<s>
Plasmonic	B-Algorithm
nanolithography	I-Algorithm
(	O
also	O
known	O
as	O
plasmonic	B-Algorithm
lithography	I-Algorithm
or	O
plasmonic	O
photolithography	B-Algorithm
)	O
is	O
a	O
nanolithographic	B-Algorithm
process	I-Algorithm
that	O
utilizes	O
surface	O
plasmon	O
excitations	O
such	O
as	O
surface	O
plasmon	O
polaritons	O
(	O
SPPs	O
)	O
to	O
fabricate	O
nanoscale	O
structures	O
.	O
</s>
<s>
SPPs	O
,	O
which	O
are	O
surface	O
waves	O
that	O
propagate	O
in	O
between	O
planar	O
dielectric-metal	O
layers	O
in	O
the	O
optical	O
regime	O
,	O
can	O
bypass	O
the	O
diffraction	O
limit	O
on	O
the	O
optical	O
resolution	O
that	O
acts	O
as	O
a	O
bottleneck	O
for	O
conventional	O
photolithography	B-Algorithm
.	O
</s>
<s>
They	O
originate	O
from	O
coupling	O
of	O
photons	B-Application
to	O
plasma	O
oscillations	O
,	O
quantized	O
as	O
plasmons	O
.	O
</s>
<s>
Nevertheless	O
,	O
the	O
excitation	O
of	O
SPPs	O
necessitate	O
momentum	O
mismatch	O
;	O
prism	O
and	O
grating	B-Device
coupling	O
methods	O
are	O
common	O
.	O
</s>
<s>
For	O
plasmonic	B-Algorithm
nanolithography	I-Algorithm
processes	O
,	O
this	O
is	O
achieved	O
through	O
surface	O
roughness	O
and	O
perforations	O
.	O
</s>
<s>
Plasmonic	O
contact	O
lithography	O
,	O
a	O
modification	O
on	O
the	O
evanescent	O
near-field	O
lithography	O
,	O
uses	O
a	O
metal	O
photomask	B-Algorithm
,	O
on	O
which	O
the	O
SPPs	O
are	O
excited	O
.	O
</s>
<s>
Similar	O
to	O
common	O
photolithographic	B-Algorithm
processes	O
,	O
photoresist	O
is	O
exposed	O
to	O
SPPs	O
that	O
propagate	O
from	O
the	O
mask	O
.	O
</s>
<s>
Photomasks	B-Algorithm
with	O
holes	O
enable	O
grating	B-Device
coupling	O
of	O
SPPs	O
;	O
the	O
fields	O
only	O
propagate	O
for	O
nanometers	O
.	O
</s>
<s>
Zayats	O
and	O
Smolyaninov	O
utilized	O
a	O
multi-layered	O
metal	O
film	O
mask	O
to	O
enhance	O
the	O
subwavelength	O
aperture	B-General_Concept
;	O
such	O
structures	O
can	O
be	O
realized	O
by	O
thin	O
film	O
deposition	O
methods	O
.	O
</s>
<s>
Bowtie	O
apertures	B-General_Concept
and	O
nanogaps	O
were	O
also	O
suggested	O
as	O
alternative	O
apertures	B-General_Concept
.	O
</s>
<s>
A	O
version	O
of	O
the	O
method	O
,	O
named	O
as	O
surface	O
plasmon	O
interference	O
nanolithography	B-Algorithm
by	O
Liu	O
et	O
al.	O
,	O
uses	O
SPP	O
interference	O
patterns	O
.	O
</s>
<s>
Planar	O
lens	O
imaging	O
nanolithography	B-Algorithm
uses	O
plasmonic	O
lenses	O
or	O
negative-index	O
superlenses	O
,	O
which	O
were	O
first	O
proposed	O
by	O
John	O
Pendry	O
.	O
</s>
<s>
has	O
demonstrated	O
the	O
imaging	O
of	O
a	O
30	O
nm	O
chromium	B-Language
grating	B-Device
through	O
silver	O
superlens	O
photolithography	B-Algorithm
at	O
380	O
nm	O
,	O
while	O
Shi	O
et	O
al	O
.	O
</s>
<s>
has	O
developed	O
a	O
mechanically	O
adjustable	O
,	O
hovering	O
plasmonic	O
lens	O
for	O
maskless	B-Algorithm
near-field	O
nanolithography	B-Algorithm
,	O
whereas	O
another	O
maskless	B-Algorithm
approach	O
by	O
Pan	O
et	O
al	O
.	O
</s>
<s>
Plasmonic	O
direct	O
writing	O
is	O
a	O
maskless	B-Algorithm
form	O
of	O
photolithography	B-Algorithm
that	O
is	O
based	O
on	O
scanning	O
probe	O
lithography	O
;	O
the	O
method	O
uses	O
localized	O
surface	O
plasmon	O
(	O
LSP	O
)	O
enhancements	O
from	O
embedded	O
plasmonic	O
scanning	O
probes	O
to	O
expose	O
the	O
photoresist	O
.	O
</s>
<s>
Gold	O
nanoparticles	O
and	O
other	O
plasmonic	O
nanostructures	O
such	O
as	O
nanogaps	O
have	O
been	O
used	O
as	O
masks	O
for	O
lithography	O
;	O
etching	O
in	O
this	O
case	O
can	O
be	O
achieved	O
through	O
either	O
through	O
photomasking	B-Algorithm
principles	O
or	O
enhanced	O
local	O
heating	O
in	O
the	O
vicinity	O
of	O
the	O
nanostructure	O
due	O
to	O
the	O
LSP	O
resonances	O
.	O
</s>
<s>
also	O
used	O
localized	O
thermal	O
excitations	O
in	O
gold	O
nanoparticles	O
to	O
fabricate	O
two-dimensional	O
structures	O
such	O
as	O
patterned	O
graphene	O
and	O
molybdenum	O
disulfide	O
monolayers	O
in	O
a	O
process	O
termed	O
as	O
"	O
optothermoplasmonic	O
nanolithography.	O
"	O
</s>
