Semiconductor exposure device using extreme ultra violet radiation
View Patent ↗The exposure device is able to supply only EUV radiation to a mask, while eliminating radiation other than the EUV radiation. A multi layer made from a plurality of Mo/Si pair layers is provided upon the front surface of a mirror, and blazed grooves are formed in this multi layer. Radiation which is incident from a light source device is incident upon this mirror, and is reflected or diffracted. Since the reflected EUV radiation (including diffracted EUV radiation) and the radiation of other wavelengths are reflected or diffracted at different angles, accordingly their directions of progression are different. By eliminating the radiation of other wavelengths with an aperture and/or a dumper, it is possible to irradiate a mask only with EUV radiation of high purity.
1. A semiconductor exposure device comprising:
an illumination optical system for directing EUV (extreme ultraviolet) light from an EUV light source to a mask; and
mirrors included in the illumination optical system, one of the mirrors comprising a multilayered reflecting coating with grooves and being configured for reflecting the EUV light from the EUV light source to direct the EUV light to the mask, the grooves being arranged in a concentric fashion, wherein
the EUV light source is configured for irradiating a target with laser light from a driver laser to turn the target into plasma from which the EUV light is emitted, and
the grooves are configured for diffracting at least light at a wavelength which is the same as that of the laser light from the drive laser.
2. The semiconductor exposure device according to claim 1 , wherein the one of the mirrors is a collimator mirror.
3. The semiconductor exposure device according to claim 2 , wherein the grooves are arranged concentrically with respect to a center of the collimator mirror.
4. The semiconductor exposure device according to claim 1 , wherein the one of the mirrors is placed to first receive the EUV light from the EUV light source.
5. The semiconductor exposure device according to claim 1 , wherein the wavelength of the light to be diffracted by the grooves is approximately 10.6 μm.
6. The semiconductor exposure device according to claim 1 , wherein the driver laser is a carbon dioxide (CO 2 ) laser.
7. The semiconductor exposure device according to claim 1 , wherein a distance between a nadir of one groove and that of an adjacent groove is in a range of 1.54 μm to 400 μm.
8. The semiconductor exposure device according to claim 1 , wherein a distance between a nadir of one groove and that of an adjacent groove is in a range of 400 μm to 800 μm.
9. The semiconductor exposure device according to claim 1 , wherein a distance between a nadir of one groove and that of an adjacent groove is in a range of 1.54 μm to 800 μm.
10. The semiconductor exposure device according to claim 1 , further comprising a dumper for light to be diffracted by the grooves.
11. The semiconductor exposure device according to claim 10 , further comprising a cooling device for cooling the dumper.
12. The semiconductor exposure device according to claim 10 , wherein the wavelength of the light to be diffracted by the grooves is approximately 10.6 μm.
13. The semiconductor exposure device according to claim 10 , wherein the light to be diffracted by the grooves is laser light from a carbon dioxide (CO 2 ) laser for generating the EUV light.
14. The semiconductor exposure device according to claim 1 , wherein the multilayered reflecting coating comprises 100 to 1000 pairs of stacked Mo/Si layers.
15. The semiconductor exposure device according to claim 1 ,
wherein
the multilayered reflecting coating comprises pairs of stacked Mo/Si layers, and
a nadir of each groove reaches approximately 250th to 300th pair of the stacked Mo/Si layers from a surface of the one of the mirrors.
16. The semiconductor exposure device according to claim 1 ,
wherein
the one of the mirrors comprises a substrate having the multilayered reflecting coating thereon,
the multilayered reflecting coating comprises pairs of stacked Mo/Si layers, and
the multilayered reflecting coating includes approximately 50 pairs of the stacked Mo/Si layers between the nadir and the substrate.
17. The semiconductor exposure device according to claim 1 , further comprising a surface coating on a surface of the multilayered reflecting coating.
18. The semiconductor exposure device according to claim 17 , wherein a material of the surface coating includes ruthenium.