huazhi li harvard university, 12 oxford street, cambridge...
TRANSCRIPT
ALD and CVD Ni using Ni Amidinate Precursor
Huazhi Li1, Deo V. Shenai1, Zhefeng Li2 and Roy G. Gordon2
1. Rohm and Haas Electronic Materials LLC, Microelectronic Technologies,60 Willow Street, North Andover, MA 01845, U.S.A. 2. Department of Chemistry and Chemical Biology,Harvard University, 12 Oxford Street, Cambridge, MA 02138, U.S.A.
Nickel silicide (NiSi) is emerging as the choice material for contact applications in
semiconductor device processing for the 65nm technology node and beyond. As
the dimensions of microelectronic circuits are being reduced, the non-conformal
nature of sputtered Ni contact layers has started to cause problems. Chemical
vapor deposition (CVD) and atomic layer deposition (ALD) are identified as the
methods that can produce thin conformal contact layers (<10 nm). In this
presentation we demonstrate the effectiveness of novel nickel amidinate (Ni AMD)
as a good precursor in both ALD and CVD Ni thin films due to its high thermal
stability and high reactivity. Ni AMD has acceptable vapor pressure (> 0.1 Torr at
90 ºC) for both ALD and CVD applications. Its solubility in common commercial
solvents is excellent, which allows it to be used in direct liquid injection (DLI)
mode. Our results confirm that when this precursor reacts with ammonia as
second reagent in ALD, it readily forms Ni3N films. These NiNx films can be
converted to conductive NiSi films with annealing under reducing environment
such as using hydrogen. The conformality of both ALD and CVD films was
confirmed inside holes with 40: aspect ratio.
ALD
dC
VDfN
iNU
iA
LD a
ndC
VD o
fNiN
Usi
ngN
icke
l Am
idin
ate
Sour
ce
Huaz
hi L
i and
Deo
She
nai
Dow
Ele
ctro
nic
Mat
eria
ls,
The
Dow
Che
mic
al C
ompa
ny, N
orth
A
ndov
er, M
A 0
1845
Zhef
eng
Li an
d Ro
y G
ordo
nDe
pt o
f Che
mist
ry a
nd C
hem
ical
Bio
logy
, H
dU
iit
Cb
idM
A02
138
Harv
ard
Univ
ersit
y, C
ambr
idge
, MA
021
38
July
19,
200
920
09D
Elt
iM
ti
l20
09D
owEl
ectr
onic
Mat
eria
ls
Bac
kgro
und
and
Mot
ivat
ion
for A
LD/C
VD N
iSi
Met
al g
ate
Sour
ceD
rain
Cha
nnel
Hig
h k
oxid
e
•NiS
i is
wid
ely
used
in C
MO
S fo
r sou
rce
and
drai
n co
ntac
t met
al.
•NiS
i offe
rs th
e ad
vant
age
of s
ubst
antia
lly lo
w re
sist
ance
than
oth
er m
etal
s.
•With
the
com
plex
ity o
f str
uctu
res
invo
lved
at 3
2 nm
and
bey
ond,
•
ALD
is c
onsi
dere
d as
pre
ferr
ed te
chni
que
than
CVD
for N
iSi
•G
ood
prec
urso
rs o
f acc
epta
ble
stab
ility
and
reac
tivity
are
nee
ded
•B
ette
rpre
curs
ors
need
edfo
rdep
ositi
ons
bybo
thA
LDan
dC
VDB
ette
rpre
curs
ors
need
edfo
rdep
ositi
ons
bybo
thA
LDan
dC
VD•M
ost o
f the
com
mer
cial
Ni p
recu
rsor
s ha
ve li
mite
d st
abili
ty a
nd re
activ
ity
•e.
g. N
i(PF 3
) 4, N
i(CO
) 4an
d N
i(aca
c)2.
•New
ALD
/CVD
resu
lts u
sing
NiA
MD
pre
curs
or a
re p
rese
nted
in th
is w
ork
Ni A
mid
ina
te
Pr
ec
ur
so
r f
or
AL
D
an
d C
VD
1000
0.00
TGA
of N
i-AM
DVa
por P
ress
ure
Cur
ve fo
r Ni-A
MD
1000
.00
ssure (mtorr)
100.0
0
Vapor Pres
10.00
5060
7080
9010
011
012
013
0Te
mper
ature
Cen
tigra
de
•Lo
w m
eltin
g po
int s
olid
(87
ºC) w
ith g
ood
shel
f life
and
ther
mal
sta
bilit
y•
Hig
h va
por p
ress
ure
(>1
Torr
@ 9
0 ºC
) offe
rs a
dvan
tage
of h
igh
thro
ughp
ut•
Ne g
ligib
le e
vapo
ratio
n re
sidu
e as
con
firm
ed b
y TG
Ag
gp
y
Ther
mal
Sta
bilit
y of
Ni A
MD
by
AR
C
ARC
Resu
lts: N
ickle
amidi
nate
[Ni_a
md.da
t]
Acc
eler
atin
g R
ate
Cal
orim
etry
(AR
C) S
tudi
es o
n N
i-AM
D
250
300
350
ees C)
200
250
Onse
t Tem
p. (d
eg C
):22
0.24
48
100
150
200
le Temp. (Degre
100
150
Pressure (psia)
050100
020
040
060
080
010
0012
0014
0016
0018
00
Samp
050
000
0060
080
000
000
0060
080
0
Time (
Minu
tes)
•Ons
et o
f the
rmal
dec
ompo
sitio
n is
repo
rted
at a
roun
d 22
0 º C
•Hal
f life
(t1/
2) a
t 130
ºC w
as fo
und
to b
e 96
hrs
by
NM
R s
tudi
es
AL
D a
nd
CV
D N
i Co
nd
itio
ns
ALD
/CV
Dco
nditi
ons
Bub
bler
tem
pera
ture
for A
LD/C
VD: 9
0-10
0 C
(mol
ten
sour
ce)
ALD
/CVD
subs
trat
ete
mpe
ratu
re:2
75C
.
