US 12,282,144 B2
High-performance EUV microscope device with free-form illumination system structure
Dong Gun Lee, Hwaseong-si (KR)
Assigned to ESOL Inc., Hwaseong-si (KR)
Filed by ESOL Inc., Hwaseong-si (KR)
Filed on Jan. 15, 2023, as Appl. No. 18/097,242.
Claims priority of application No. 10-2022-0186631 (KR), filed on Dec. 28, 2022.
Prior Publication US 2024/0219699 A1, Jul. 4, 2024
Int. Cl. G03F 7/20 (2006.01); G02B 21/00 (2006.01); G02B 21/36 (2006.01); G03F 7/00 (2006.01)
CPC G02B 21/0048 (2013.01) [G02B 21/0032 (2013.01); G02B 21/36 (2013.01); G03F 7/70133 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A high performance EUV microscope device with a freeform illumination system comprising:
an EUV source for outputting EUV light;
a spherical mirror having a two-axis driving unit which receives and reflects the EUV light output from the EUV light source and controls a reflection direction of the incident light through two-axis angle scanning;
an optical path changing means for receiving the reflected light reflected from the spherical mirror and providing illumination light to a target object to be measured, wherein the optical path changing means comprises:
one plane mirror receiving the reflected light reflected from the spherical mirror to determine an angle of the illumination light provided to the target object to be measured; and
an elliptical mirror forming freeform illumination light through the plane mirror to be incident to the target object,
wherein the optical path changing means selectively controls a reflection angle of the spherical mirror and a reflection angle of the plane mirror to determine a reflection angle;
a zone plate lens for focusing the light reflected after entering the target object; and
a photodetector for receiving the light focused by the zone plate lens,
wherein the spherical mirror is rotated by the driving unit to control the reflection direction of the reflected light, and a spot position of the illumination light irradiated to the target object is controlled by the optical path changing means receiving the reflected light.