<s>
Maskless	B-Algorithm
lithography	I-Algorithm
(	O
MPL	O
)	O
is	O
a	O
photomask-less	O
photolithography-like	O
technology	O
used	O
to	O
project	O
or	O
focal-spot	O
write	O
the	O
image	O
pattern	O
onto	O
a	O
chemical	O
resist-coated	O
substrate	B-Architecture
(	O
e.g.	O
</s>
<s>
wafer	B-Architecture
)	O
by	O
means	O
of	O
UV	B-Application
radiation	I-Application
or	O
electron	O
beam	O
.	O
</s>
<s>
In	O
microlithography	O
,	O
typically	O
UV	B-Application
radiation	I-Application
casts	O
an	O
image	O
of	O
a	O
time	O
constant	O
mask	O
onto	O
a	O
photosensitive	O
emulsion	O
(	O
or	O
photoresist	O
)	O
.	O
</s>
<s>
Maskless	B-Algorithm
lithography	I-Algorithm
has	O
two	O
approaches	O
to	O
project	O
a	O
pattern	O
:	O
rasterized	B-Algorithm
and	O
vectorized	O
.	O
</s>
<s>
The	O
beam	O
is	O
then	O
used	O
to	O
directly	O
write	O
the	O
image	O
into	O
the	O
photoresist	O
,	O
one	O
or	O
more	O
pixels	B-Algorithm
at	O
a	O
time	O
.	O
</s>
<s>
Also	O
combinations	O
of	O
the	O
two	O
approaches	O
are	O
known	O
,	O
and	O
it	O
is	O
not	O
limited	O
to	O
optical	O
radiation	O
,	O
but	O
also	O
extends	O
into	O
the	O
UV	O
,	O
includes	O
electron-beams	O
and	O
also	O
mechanical	O
or	O
thermal	O
ablation	O
via	O
MEMS	B-General_Concept
devices	O
.	O
</s>
<s>
A	O
key	O
advantage	O
of	O
maskless	B-Algorithm
lithography	I-Algorithm
is	O
the	O
ability	O
to	O
change	O
lithography	B-Algorithm
patterns	O
from	O
one	O
run	O
to	O
the	O
next	O
,	O
without	O
incurring	O
the	O
cost	O
of	O
generating	O
a	O
new	O
photomask	B-Algorithm
.	O
</s>
<s>
This	O
may	O
prove	O
useful	O
for	O
double	B-Algorithm
patterning	I-Algorithm
or	O
compensation	O
of	O
non-linear	O
material	O
behavior	O
(	O
e.g.	O
</s>
<s>
when	O
utilizing	O
cheaper	O
,	O
non-crystalline	O
substrate	B-Architecture
or	O
to	O
compensate	O
for	O
random	O
placement	O
errors	O
of	O
preceding	O
structures	O
)	O
.	O
</s>
<s>
The	O
main	O
disadvantages	O
are	O
complexity	O
and	O
costs	O
for	O
the	O
replication	O
process	O
,	O
the	O
limitation	O
of	O
rasterization	O
in	O
respect	O
to	O
oversampling	O
causes	O
aliasing	B-Error_Name
artefact	O
,	O
especially	O
with	O
smaller	O
structures	O
(	O
which	O
may	O
affect	O
yield	O
)	O
,	O
while	O
direct	O
vector	O
writing	O
is	O
limited	O
in	O
throughput	O
.	O
</s>
<s>
structuring	O
a	O
300mm	O
diameter	O
wafer	B-Architecture
with	O
its	O
area	O
of	O
~	O
707cm²	O
requires	O
about	O
10	O
TiB	O
of	O
data	O
in	O
a	O
rasterized	B-Algorithm
format	O
without	O
oversampling	O
and	O
thus	O
suffers	O
from	O
step-artefacts	O
(	O
aliasing	B-Error_Name
)	O
.	O
</s>
<s>
Oversampling	O
by	O
a	O
factor	O
of	O
10	O
to	O
reduce	O
these	O
artefacts	O
adds	O
another	O
two	O
orders	O
of	O
magnitude	O
1	O
PiB	O
per	O
single	O
wafer	B-Architecture
that	O
has	O
to	O
be	O
transferred	O
in	O
~	O
1	O
min	O
to	O
the	O
substrate	B-Architecture
to	O
achieve	O
