US 12,306,551 B2
Projection exposure apparatus having a device for determining the concentration of atomic hydrogen
Dirk Ehm, Beckingen (DE); and Moritz Becker, Aalen (DE)
Assigned to CARL ZEISS SMT GMBH, Oberkochen (DE)
Filed by Carl Zeiss SMT GmbH, Oberkochen (DE)
Filed on Mar. 23, 2022, as Appl. No. 17/702,218.
Claims priority of application No. 10 2021 202 802.0 (DE), filed on Mar. 23, 2021.
Prior Publication US 2022/0308457 A1, Sep. 29, 2022
Int. Cl. G03F 7/00 (2006.01); G01N 33/00 (2006.01)
CPC G03F 7/7085 (2013.01) [G01N 33/005 (2013.01); G03F 7/70308 (2013.01)] 19 Claims
OG exemplary drawing
 
1. Projection exposure apparatus for semiconductor lithography, comprising a device for determining concentration of atomic hydrogen in a plasma in a region of an optical element, wherein the device comprises:
a sensor, and
a filter element arranged between the region of the plasma and the sensor, wherein the filter element is configured to predominantly allow passage of atomic hydrogen from the plasma to the sensor, and
wherein the filter element comprises a channel-shaped region for the passage of the atomic hydrogen.