Exposure apparatus, light source apparatus and device fabrication
An exposure apparatus for exposing a pattern of a mask onto an object, said exposure apparatus includes a light source for generating a plasma, said light source including a condenser mirror that condenses a light irradiated from the plasma, an illumination optical system for illuminating the mask using the light condensed by the condenser mirror, a detector that is provided between the condenser mirror and the illumination optical system, said detector detecting a property of the light, and a changing part for changing a state of the plasma based on a detected result of the detector.
1. An exposure apparatus for exposing a pattern of a mask onto an object, said exposure apparatus comprising:
a light source for generating a plasma, said light source including a condenser mirror that condenses a light irradiated from the plasma;
an illumination optical system for illuminating the mask using the light condensed by the condenser mirror;
a detector that is provided between the condenser mirror and the illumination optical system, said detector detecting a property of the light; and
a changing part for changing a state of the plasma based on a detected result of the detector.
2. An exposure apparatus according to claim 1 , wherein said property of the light is at least one of a position of a condensing point of the light, a light intensity distribution within a divergence angle divergent from the condensing point, a spectrum of the light, and a light intensity on the condensing point.
3. An exposure apparatus according to claim 1 , wherein said changing part changes at least one of a position of the plasma and an electron temperature of the plasma.
4. An exposure apparatus according to claim 1 , wherein said detector detects the property of the light at a predetermined time interval.
5. An exposure apparatus according to claim 1 , wherein said detector always detects the property of the light when the plasma is generated.
6. An exposure apparatus according to claim 1 , wherein said detector is provided between a condensing point of the light and the illumination optical system.
7. An exposure apparatus according to claim 1 , wherein said light has a wavelength of 20 nm or less.