Supporting structure of optical element, exposure apparatus having the same, and manufacturing method of semiconductor device
A supporting structure for supporting an optical element includes a first supporting member for supporting the optical element, and a second supporting member for supporting the first supporting member. The value of a thermal expansion coefficient of the first supporting member is between those of the optical element and the second supporting member.
1. A supporting structure for supporting an optical element, said supporting structure comprising:
a supported member including the optical element; and
a supporting member for supporting said supported member via a plurality of elastic members, each of which comprises a spring member, having elasticity in a radial direction of the optical element.
2. A structure according to claim 1 , wherein said spring member comprises a plate-shaped spring member.
3. A structure according to claim 1 , wherein each of said plurality of elastic members is contacted with an outer surface of said supported member and an inner surface of said supporting member.
4. A structure according to claim 1 , wherein said plurality of elastic members are disposed at intervals along a periphery of said supported member.
5. An exposure apparatus for exposing a wafer to light via a reticle, said apparatus comprising:
an illuminating optical system for illuminating the reticle with light from a light source; and
a projection optical system for projecting light from the reticle onto the wafer,
wherein at least one of said illuminating optical system and said projection optical system comprises a supporting structure, as defined in claim 1 , for supporting an optical element.
6. A method of manufacturing a semiconductor device, said method comprising steps of:
providing a reticle and a wafer into an exposure apparatus as defined in claim 5 ; and
exposing the wafer to light using the exposure apparatus.