Patent ID: 7551262

Claim:
An exposure apparatus comprising: (a) a projection optical system configured to project a pattern of a reticle onto each of a plurality of shots on a wafer; (b) a wafer stage configured to hold the wafer and to move; and (c) a position detection system including: (i) an irradiation unit configured to irradiate light obliquely incident onto a surface of the wafer; (ii) a detector configured to detect the light reflected onto the wafer from said irradiation unit; (iii) a selector configured to select a wavelength of light which said irradiation unit irradiates, based on a result detected by said detector; and (iv) a calculator configured to calculate heights of a plurality of places in each of the plurality of shots, based on a result detected by said detector, wherein said position detecting system has a selecting mode for selecting a wavelength of light which said irradiation unit irradiates, and a measuring mode for measuring a height of each of the plurality of places in the plurality of shots by using the wavelength of light selected by the selecting mode, wherein, in the selecting mode, said irradiation unit irradiates a plurality of lights having different wavelengths onto each of a first place and a second place, which is different from the first place in a first shot, and said selector selects a first light among the plurality of lights in the first place, and selects a second light which has a different wavelength from the first light among the plurality of lights in the second place, wherein, in the measuring mode, said irradiation unit irradiates the first light onto a third place corresponding to the first place in a second shot which is different from the first shot, and irradiates the second light onto a fourth place corresponding to the second place in the second shot.