Lithographic apparatus, device manufacturing method and method of calibrating a lithographic apparatus
AssigneeASML Netherlands B.V.
InventorsKoen Jacobus Johannes Maria Zaal, Johannes Henricus Wilhelmus Jacobs, Erik Roelof Loopstra, Joost Jeroen Ottens, Frederik Eduard De Jong
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Abstract
An immersion lithographic apparatus has a plurality of substrate holders arranged to hold substrates, each substrate holder having a conduit therein for passing a temperature control fluid. The thermal responses of the different substrate holders are calibrated and flow rates calculated and used so that all the holders return to a predetermined temperature in the same time.
Claims8
A lithographic apparatus for projecting an image of a desired pattern through a liquid onto substrates, the apparatus comprising:
- a plurality of substrate holders, each substrate holder being arranged to hold at least one substrate and having a conduit therein for passing a temperature control fluid;
- a fluid supply system arranged to supply temperature control fluid substantially at a predetermined temperature;
- a flow controller arranged to control the rates of flow of temperature control fluid in each of the substrate holders so that the flow rate in a first one of the substrate holders is different from the flow rate in a second one of the substrate holders;
- and
- a temperature control system arranged between the fluid supply system and the substrate holders when a respective substrate holder is in position to hold the substrate during projection of the image through the liquid, the temperature control system comprising
- a heater arranged to heat the temperature control fluid;
- a first temperature sensor arranged to measure the temperature of the temperature control fluid entering the respective substrate holder,
- a second temperature sensor arranged to measure the temperature of the temperature control fluid exiting the respective substrate holder, and
- a temperature controller arranged to receive temperature measurements from the first temperature sensor and the second temperature sensor and to control the heater based on the temperature measurements.
A device manufacturing method in which an image of a desired pattern is projected through a liquid onto a substrate using a lithographic apparatus having a plurality of substrate holders, the method comprising:
- passing a temperature control fluid substantially at a predetermined temperature through a conduit in each of the substrate holders during exposure of a substrate held on the respective substrate holder,
- the flow rate of the temperature control fluid in at least one of the substrate holders being different from the flow rate in another of the substrate holders;
- and
- supplying heat to the respective substrate holder between completion of exposure of a last substrate of a lot and loading of a first substrate of a new lot.
Dependencies are inferred from the claim text.