US 11,898,970 B2
EUV mask inspection device using multilayer reflection zone plate
Dong Gun Lee, Hwaseong-si (KR)
Assigned to ESOL Inc., Hwaseong-si (KR)
Filed by ESOL Inc., Hwaseong-si (KR)
Filed on Jan. 7, 2022, as Appl. No. 17/570,407.
Claims priority of application No. 10-2021-0137574 (KR), filed on Oct. 15, 2021.
Prior Publication US 2023/0121748 A1, Apr. 20, 2023
Int. Cl. G01N 21/55 (2014.01); G01N 21/956 (2006.01); G03F 1/22 (2012.01)
CPC G01N 21/956 (2013.01) [G01N 21/55 (2013.01); G03F 1/22 (2013.01); G01N 2021/95676 (2013.01)] 9 Claims
OG exemplary drawing
 
1. An EUV mask inspection device using a multilayer reflection zone plate for metrology and inspection of an EUV mask used in an EUV exposure process during a semiconductor device manufacturing process, which comprises: an EUV light source for outputting EUV light with a wavelength ranging from 5 nm to 15 nm; a multilayer reflection zone plate having an EUV reflection multilayer film, which is a planar substrate, and a zone plate pattern; and an EUV lighting unit for creating EUV illumination light by obtaining 1st diffraction light reflected after radiating EUV light output from the EUV light source to the multilayer reflection zone plate, and the EUV mask inspection device comprising:
an aperture for providing monochromatic light or reducing a light radiation area by reducing a linewidth of optical wavelength radiated from the EUV lighting unit;
a transmissive zone plate for forming expanded light by collecting reflected or scattered light after radiating light passing through the aperture to the EUV mask; and
an image sensor for measuring intensity of light through EUV mask measured light, which is the light passing through the transmissive zone plate.