Large area interference lithography using a table-top extreme ultraviolet laser: a systematic study of the degree of mutual coherence.
A prototype low cost table-top Ar capillary discharge laser source (1.5 ns pulse duration, lambda = 46.9 nm) was successfully used to produce, by means of interference lithography (with a simple Lloyd mirror setup), large area (0.1 mm(2)) regular patterns from 400 nm down to 22.5 nm (half-pitch) on PMMA/Si (PMMA: polymethylmethacrylate) substrates. The experiments allowed a systematical investigation of the degree of mutual coherence of the source, giving a clear indication that the interference lithography can be pushed down to the ultimate resolution limit of lambda/4.
Dipartimento di Fisica, Università dell'Aquila, L'Aquila, Italy.
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P
Zuppella
D
D
Luciani
P
P
Tucceri
P
P
De Marco
A
A
Gaudieri
J
J
Kaiser
L
L
Ottaviano
S
S
Santucci
A
A
Reale