US 11,692,948 B2
Inspection apparatus and inspection method
Nitish Kumar, Eindhoven (NL); Richard Quintanilha, Heidenheim an der Brenz (DE); Markus Gerardus Martinus Maria Van Kraaij, Eindhoven (NL); Konstantin Tsigutkin, Eindhoven (NL); and Willem Marie Julia Marcel Coene, Geldrop (NL)
Assigned to ASML NETHERLANDS B.V., Veldhoven (NL)
Appl. No. 16/963,905
Filed by ASML NETHERLANDS B.V., Veldhoven (NL)
PCT Filed Jan. 8, 2019, PCT No. PCT/EP2019/050306
§ 371(c)(1), (2) Date Jul. 22, 2020,
PCT Pub. No. WO2019/149477, PCT Pub. Date Aug. 8, 2019.
Claims priority of application No. 18154116 (EP), filed on Jan. 30, 2018.
Prior Publication US 2020/0348244 A1, Nov. 5, 2020
Int. Cl. G01N 21/956 (2006.01); G02F 1/35 (2006.01); G03F 1/84 (2012.01)
CPC G01N 21/956 (2013.01) [G02F 1/353 (2013.01); G03F 1/84 (2013.01); G01N 2021/95676 (2013.01); G01N 2201/06113 (2013.01)] 20 Claims
OG exemplary drawing
 
14. An inspection apparatus to inspect a substrate for a reflective reticle, wherein the substrate is configured to be illuminated by radiation having an actinic wavelength to expose a pattern from the reticle, the inspection apparatus comprising:
a high harmonic generation source configured to output inspection radiation having one or more wavelengths within a wavelength range of between 20 nm and 150 nm and the one or more wavelengths being approximately an integer multiple, other than 1, of the actinic wavelength;
an optical element configured to receive the inspection radiation and provide the inspection radiation to a surface of the substrate for the reflective reticle; and
a detector configured to detect radiation from the substrate for detecting defects on the substrate.