Electrostatic clamp, lithographic apparatus and method
AssigneeASML Netherlands B.V.
InventorsRonald Van Der Wilk, Roger Wilhelmus Antonius Henricus Schmitz, Arnoud Willem Notenboom, Manon Elise Will
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Abstract
An electrostatic clamp (21) configured to hold an object, the electrostatic clamp comprising an electrode (24), a resistive portion (23) formed from a resistive material located on the electrode, and a dielectric portion (22) formed from a dielectric material located on the resistive portion.
Claims8
A clamp configured to hold an object, the clamp comprising:
- an electrode to which a voltage may be applied in order to secure the object to the clamp;
- and
- a cooling fluid conduit having an inlet and an outlet,
- wherein the clamp is provided with a heater configured to locally heat part of the cooling fluid conduit, and
- wherein the heater is configured to locally heat part of the cooling fluid conduit that is only adjacent to the inlet, thereby reducing a temperature gradient between fluid adjacent to the inlet and fluid that is approaching the outlet.
A method of cooling a clamp configured to hold an object, the clamp including an electrode to which a voltage may be applied in order to secure the object to the clamp, the method comprising passing cooling fluid into an inlet of a cooling fluid conduit and removing hot cooling fluid from an outlet of the cooling fluid conduit, the method further comprising using a heater to locally heat the cooling fluid only adjacent to the inlet such that a temperature gradient between fluid adjacent to the inlet and fluid that is approaching the outlet is reduced.
Dependencies are inferred from the claim text.