RETICLE COOLING IN LITHOGRAPHY DEVICE

PROBLEM TO BE SOLVED: To provide a device and a method of reducing temperature variation over a reticle so that variation in expansion of the reticle is reduced.SOLUTION: One method of achieving reduced temperature variation is to fill the internal space with pressurized backfill gas by using a distribution trench and wall (e.g. a flow restriction dam) rather than providing uniform backfill gas pressure over the entire reticle. In a different method, outer periphery of the internal space may be selected to reduce variation in expansion over the reticle based on the functional relation between expansion and temperature for a reticle material. In an arbitrary or alternative method, reduced variation in expansion over the reticle can be obtained by filling the cavity in a chuck cooled by fluid selectively with backfill gas.