high	O
volume	O
manufacturing	O
speeds	O
.	O
</s>
<s>
Industrial	O
maskless	B-Algorithm
lithography	I-Algorithm
is	O
therefore	O
currently	O
only	O
widely	O
found	O
for	O
structuring	O
lower	O
resolution	O
substrates	B-Architecture
,	O
like	O
in	O
PCB-panel	O
production	O
,	O
where	O
resolutions	O
~	O
50µm	O
are	O
most	O
common	O
(	O
at	O
~	O
2000	O
times	O
lower	O
throughput	O
demand	O
on	O
the	O
components	O
)	O
.	O
</s>
<s>
Currently	O
,	O
the	O
main	O
forms	O
of	O
maskless	B-Algorithm
lithography	I-Algorithm
are	O
electron	O
beam	O
and	O
optical	O
.	O
</s>
<s>
The	O
most	O
commonly	O
used	O
form	O
of	O
maskless	B-Algorithm
lithography	I-Algorithm
today	O
is	O
electron	B-Architecture
beam	I-Architecture
lithography	I-Architecture
.	O
</s>
<s>
This	O
is	O
already	O
being	O
used	O
in	O
wafer-level	O
production	O
at	O
eASIC	O
,	O
which	O
uses	O
conventional	O
direct-write	O
electron	B-Architecture
beam	I-Architecture
lithography	I-Architecture
to	O
customize	O
a	O
single	O
via	O
layer	O
for	O
low-cost	O
production	O
of	O
ASICs	O
.	O
</s>
<s>
Most	O
maskless	B-Algorithm
lithography	I-Algorithm
systems	O
currently	O
being	O
developed	O
are	O
based	O
on	O
the	O
use	O
of	O
multiple	O
electron	O
beams	O
.	O
</s>
<s>
Direct	O
laser	O
writing	O
is	O
a	O
very	O
popular	O
form	O
of	O
optical	O
maskless	B-Algorithm
lithography	I-Algorithm
,	O
which	O
offers	O
flexibility	O
,	O
ease	O
of	O
use	O
,	O
and	O
cost	O
effectiveness	O
in	O
R&D	O
processing	O
(	O
small	O
batch	O
production	O
)	O
.	O
</s>
<s>
The	O
underlying	O
technology	O
uses	O
spatial	O
light	O
modulating	O
(	O
SLM	O
)	O
micro-arrays	O
based	O
on	O
glass	O
to	O
block	O
laser	O
pathway	O
from	O
reaching	O
a	O
substrate	B-Architecture
with	O
a	O
photoresist	O
(	O
in	O
similar	O
manner	O
to	O
digital	B-General_Concept
micromirror	I-General_Concept
devices	I-General_Concept
)	O
.	O
</s>
<s>
The	O
MCC	O
system	O
also	O
included	O
circuit	O
editing	O
capabilities	O
for	O
isolating	O
circuits	O
on	O
a	O
programmable	O
wafer	B-Architecture
design	O
.	O
</s>
<s>
In	O
1999	O
,	O
the	O
MCC	O
system	O
was	O
advanced	O
for	O
use	O
in	O
MEMS	B-General_Concept
manufacturing	O
.	O
</s>
<s>
Interference	B-Algorithm
lithography	I-Algorithm
or	O
holographic	O
exposures	O
are	O
not	O
maskless	O
processes	O
and	O
therefore	O
do	O
not	O
count	O
as	O
"	O
maskless	O
"	O
,	O
although	O
they	O
have	O
no	O
1:1	O
imaging	O
system	O
in	O
between	O
.	O
</s>
<s>
Plasmonic	B-Algorithm
direct	I-Algorithm
writing	I-Algorithm
lithography	I-Algorithm
uses	O
localized	O
surface	O
plasmon	O
excitations	O
via	O
scanning	O
probes	O
to	O
directly	O
expose	O
the	O
photoresist	O
.	O
</s>
<s>
For	O
improved	O
image	O
resolution	O
,	O
ultraviolet	B-Application
light	O
,	O
which	O
has	O
a	O
shorter	O
wavelength	O
than	O
visible	O
light	O
,	O
is	O
used	O
to	O
achieve	O
resolution	O
