US 12,072,620 B2
Method of manufacturing a membrane assembly
Pieter-Jan Van Zwol, Eindhoven (NL); Sander Baltussen, Castenray (NL); Dennis De Graaf, Waalre (NL); Johannes Christiaan Leonardus Franken, Knegsel (NL); Adrianus Johannes Maria Giesbers, Vlijmen (NL); Alexander Ludwig Klein, Eindhoven (NL); Johan Hendrik Klootwijk, Eindhoven (NL); Peter Simon Antonius Knapen, Deurne (NL); Evgenia Kurganova, Nijmegen (NL); Alexey Sergeevich Kuznetsov, Zaltbommel (NL); Arnoud Willem Notenboom, Rosmalen (NL); Mahdiar Valefi, Eindhoven (NL); Marcus Adrianus Van de Kerkhof, Helmond (NL); Wilhelmus Theodorus Anthonius Johannes Van den Einden, Deurne (NL); Ties Wouter Van der Woord, Eindhoven (NL); Hendrikus Jan Wondergem, Veldhoven (NL); and Aleksandar Nikolov Zdravkov, Eindhoven (NL)
Assigned to ASML NETHERLANDS B.V., Veldhoven (NL)
Appl. No. 17/278,356
Filed by ASML NETHERLANDS B.V., Veldhoven (NL)
PCT Filed Oct. 2, 2019, PCT No. PCT/EP2019/076667
§ 371(c)(1), (2) Date Mar. 22, 2021,
PCT Pub. No. WO2020/078721, PCT Pub. Date Apr. 23, 2020.
Claims priority of application No. 18200397 (EP), filed on Oct. 15, 2018; and application No. 19180527 (EP), filed on Jun. 17, 2019.
Prior Publication US 2022/0035239 A1, Feb. 3, 2022
Int. Cl. G03F 1/64 (2012.01); G03F 7/00 (2006.01)
CPC G03F 1/64 (2013.01) [G03F 7/7015 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A membrane assembly for EUV lithography, the membrane assembly comprising:
a membrane formed from at least one membrane layer comprising polycrystalline silicon or monocrystalline silicon; and
a border holding the membrane,
wherein the border is formed from a planar substrate comprising an inner region and a border region around the inner region,
wherein the border resulted from selective removal of the inner region of the planar substrate,
wherein the planar substrate supports the at least one membrane layer and a sacrificial layer such that the border supports the at least one membrane layer and the sacrificial layer, each of the planar substrate, sacrificial layer and at least one membrane layer being of a different material,
wherein the sacrificial layer is between the planar substrate and the at least one membrane layer, and
wherein an etch rate of an etchant of the planar substrate and the at least one membrane layer is different to the etch rate of the etchant of the sacrificial layer and the etch rate of the etchant of the sacrificial layer is at least ten times more than the etch rate of the etchant of the at least one membrane layer.