US 12,436,472 B2
Cooling hood for reticle
Marcus Adrianus Van De Kerkhof, Helmond (NL); and Victor Antonio Perez-Falcon, Golden, CO (US)
Assigned to ASML Netherlands B.V., Veldhoven (NL)
Appl. No. 18/570,242
Filed by ASML Netherlands B.V., Veldhoven (NL)
PCT Filed May 27, 2022, PCT No. PCT/EP2022/064478
§ 371(c)(1), (2) Date Dec. 14, 2023,
PCT Pub. No. WO2022/263148, PCT Pub. Date Dec. 22, 2022.
Claims priority of provisional application 63/210,394, filed on Jun. 14, 2021.
Prior Publication US 2024/0288783 A1, Aug. 29, 2024
Int. Cl. G03F 7/00 (2006.01)
CPC G03F 7/70875 (2013.01) [G03F 7/70358 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A lithographic apparatus, comprising:
an optical system configured to direct a radiation beam onto a reticle supported by a reticle table to form a patterned radiation beam, wherein the radiation beam causes heating of an exposed area of the reticle; and
a reticle cooling apparatus configured to remove heat from the reticle, wherein the reticle cooling apparatus comprises:
a cooling element disposed below the reticle and adjacent to the exposed area, wherein:
the cooling element comprises a body comprising a chamber connected to a channel configured to deliver gas to the chamber, and
a roof of the chamber is disposed adjacent to the reticle and comprises openings configured to output the gas towards the reticle;
actuators configured to modify a distance between the roof and the reticle; and
a cooling controller configured to:
generate a cooling control signal based on timing data for a projection of the patterned radiation beam, absorption data for the exposed area on the reticle, and a target heat transfer rate, wherein the cooling control signal is configured to instruct the reticle cooling apparatus to actuate the actuators to modify the distance between the roof and the reticle; and
transmit the cooling control signal to the actuators.