Patent ID: 11914282
Assignee: SAMSUNG ELECTRONICS CO., LTD.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 4:
5. The system of claim 1, wherein all of the zone-plate lens, the order sorting aperture, and the reflection-type EUV mask are disposed in a horizontal structure,
the order sorting aperture is a pin-hole and is placed between the zone-plate lens and the EUV mask to transmit only the first-order diffraction light, among light focused on the EUV mask through the zone-plate lens, and
a distance between the order sorting aperture and the reflection-type EUV mask is configured to be smaller than ⅛ of a distance between the zone-plate lens and the reflection-type EUV mask and to reduce a noise component, except for a focusing component, to a level smaller than 4%.