<s>
The	O
term	O
salicide	B-Algorithm
refers	O
to	O
a	O
technology	O
used	O
in	O
the	O
microelectronics	O
industry	O
used	O
to	O
form	O
electrical	O
contacts	O
between	O
the	O
semiconductor	O
device	O
and	O
the	O
supporting	O
interconnect	B-General_Concept
structure	O
.	O
</s>
<s>
The	O
salicide	B-Algorithm
process	O
involves	O
the	O
reaction	O
of	O
a	O
metal	O
thin	O
film	O
with	O
silicon	O
in	O
the	O
active	O
regions	O
of	O
the	O
device	O
,	O
ultimately	O
forming	O
a	O
metal	O
silicide	O
contact	O
through	O
a	O
series	O
of	O
annealing	O
and/or	O
etch	B-Algorithm
processes	O
.	O
</s>
<s>
The	O
term	O
"	O
salicide	B-Algorithm
"	O
is	O
a	O
compaction	O
of	O
the	O
phrase	O
self-aligned	O
silicide	O
.	O
</s>
<s>
The	O
description	O
"	O
self-aligned	O
"	O
suggests	O
that	O
the	O
contact	O
formation	O
does	O
not	O
require	O
photolithography	B-Algorithm
patterning	O
processes	O
,	O
as	O
opposed	O
to	O
a	O
non-aligned	O
technology	O
such	O
as	O
polycide	O
.	O
</s>
<s>
The	O
term	O
salicide	B-Algorithm
is	O
also	O
used	O
to	O
refer	O
to	O
the	O
metal	O
silicide	O
formed	O
by	O
the	O
contact	O
formation	O
process	O
,	O
such	O
as	O
"	O
titanium	O
salicide	B-Algorithm
"	O
,	O
although	O
this	O
usage	O
is	O
inconsistent	O
with	O
accepted	O
naming	O
conventions	O
in	O
chemistry	O
.	O
</s>
<s>
The	O
salicide	B-Algorithm
process	O
begins	O
with	O
deposition	O
of	O
a	O
thin	O
transition	O
metal	O
layer	O
over	O
fully	O
formed	O
and	O
patterned	O
semiconductor	O
devices	O
(	O
e.g.	O
</s>
<s>
transistors	B-Application
)	O
.	O
</s>
<s>
The	O
wafer	B-Architecture
is	O
heated	O
,	O
allowing	O
the	O
transition	O
metal	O
to	O
react	O
with	O
exposed	O
silicon	O
in	O
the	O
active	O
regions	O
of	O
the	O
semiconductor	O
device	O
(	O
e.g.	O
,	O
source	O
,	O
drain	O
,	O
gate	O
)	O
forming	O
a	O
low-resistance	O
transition	O
metal	O
silicide	O
.	O
</s>
<s>
The	O
transition	O
metal	O
does	O
not	O
react	O
with	O
the	O
silicon	O
dioxide	O
nor	O
the	O
silicon	O
nitride	O
insulators	O
present	O
on	O
the	O
wafer	B-Architecture
.	O
</s>
<s>
Following	O
the	O
reaction	O
,	O
any	O
remaining	O
transition	O
metal	O
is	O
removed	O
by	O
chemical	O
etching	B-Algorithm
,	O
leaving	O
silicide	O
contacts	O
in	O
only	O
the	O
active	O
regions	O
of	O
the	O
device	O
.	O
</s>
<s>
A	O
fully	O
integrable	O
manufacturing	O
process	O
may	O
be	O
more	O
complex	O
,	O
involving	O
additional	O
anneals	O
,	O
surface	O
treatments	O
,	O
or	O
etch	B-Algorithm
processes	O
.	O
</s>
<s>
Typical	O
transition	O
metals	O
used	O
or	O
considered	O
for	O
use	O
in	O
salicide	B-Algorithm
technology	O
include	O
titanium	O
,	O
cobalt	B-Algorithm
,	O
nickel	O
,	O
platinum	B-Operating_System
,	O
and	O
tungsten	B-Application
.	O
</s>
<s>
One	O
key	O
challenge	O
in	O
developing	O
a	O
salicide	B-Algorithm
process	O
is	O
controlling	O
the	O
specific	O
phase	O
(	O
compound	O
)	O
formed	O
by	O
the	O
metal-silicon	O
reaction	O
.	O
</s>
<s>
Cobalt	B-Algorithm
,	O
for	O
example	O
,	O
may	O
react	O
with	O
silicon	O
to	O
form	O
Co2Si	O
,	O
CoSi	O
,	O
CoSi2	O
,	O
and	O
other	O
compounds	O
.	O
</s>
<s>
Another	O
challenge	O
facing	O
successful	O
process	O
integration	O
include	O
lateral	O
growth	O
,	O
especially	O
underneath	O
the	O
gate	O
,	O
which	O
will	O
short	B-Application
circuit	I-Application
the	O
device	O
.	O
</s>
