EUV LITHOGRAPHY SYSTEM FOR DENSE LINE PATTERNING

Extreme ultra-violet (EUV) lithography ruling engine specifically configured to print one-dimensional lines on a target workpiece includes source of EUV radiation; a pattern-source defining 1D pattern; an illumination unit (IU) configured to irradiate the pattern-source; and projection optics (PO) configured to optically image, with a reduction factor N>1, the 1D pattern on image surface that is optically-conjugate to the 1D pattern. Irradiation of the pattern-source can be on-axis or off-axis. While 1D pattern has first spatial frequency, its optical image has second spatial frequency that is at least twice the first spatial frequency. The pattern-source can be flat or curved. The IU may include a relay reflector. A PO's reflector may include multiple spatially-distinct reflecting elements aggregately forming such reflector. The engine is configured to not allow formation of optical image of any 2D pattern that has spatial resolution substantially equal to a pitch of the 1D pattern of the pattern-source.