Patent ID: 9618835
Date: 2017-04-11
CPC Classifications: G03B

Claim:
1. A lithographic apparatus comprising: a substrate table arranged to hold a substrate and scan the substrate in a scanning direction; a projection system arranged to project a radiation beam onto the substrate while the substrate is scanned by the substrate table; and a liquid confinement system arranged to confine a liquid to a space between the projection system and the substrate; and a liquid supply opening configured to supply the liquid to the space, wherein the projection system has an optical axis and is arranged to project the radiation beam into an image field having a maximum cross-wise dimension, in a direction perpendicular to the optical axis and the scanning direction, that is smaller than a maximum cross-wise dimension, in the direction, of a portion of the space containing the liquid, the liquid confinement system has a liquid confinement member bordering the portion of the space containing the liquid, the liquid confinement member having a liquid supply orifice defined in a surface thereof, the liquid supply orifice having a continuous, elongate cross-section in the surface that does not surround the optical axis and is separate from the liquid supply opening, the liquid supply orifice arranged to direct the liquid toward the substrate and the elongate cross-section having a cross-wise dimension in the direction that is greater than the maximum cross-wise dimension of the image field and less than a maximum cross-wise dimension, in the direction, of the portion containing the liquid, the liquid confinement system is configured to provide the liquid from the liquid supply orifice at a higher pressure than that of the liquid in the portion of the space containing the liquid, the liquid confinement member defines an open aperture through which the radiation beam is arranged to pass and through which the liquid from the liquid supply opening is arranged to pass from above the aperture to below the aperture, and the liquid confinement member comprises an exhaust orifice defined in an exterior surface of the liquid confinement member, the exhaust orifice located outward, relative to a path of the radiation beam through the space, of the liquid supply orifice and a cross-section of the exhaust orifice facing toward the substrate table, the exhaust orifice configured to remove at least part of the liquid supplied from the liquid supply opening.