Patent ID: 9280050
Filing Date: 2016-03-08
CPC Classification: G03F

Claim Text:
1. An exposure apparatus which exposes a substrate, the apparatus comprising: an illumination optical system configured to illuminate a mask using light from a light source; a projection optical system configured to irradiate the substrate with light from a pattern on the mask; an adjustment unit configured to adjust an oxygen concentration in a space between the projection optical system and the substrate; a measuring unit configured to measure an illuminance of light applied to the substrate; and a control unit configured to control the measuring unit so as to measure illuminances of light applied to the substrate a plurality of times during irradiation of the substrate with light from the projection optical system, configured to calculate, based on the illuminance measured on a first time of the plurality of times, an oxygen concentration value corresponding to the measured illuminance on the first time and calculate, based on the illuminance measured on a second time of the plurality of times, an oxygen concentration value corresponding to the measured illuminance on the second time and configured to control the adjustment unit so as to set the oxygen concentration in the space to the calculated oxygen concentration value on the first time and the second time.