/Cco
dto
s
ALD
/CVD
subs
trat
ete
mpe
ratu
re:2
75C
.In
ALD
mod
e, th
e se
cond
reac
tant
is N
H3.
In C
VD m
ode,
the
seco
nd re
acta
nt is
H2/N
H3.
Silic
idat
ion
carr
ied
ot
sing
rapi
dth
erm
alan
neal
ing
(RTA
)Si
licid
atio
nca
rrie
dou
t usi
ngra
pid
ther
mal
anne
alin
g(R
TA):
at 5
50 ºC
, usi
ng fo
rmin
g ga
s at
5 T
orr f
or 5
min
.
Phy
sica
lpro
perti
es o
f Ni-A
MD
Nam
eN
icke
l Bis
(N,N
’-dite
rtial
buty
lace
tam
idin
ate)
XP n
umbe
rXP
-072
39
Form
ula
BD
TBA
Ni,
Ni(t
Bu 2
-am
d)2,
((tB
u)N
C(C
H3)
N(tB
u)2N
i
yp
p
((tB
u)N
C(C
H3)
N(tB
u)2N
i
Mol
ecul
ar W
eigh
t39
7.27
App
eara
nce
brow
n so
lid
m.p
. (ºC
)87
o C
Den
sit
(g/m
l)0
65D
ensi
ty(g
/ml)
0.65
Ther
mal
Sta
bilit
ygr
eate
r tha
n 2
mon
ths
at 9
0 o C
She
lf lif
eM
ore
than
12
mon
th
ALD
of N
iN0.
1on
Sia
nd S
iO2
160
200
onSi
SiO
80120
160
Thickness (A)
onSi
onSi
O2
040
020
040
060
080
010
00
T
ALD
rate
;~
0.2
Å/c
ycle
# of
cyc
les
ALD
rate
;~
0.6
Å/c
ycle
(bef
ore
60 c
ycle
s)0
2Å
/cyc
le(a
fter6
0cy
cles
)y
~0.
2Å
/cyc
le(a
fter6
0cy
cles
)
Hig
her g
row
th ra
te is
ach
ieve
d in
itial
ly o
n Si
O2
subs
trat
eth
an o
n Si
.A
fter~
60cy
cles
com
para
ble
grow
thra
tes
are
achi
eved
onSi
and
SiO
Afte
r~60
cycl
es,c
ompa
rabl
egr
owth
rate
sar
eac
hiev
edon
Sian
dSi
O2.
XRD
of A
LD N
iN0.
1on
Si
Si (111)
i (220)
(121)
310)
NiS
NiSi
NiSi(
NiSi (3
)
Post
Ann
eal,
NiS
i
Ni (101)
As
Dep
osite
d, N
i
Nitr
ogen
exp
elle
d an
d pu
re N
iSi f
orm
edSh
eet R
esist
ance
of N
iSi a
fter a
nnea
ling
~4.2
/sq
Resis
tivity
of N
iSi ~
32-c
m (l
owes
t rep
orte
d va
lue
~14
-cm
)
Dep
ositi
on R
ate
of C
VD N
iNx
Film
s
Slop
e =>
5 n
anom
eter
s pe
r min
ute
Inte
rcep
t~0
=>no
nucl
eatio
nde
lay
Inte
rcep
t~0
=>no
nucl
eatio
nde
lay
Com
posi
tion
of C
VD N
iNx
Film
s by
RB
S
Ni 3.
2N
Ni 11
7N
Ni
11.7
Hfl
60N
Hfl
Nflo
=60
sccm
Ni
H2
flow
= 6
0 –
NH
3flo
wN
2flo
w=
60sc
cm
Co
mp
le
te
St
ep
Co
ve
ra
ge
(>5
0:1
ho
le
s)
by
CV
D
CV
D N
iSi D
ep
th
Pr
of
ile
by
X
PS
Si2p
Ni2p
3/2
C1s
O1s
N1s
405s
585s
135s
225s
405s
Asde
p
15s
45s
1000
800
600
400
200
0B
indi
ng E
nerg
y (e
V)
Asde
p
•XPS
con
firm
s hi
gh p
urity
NiS
i film
s w
ith n
o C
, N o
r O im
purit
ies
Sum
mar
y
Ni-A
MD
has
suf
ficie
nt v
apor
pre
ssur
e, g
ood
ther
mal
sta
bilit
y, a
nd
exce
llent
reac
tivity
for A
LD a
nd C
VD
app
licat
ions
.
ALD
and
CV
D u
sing
NH
3le
ad to
Ni r
ich
NiN
xon
Si,
whi
ch c
an b
e co
nver
ted
to p
ure
NiS
i afte
r ann
ealin
g un
der N
2.
Com
plet
e st
ep-c
over
age
is a
chie
ved
in C
VD
NiN
xw
ith 5
0:1
aspe
ct
ratio
hol
es a
t sig
nific
antly
hig
her g
row
th ra
tes
than
in A
LD m
ode.
Hig
h pu
rity
of N
iSi f
ilms,
as
dem
onst
rate
d by
XP
S, c
onfir
m N
I-AM
D
to b
e a
bette
r sou
rce
for A
LD a
nd C
VD
of N
i-com
pris
ing
film
s