Precursors with Metal-Nitrogen Bonds for ALD of Metals, Nitrides and Oxides · 2014-12-03 ·...
Transcript of Precursors with Metal-Nitrogen Bonds for ALD of Metals, Nitrides and Oxides · 2014-12-03 ·...
Precursors with Metal-Nitrogen Bonds for ALD of Metals, Nitrides and Oxides
Roy Gordon [email protected]
Harvard University, Cambridge, MA
Abstract
To achieve ALD’s unique characteristics, ALD precursors must have very specific properties: high and self-limited reactivity with surfaces, high thermal stability and adequate volatility. In addition, their reaction byproducts must not react with the deposited films or the substrates. Precursors with metal-nitrogen bonds have been found to be particularly effective for ALD of metal oxides, nitrides and pure metals: dialkylamides of Al, Sn, Ti, Zr, Hf, Nb and Ta; dialkylamide-alkylimide mixed ligand compounds of Nb, Ta, Mo and W; dialkylacetamidinates of Mg, Ca, Sc, Ti, V, Cr, Mn, Fe, Ru, Co, Rh, Ni, Cu, Bi, Y, La and the other lanthanide metals. As one example, new precursors for ALD of nickel will be presented. Other examples of the materials made from these precursors include high-k dielectric insulators HfO2, HfON, HfSiON and LaAlO3; electrical conductors of Cu; conducting Cu diffusion barriers of WN and TaNx;metals Co and Ru that promote strong adhesion between Cu and nitride diffusion barriers; magnetic metals Fe, Co and Ni and their magnetoresistive combinations with Al2O3 or MgO; photonic crystals of high-dielectric constant material Ta3N5; insulating AlN and Hf3N4 for passivating Ge surfaces.
Har
vard
Uni
vers
ity
Roy
G. G
ordo
nHa
rvar
d Un
iver
sity
Cam
brid
ge, M
A
Har
vard
Uni
vers
ity
How
man
y pr
ecur
sors
are
nee
ded?
Che
mic
al T
ypes
of P
recu
rsor
s fo
r ALD
Prec
urso
rs w
ith M
etal
-Nitr
ogen
Bon
ds
Met
als:
Ni,
Cu
Nitr
ides
: Hf 3
N4
=> H
fN
Oxi
des:
Lan
than
ides
, Tra
nsiti
on m
etal
s
Out
line
Har
vard
Uni
vers
ity
How
Man
y Pr
ecur
sors
Nee
ded
for A
LD?
Har
vard
Uni
vers
ity
Num
ber o
f Ele
men
ts in
a C
ompu
ter C
hip
Har
vard
Uni
vers
ity
•Suf
ficie
nt v
olat
ility
(> 0
.1 T
orr)
•Suf
ficie
nt th
erm
al s
tabi
lity
•Hig
h, s
elf-l
imite
d re
activ
ity w
ith s
ubst
rate
s
•Hig
h, s
elf-l
imite
d re
activ
ity w
ith th
e su
rfac
e pr
epar
ed b
y th
e ot
her p
recu
rsor
•Pre
curs
ors
and
bypr
oduc
ts th
at d
on’t
etch
or
adso
rb o
n th
e fil
m o
r the
sub
stra
te
Crit
eria
for A
LD P
recu
rsor
s
Har
