Illuminating optical system

Claim 2

An illuminating optical system for illuminating an object, said optical system comprising: light source means for selectively producing light having a desired wavelength; a multi-beam generating optical element for receiving the light having a desired wavelength produced by said light source means, and for forming a plurality of light sources that emit light as multiple beams; a stationary collimator lens for directing the multiple beams emitted from said multi-beam generating optical element to the object; and means for changing an optical path between said plurality of light sources and said stationary collimator lens so as to coincide the position of said plurality of light sources with a focus position of said collimator lens.

Claim 3

An illuminating optical system according to claim 1, wherein said multi-beam generating optical element is movable by said changing means in at least one of a direction to shorten the distance between said multi-beam generating optical element and said collimator lens and a direction to lengthen said distance.

Claim 4

An illuminating optical system according to claim 1, wherein said changing means includes a light-transmitting flat plate which is removably disposed between said element and said collimator lens.

Claim 5

An illuminating optical system according to claim 1, wherein said multi-beam generating optical element is a fly's eye lens.

Claim 6

An illuminating optical system for illuminating a mask to transfer a pattern thereon to a wafer, comprising: light providing means for providing light; wavelength changing means for changing the wavelength of light provided by said light providing means; multi-beam forming means for forming multiple beams utilizing light provided by said light providing means; optical means for illuminating the mask with light from the multiple beams formed by said multi-beam forming means to transfer the pattern on the mask to the wafer; and position changing means for changing a position of said multi-beam forming means relative to said optical means in accordance with the wavelength of the light provided by said light providing means as determined by said wavelength changing means, so as to minimize the illumination distribution on the mask.

Claim 7

An illuminating optical system for illuminating a mask to transfer a pattern thereon to a wafer, comprising: light providing means for providing light; wavelength changing means for changing the wavelength of light provided by said light providing means; multi-beam forming means for forming multiple beams utilizing light provided by said light providing means; optical means for illuminating the mask with light from the multiple beams formed by said multi-beam forming means to transfer the pattern on the mask to the wafer; and position changing means for changing a position of said multi-beam forming means relative to said optical means in accordance with the wavelength of the light provided by said light providing means as determined by said wavelength changing means, so as to minimize the illumination distribution on the mask.

Claim 8

An illuminating optical system according to claim 5, wherein said multi-beam forming means includes a fly's eye lens.

Claim 9

An illuminating optical system according to claim 6, wherein said position changing means includes means for moving said fly's eye lens in a direction of the optical axis of said optical means so as to maintain the position of divergent points of the multiple beams formed by said multi-beam forming means at a focal plane of said optical means.

Claim 10

An illuminating optical system according to claim 5 wherein said position changing means includes a light-transmitting flat plate which is removably disposed between said multi-beam forming means and said optical means.

Claim 11

An illuminating optical system for illuminating a mask for transferring a pattern thereon to a wafer, comprising: light providing means for providing light; wavelength changing means for changing the wavelength of the light provided by said light providing means; multi-beam forming means for forming multiple beams utilizing light provided by said light providing means; optical means for illuminating the mask with light from the multiple beams formed by said multi-beam forming means to transfer the pattern on the mask to the wafer; and position changing means for changing the position of said multi-beam forming means relative to said optical means in accordance with the wavelength of the light provided by said light providing means as determined by said wavelength changing means, so as to maintain the angle of inclination of principal rays of said multiple beams directed to the mask substantially the same.

Claim 12

An illuminating optical system for illuminating a mask for transferring a pattern thereon to a wafer, comprising: light providing means for providing light; wavelength changing means for changing the wavelength of the light provided by said light providing means; multi-beam forming means for forming multiple beams utilizing light provided by said light providing means; optical means for illuminating the mask with light from the multiple beams formed by said multi-beam forming means to transfer the pattern on the mask to the wafer; and position changing means for changing the position of said multi-beam forming means relative to said optical means in accordance with the wavelength of the light provided by said light providing means as determined by said wavelength changing means, so as to maintain the angle of inclination of principal rays of said multiple beams directed to the mask substantially the same.

Claim 13

An illuminating optical system according to claim 9, wherein said wavelength changing means comprises a wavelength filter for selectively filtering light of a desired wavelength from light including a plurality of wavelengths.

Claim 14

An illuminating optical system according to claim 9, wherein said light providing means includes a light source and an ellipitical mirror for directing light from said light source to said multi-beam forming means.

Claim 15

An illuminating optical system according to claim 9, wherein said optical means includes lens means for superimposing multiple beams from said multi-beam forming means on the mask.

Claim 16

An illuminating optical system according to claim 9, wherein said optical means includes lens means for directing light from said multi-beam forming means onto the mask.

Claim 17

An illuminating optical system according to claim 13, wherein said position changing means comprises means for changing a position of divergent points of the multiple beams, formed by said multi-beam forming means, in a direction of an optical axis of said lens means.

Claim 18

An illuminating optical system according to claim 9, wherein said position changing means comprises moving means for moving said multi-beam forming means in a direction of an optical axis thereof.

Claim 19

An illuminating optical system according to claim 9, wherein said optical means illuminates the mask with a parallel light beam.

Claim 20

An illuminating optical system for illuminating a mask to transfer a pattern thereon to a wafer, comprising: means for providing light having a desired wavelength; optical means for illuminating the mask with light provided by said light providing means to transfer the pattern on the mask to the wafer; and controlling means for maintaining constant the angle of inclination of a principal ray of the light directed to the mask when the wavelength of the light provided by said providing means changes.

Claim 21

An illuminating optical system for illuminating a mask to transfer a pattern thereon to a wafer, comprising: means for providing light having a desired wavelength; optical means for illuminating the mask with light provided by said light providing means to transfer the pattern on the mask to the wafer; and controlling means for maintaining constant the angle of inclination of a principal ray of the light directed to the mask when the wavelength of the light provided by said providing means changes.

Claim 22

An illuminating optical system for illuminating a mask for transferring a pattern thereon to a wafer, comprising: light source means for providing light having a desired wavelength; optical means for illuminating the mask with light provided by said light source means to transfer the pattern on the mask to the wafer; and means for minimizing the change of the illumination distribution on the mask when the wavelength of light provided by said light source means changes.

Claim 23

An illuminating optical system for illuminating a mask for transferring a pattern thereon to a wafer, comprising: light source means for providing light having a desired wavelength; optical means for illuminating the mask with light provided by said light source means to transfer the pattern on the mask to the wafer; and means for minimizing the change of the illumination distribution on the mask when the wavelength of light provided by said light source means changes.