetermined plane an intensity distribution having increased intensity portions apart from the optical axis relative to a portion of the intensity distribution on the optical axis, an incident angle of light from each one of the increased intensity portions satisfying the following relation:
• sin Φ=λ/2P
• where Φ is the incident angle, λ is a wavelength of the light, and P is a pitch of a pattern on the mask;
• and
• projecting onto the object through the projection optical system the illuminated pattern with light of which the intensity distribution has the increased intensity portions on the predetermined plane in the illumination optical system.

A method of exposing an object through a projection optical system with light irradiated on a mask from a light source through an illumination optical system, comprising:

• disposing a diffraction optical element that generates diffracted light in different directions from an optical axis of the illumination optical system between the light source and an optical integrator in the illumination optical system;
• distributing the diffracted light at regions apart from the optical axis on a predetermined plane substantially conjugate with a pupil plane of the projection optical system in the illumination optical system to form on the predetermined plane an intensity distribution having increased intensity portions apart from the optical axis relative to a portion of the intensity distribution on the optical axis, three diffracted light generated from a pattern by irradiation of light from each one of the increased intensity portions being distributed at substantially equal distances from an optical axis of the projection optical system on the pupil plane of the projection optical system, the three diffracted light including 0-order diffracted light, non-0-order diffracted light distributed in a first direction about the 0-order diffracted light and non-0-order diffracted light distributed in a second direction about the 0-order diffracted light;
• and
• projecting onto the object through the projection optical system the illuminated pattern with light of which the intensity distribution has the increased intensity portions on the predetermined plane in the illumination optical system.

A method of exposing an object through a projection optical system with light irradiated on a mask from a light source through an illumination optical system, comprising:

• disposing a diffraction optical element that generates diffracted light in different directions from an optical axis of the illumination optical system between the light source and an optical integrator in the illumination optical system;
• distributing the diffracted light at regions apart from the optical axis on a predetermined plane substantially conjugate with a pupil plane of the projection optical system in the illumination optical system to form on the predetermined plane an intensity distribution having increased intensity portions substantially disposed on a first pair of line segments relative to a portion of the intensity distribution on the optical axis, the first pair of line segments being defined along a first direction in which a pattern extends and defined apart from the optical axis of the illumination optical system by a first distance corresponding to fineness of the pattern with respect to a second direction perpendicular to the first direction;
• and
• projecting onto the object through the projection optical system the illuminated pattern with light of which the intensity distribution has the increased intensity portions on the predetermined plane in the illumination optical system.