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US 8,711,323 B2Granted
Lithographic apparatus and device manufacturing method
AssigneeASML Netherlands B.V.
InventorsBob Streefkerk, Antonius Theodorus Anna Maria Derksen, Joeri Lof, Klaus Simon, Alexander Straaijer
Life of this patent
Estimating the term…
Abstract
An immersion lithography apparatus comprises a temperature controller configured to adjust a temperature of a projection system, a substrate and a liquid towards a common target temperature. Controlling the temperature of these elements and reducing temperature gradients may improve imaging consistency and general lithographic performance. Measures to control the temperature may include controlling the immersion liquid flow rate and liquid temperature, for example, via a feedback circuit.
Claims20
An exposure apparatus comprising:
- a projection optical system to project a pattern of a reticle onto a substrate, said projection optical system including an optical element closest to the substrate;
- a liquid supply system to supply a liquid to a space between the optical element and the substrate, the liquid supply system comprising a liquid confinement member extending at least partly between the optical element and the substrate and spaced apart from and out of direct contact with the optical element, the liquid confinement member having:
- a surface, extending around the space and facing toward the substrate, defining the space with a cross-sectional area smaller than the area of the pattern receiving surface of the substrate,
- an inlet to supply the liquid,
- an outlet in the surface to exhaust the liquid, and
- an open aperture between the optical element and the substrate to allow fluid connection between the optical element and the substrate, the open aperture having a width smaller than a bottom surface of the optical element;
- a temperature controller to control a temperature of the liquid, wherein (a) said temperature controller controls the temperature of the liquid based on temperature information at a plurality of locations on or adjacent (i) the substrate, or (ii) the optical element, or (iii) both (i) and (ii), or (b) a projection optical system compensator adjusts an optical property of the projection optical system based on temperature information at a plurality of locations on or adjacent (iv) the substrate, or (v) the optical element, or (vi) both (iv) and (v), or (c) both (a) and (b);
- and
- a stage to move the substrate relative to the optical element and the liquid confinement member.
6 more elements
An exposure apparatus comprising:
- a projection optical system to project a pattern of a reticle onto a substrate;
- a holder to hold the substrate;
- a liquid supply system to supply a liquid to a space between the projection optical system and the holder, the liquid supply system comprising a liquid confinement member extending at least partly between the projection optical system and the holder and spaced apart from and out of direct contact with the projection optical system, the liquid confinement member having:
- a surface, extending around the space and facing toward the substrate, defining the space with a cross-sectional area smaller than the area of the pattern receiving surface of the substrate,
- an inlet to supply the liquid,
- an outlet in the surface to exhaust the liquid, and
- an open aperture between the projection optical system and the substrate to allow fluid connection between the projection optical system and the substrate, the open aperture having a width smaller than a bottom surface of the projection optical system;
- a temperature controller to supply a liquid that has been temperature-controlled, to the space, wherein (a) said temperature controller controls the temperature of the liquid based on temperature information at a plurality of locations on or adjacent (i) the substrate, or (ii) a part of the projection optical system in contact with the liquid, or (iii) both (i) and (ii), or (b) a projection optical system compensator adjusts an optical property of the projection optical system based on temperature information at a plurality of locations on or adjacent (iv) the substrate, or (v) a part of the projection optical system in contact with the liquid, or (vi) both (iv) and (v), or (c) both (a) and (b);
- a temperature sensor to measure the temperature information at the plurality of locations on (vii) the substrate, or (viii) the part of the projection optical system in contact with the liquid, or (ix) both (vii) and (viii);
- and
- a stage to move the substrate relative to the projection optical system and the liquid confinement member.
8 more elements
Dependencies are inferred from the claim text.