vard
Uni
vers
ity
Type
s of
Pre
curs
ors
for A
LD M
N
R
Alky
limid
es
Har
vard
Uni
vers
ity
Lim
itatio
ns o
f Pre
curs
or T
ypes
for A
LD
Har
vard
Uni
vers
ity
Rea
ctiv
ity o
f Haf
nium
Pre
curs
ors
Hf(N
Me 2
) 4ha
s hi
ghes
t rea
ctiv
ity w
ith w
ater
and
am
mon
ia,
lead
ing
to th
e•P
ures
t film
s (<
0.1%
impu
ritie
s)•S
moo
thes
t film
s (r
ough
ness
sam
e as
sub
stra
te)
•Hig
hest
ste
p co
vera
ge (>
200:
1 as
pect
ratio
s)•L
owes
t dep
ositi
on te
mpe
ratu
re (~
50 o C
)
Hf
NM
e 2M
e 2N
NM
e 2
NM
e 2
Hf
Cl
Cl
Cl
Cl
Hf
OBu
tBu
t O
OBu
t
OBu
t
>>
Haf
nium
dim
ethy
lam
ide
Haf
nium
chl
orid
eH
afni
um te
rt-bu
toxi
de
Har
vard
Uni
vers
ity
Prec
urso
rs w
ith N
itrog
en-B
ased
Lig
ands
HH
eL
i B
e B
C
N
O
F N
e N
a M
g A
l Si
P
S C
l A
r K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
Rb
Sr
Y
Zr
Nb
Mo
Tc
Ru
Rh
PdA
g C
d In
Sn
Sb
T
e I
Xe
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
Fr
Ra
Ac
C
e Pr
N
d Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Y
b L
u
Th
Pa
U
Np
Pu
Am
C
m
Bk
Cf
Es
Fm
Md
No
Lr
Gre
en =
at l
east
one
vol
atile
N-b
ased
pre
curs
or k
now
n
Har
vard
Uni
vers
ity
ALD
of t
rans
ition
met
als
from
am
idin
ate
prec
urso
rs
1 Zhe
ngw
en L
i, A
LD 2
005,
Tue
sday
1:4
5
2 Hua
zhi L
i, A
LD 2
005,
Tue
sday
2:1
5
Har
vard
Uni
vers
ity
Stru
ctur
es o
f 2 N
i ace
tam
idin
ate
prec
urso
rs
Har
vard
Uni
vers
ity
Har
vard
Uni
vers
ity
Nic
kel P
recu
rsor
s w
ith V
ario
us A
lkyl
Gro
ups
100 80 60 40 20
5010
015
020
025
030
035
040
0
R
R
esid
ue(%
)M
e
0.
7E
t
0.
5i P
r0.
8P
h
3.
6
Weight (%)
Tem
pera
ture
(°C
)
t Bu N t BuN
R
t BuNt Bu N
RN
i
0
Har
vard
Uni
vers
ityALD
of N
icke
l on
Si
95 ºC
sou
rce
(liqu
id)
270º
C s
ubst
rate
Gro
wth
: ~0
.2 Å
/cyc
le
with
eith
er H
2or
NH
3
RB
S sp
ectr
um (7
00 c
ycle
s)
Thic
knes
s ~
14 n
m
050100
150
020
040
060
080
0#
of c
ycle
s
Thickness (A)
020
040
060
080
010
00C
hann
el
05101520253035 NormalizedYield
0.5
1.0
1.5
Ener
gy(M
eV)
Har
vard
Uni
vers
ity
XR
D o
f Nic
kel o
n S
i10
0 80 60 40 20 0
50
4540
3530
2 th
eta
( de
gree
s )
NiSi(111)
NiSi(220)
NiSi(121)
NiSi(310)
Ni (101)
Ann
eale
d, N
iSi
As
Dep
osite
d, N
i
Sili
cida
tion
usin
g R
TA :
550
ºC, 5
min
in fo
rmin
g ga
s (lo
w p
ress
ure)
She
et re
sist
ance
of N
i as
depo
site
d ~
90
/�, 1
4 nm
She
et R
esis
tanc
e of
NiS
iafte
r ann
ealin
g ~
4.2
/�
Har
vard
Uni
vers
ity
ALD
of N
icke
l on
SiO
2
Dep
ositi
on C
ondi
tions
: 270
ºC/ 9
5 ºC
Gro
