Fluid handling structure, lithographic apparatus and a device manufacturing method

A fluid handling structure configured to supply immersion liquid to a space defined between a projection system and a facing surface facing the fluid handling system, wherein an undersurface of the fluid handling structure has:

• a supply opening configured to supply fluid toward the facing surface;
• and
• a protrusion radially inward with respect to an optical axis of the projection system of the supply opening.

A fluid handling structure configured to supply immersion liquid to a space between a projection system and a facing surface facing the fluid handling system, wherein formed in an undersurface of the fluid handling structure is:

• a supply opening to supply immersion liquid towards the facing surface;
• and
• a step in the surface of the undersurface radially outward of the supply opening with respect to a geometric center of the undersurface, the step configured to reduce the radially outward flow of immersion liquid from the space.

A device manufacturing method comprising:

• providing a fluid between a final element of a projection system and a substrate;
• wherein the providing includes supplying liquid towards the substrate through a supply opening in an undersurface of the fluid handling structure and removing fluid from between the fluid handling structure and the substrate and/or substrate table through an extraction opening in the undersurface of the fluid handling structure, wherein a protrusion is provided on the undersurface between the supply opening and the extraction opening.