<s>
Interference	B-Algorithm
lithography	I-Algorithm
(	O
or	O
holographic	B-Algorithm
lithography	I-Algorithm
)	O
is	O
a	O
technique	O
for	O
patterning	O
regular	O
arrays	O
of	O
fine	O
features	O
,	O
without	O
the	O
use	O
of	O
complex	O
optical	B-Algorithm
systems	O
or	O
photomasks	B-Algorithm
.	O
</s>
<s>
The	O
basic	O
principle	O
is	O
the	O
same	O
as	O
in	O
interferometry	O
or	O
holography	B-Algorithm
.	O
</s>
<s>
Upon	O
post-exposure	O
photolithographic	B-Algorithm
processing	O
,	O
a	O
photoresist	O
pattern	O
corresponding	O
to	O
the	O
periodic	O
intensity	O
pattern	O
emerges	O
.	O
</s>
<s>
With	O
multi	O
wave	O
interference	O
(	O
by	O
inserting	O
a	O
diffuser	O
into	O
the	O
optical	B-Algorithm
path	O
)	O
aperiodic	O
patterns	O
with	O
defined	O
spatial	O
frequency	O
spectrum	O
can	O
be	O
originated	O
.	O
</s>
<s>
For	O
interference	B-Algorithm
lithography	I-Algorithm
to	O
be	O
successful	O
,	O
coherence	O
requirements	O
must	O
be	O
met	O
.	O
</s>
<s>
The	O
technique	O
is	O
readily	O
extendible	O
to	O
electron	O
waves	O
as	O
well	O
,	O
as	O
demonstrated	O
by	O
the	O
practice	O
of	O
electron	B-Algorithm
holography	I-Algorithm
.	O
</s>
<s>
Spacings	O
of	O
a	O
few	O
nanometers	O
or	O
even	O
less	O
than	O
a	O
nanometer	O
have	O
been	O
reported	O
using	O
electron	O
holograms	B-Algorithm
.	O
</s>
<s>
The	O
benefit	O
of	O
using	O
interference	B-Algorithm
lithography	I-Algorithm
is	O
the	O
quick	O
generation	O
of	O
dense	O
features	O
over	O
a	O
wide	O
area	O
without	O
loss	O
of	O
focus	O
.	O
</s>
<s>
Seamless	O
diffraction	O
gratings	O
on	O
areas	O
of	O
more	O
than	O
one	O
square	O
meter	O
have	O
been	O
originated	O
by	O
interference	B-Algorithm
lithography	I-Algorithm
.	O
</s>
<s>
nanoimprint	B-Algorithm
lithography	I-Algorithm
)	O
or	O
for	O
testing	O
photoresist	O
processes	O
for	O
lithography	O
techniques	O
based	O
on	O
new	O
wavelengths	O
(	O
e.g.	O
,	O
EUV	B-Algorithm
or	O
193	B-Algorithm
nm	I-Algorithm
immersion	I-Algorithm
)	O
.	O
</s>
<s>
Electron	O
interference	B-Algorithm
lithography	I-Algorithm
may	O
be	O
used	O
for	O
patterns	O
which	O
normally	O
take	O
too	O
long	O
for	O
conventional	O
electron	B-Architecture
beam	I-Architecture
lithography	I-Architecture
to	O
generate	O
.	O
</s>
<s>
The	O
drawback	O
of	O
interference	B-Algorithm
lithography	I-Algorithm
is	O
that	O
it	O
is	O
limited	O
to	O
patterning	O
arrayed	O
features	O
or	O
uniformly	O
distributed	O
aperiodic	O
patterns	O
only	O
.	O
</s>
<s>
Hence	O
,	O
for	O
drawing	O
arbitrarily	O
shaped	O
patterns	O
,	O
other	O
photolithography	B-Algorithm
techniques	O
are	O
required	O
.	O
</s>
<s>
In	O
addition	O
,	O
for	O
electron	O
interference	B-Algorithm
lithography	I-Algorithm
non-optical	O
effects	O
,	O
such	O
as	O
secondary	O
electrons	O
from	O
ionizing	O
radiation	O
or	O
photoacid	O
generation	O
and	O
diffusion	O
,	O
cannot	O
be	O
avoided	O
with	O
interference	B-Algorithm
lithography	I-Algorithm
.	O
</s>
