Patent ID: 9513558
Filing Date: 2016-12-06
CPC Classification: G03F

Claim Text:
1. An exposure apparatus that is configured to irradiate a substrate with light via a projection optical system and via a liquid, the exposure apparatus comprising: a stage that is configured to move relative to the projection optical system; an optical member that is provided on the stage and that comprises a first surface and a second surface, the first surface being arranged to come into contact with the liquid in a state of being moved to a position facing the projection optical system, the second surface being arranged to come into contact with a gas and to transmit light, having come from the projection optical system via the liquid and the first surface; and a light-receiving element that comprises a light-receiving surface, wherein the optical member is configured such that at least a large-angle ray of the light is able to travel from the projection optical system to the second surface without passing through any gas, the large-angle ray being defined as a ray of the light having an angle with an optical axis of the projection optical system sufficiently large so as to undergo total reflection at an end surface of the projection optical system when the liquid is absent, the second surface is configured to transmit at least the large-angle ray, and the light-receiving surface is arranged to receive at least the large-angle ray.