down	O
to	O
around	O
100nm	O
.	O
</s>
<s>
The	O
main	O
optical	O
maskless	B-Algorithm
lithography	I-Algorithm
systems	O
in	O
use	O
today	O
are	O
the	O
ones	O
developed	O
for	O
generating	O
photomasks	B-Algorithm
for	O
the	O
semiconductor	O
and	O
LCD	B-Device
industries	O
.	O
</s>
<s>
DLP	B-General_Concept
technology	O
can	O
also	O
be	O
used	O
for	O
maskless	B-Algorithm
lithography	I-Algorithm
.	O
</s>
<s>
IBM	O
Research	O
has	O
developed	O
an	O
alternative	O
maskless	B-Algorithm
lithography	I-Algorithm
technique	O
based	O
on	O
atomic	O
force	O
microscopy	O
.	O
</s>
<s>
Technologies	O
that	O
enable	O
maskless	B-Algorithm
lithography	I-Algorithm
is	O
already	O
used	O
for	O
the	O
production	O
of	O
photomasks	B-Algorithm
and	O
in	O
limited	O
wafer-level	O
production	O
.	O
</s>
<s>
Even	O
within	O
the	O
electron-beam	O
category	O
,	O
there	O
are	O
several	O
vendors	O
(	O
Multibeam	O
,	O
Mapper	O
Lithography	B-Algorithm
,	O
Canon	O
,	O
Advantest	O
,	O
Nuflare	O
,	O
JEOL	O
)	O
with	O
entirely	O
different	O
architectures	O
and	O
beam	O
energies	O
.	O
</s>
<s>
Second	O
,	O
throughput	O
targets	O
exceeding	O
10	O
wafers	B-Architecture
per	O
hour	O
still	O
need	O
to	O
be	O
met	O
.	O
</s>
<s>
In	O
recent	O
years	O
DARPA	O
and	O
NIST	O
have	O
reduced	O
support	O
for	O
maskless	B-Algorithm
lithography	I-Algorithm
in	O
the	O
U.S.	O
</s>
<s>
There	O
was	O
a	O
European	O
program	O
that	O
would	O
push	O
the	O
insertion	O
of	O
maskless	B-Algorithm
lithography	I-Algorithm
for	O
IC	O
manufacturing	O
at	O
the	O
32-nm	O
half-pitch	O
node	O
in	O
2009	O
.	O
</s>
<s>
Project	O
name	O
was	O
MAGIC	O
,	O
or	O
"	O
MAskless	B-Algorithm
lithoGraphy	I-Algorithm
for	O
IC	O
manufacturing	O
"	O
,	O
in	O
frame	O
of	O
EC	O
7th	O
Framework	O
Programme	O
(	O
FP7	O
)	O
.	O
</s>
<s>
Due	O
to	O
the	O
increased	O
mask	O
costs	O
for	O
multiple	B-Algorithm
patterning	I-Algorithm
,	O
maskless	B-Algorithm
lithography	I-Algorithm
is	O
once	O
again	O
prompts	O
relevant	O
research	O
in	O
this	O
field	O
.	O
</s>
<s>
Since	O
at	O
least	O
2001	O
DARPA	O
has	O
invested	O
in	O
a	O
variety	O
of	O
maskless	O
patterning	O
technologies	O
including	O
parallel	O
e-beam	O
arrays	O
,	O
parallel	O
scanning	O
probe	O
arrays	O
,	O
and	O
an	O
innovative	O
e-beam	B-Architecture
lithography	I-Architecture
tool	O
to	O
enable	O
low-volume	O
manufacturing	O
process	O
.	O
</s>
<s>
In	O
2018	O
the	O
Dutch	O
and	O
Russia	O
jointly	O
funded	O
(	O
Rusnano	O
)	O
company	O
Mapper	O
Lithography	B-Algorithm
producing	O
multi	O
e-beam	O
maskless	B-Algorithm
lithography	I-Algorithm
MEMS	B-General_Concept
components	O
went	O
bankrupt	O
and	O
was	O
acquired	O
by	O
ASML	O
Holding	O
,	O
a	O
major	O
competitor	O
at	O
the	O
time	O
.	O
</s>
<s>
The	O
Mapper	O
Lithography	B-Algorithm
originally	O
was	O
created	O
at	O
Delft	O
University	O
of	O
Technology	O
in	O
2000	O
.	O
</s>