wth
bef
ore
60 c
ycle
s ~
0.6
Å/ c
ycle
Gro
wth
afte
r 60
cycl
es ~
0.2
Å/c
ycle
Res
istiv
ity~
68
-cm
( 90
0 cy
cle,
18
nm,
She
et R
esis
tanc
e ~
38
/�)
RB
S s
pect
rum
for 7
00
cycl
es
Thic
knes
s ~
14 n
m
200
300
400
500
600
700
800
Cha
nnel
051015202530 NormalizedYield
0.4
0.6
0.8
1.0
1.2
1.4
Ener
gy(M
eV)
020406080100
120
140
160
180
200
020
040
060
080
010
00
# of
cyc
les
Thickness (A)
Har
vard
Uni
vers
ity
TEM
of N
ucle
atio
n of
Nic
kel o
n S
iO2
Gro
wth
at 2
70 ºC
, 30
cyc
les
Thic
knes
s by
RB
S ~
1.7
nm
Ave
rage
gra
in d
iam
eter
5-1
0 nm
Har
vard
Uni
vers
ity
Prec
urso
rs fo
r ALD
of C
oppe
r Film
sC
u(I)
N,N
’-di-s
ec-b
utyl
acet
amid
inat
e[C
u(se
c-Bu
2-am
d)] 2
Mel
ting
poin
t: 77
o CVa
por p
ress
ure
of li
quid
: 95
o C/0
.2 T
orr
Rea
ctiv
e to
mol
ecul
ar h
ydro
gen,
H2
0.1
to 2
Ang
stro
m p
er c
ycle
Zhen
gwen
Li, A
LD 2
005
(Tue
sday
, 1:4
5pm
)
1 -2
SiO
2, A
l 2O3,
HfO
2
0.1
-0.2
Ru
0.4
-0.5
Co
0.4
-0.5
Cu
Gro
wth
(A/c
ycle
)Su
bstr
ate
Har
vard
Uni
vers
ity
TEM
Stu
dy o
f Cu
Nuc
leat
ion
on S
iO2
and
on C
o
2 nm
Cu,
man
y sm
all n
ucle
iel
ectr
ical
ly c
onne
cted
50 A
LD c
ycle
s of
Cu/
H2
on a
Co/
SiO
2su
bstr
ate:
30 A
LD c
ycle
s of
Cu/
H2
on a
SiO
2su
bstr
ate
:
6 nm
Cu,
few
larg
e nu
clei
not e
lect
rical
ly c
onne
cted
40/�
for 4
nm
thic
k C
u se
ed la
yer
Har
vard
Uni
vers
ity
ALD
of m
etal
nitr
ides
from
nitr
ogen
-bas
ed li
gand
s
1 Zhe
ngw
en L
i, A
LD 2
005
(Tue
sday
1:4
5pm
)
Har
vard
Uni
vers
ity
ALD
of H
afni
um N
itrid
es, H
f 3N
4an
d H
fN
Jill
S.B
ecke
r, E
sthe
r K
im a
nd R
oy G
.Gor
don
Chem
. Mat
er.(
2004
), 16
, 349
7.
Top
Botto
m
60 n
m
60 n
m
Top
Botto
m
60 n
m
60 n
m
Top
Botto
m
60 n
m
60 n
m
Har
vard
Uni
vers
ity
Con
vers
ion
of In
sula
ting
Hf3N
4to
Met
allic
HfN
2030
4050
60050100
150
Si
As d
epos
ited
900
o C
1050
o C
HfN (220)
HfN (200)
HfN ( 111)
CPS
2
Har
vard
Uni
vers
ity
New
Lan
than
ide
Prec
urso
rs
Mos
t vol
atile
La
com
poun
d kn
own
(~0.
1 To
rr/1
30 o C
)H
igh
ther
mal
sta
bilit
y (~
300
o Cin
ALD
reac
tor)
Initi
ates
gro
wth
on
HF-
last
sili
con,
EO
T ~
1nm
, < m
Ale
akag
e
R =
isop
ropy
l
La
NN
NN
NN
CC
CR
R
RR
RR
CH
3
CH
3H
3C
Har
vard
Uni
vers
ityTG o
f Yttr
ium
Am
idin
ates
Har
vard
Uni
vers
ity
Mod
els
for Y
ttriu
m A
mid
inat
es
Har
vard
Uni
vers
ity
ALD
of m
etal
(III)
oxid
es fr
om a
mid
inat
epr
ecur
sors
*Phi
lippe
de
Rou
ffig
nac,
ALD
200
5 (W
edne
sday
B 8
:45
am)
# Kyo
ung
Kyo
ung --
hahaK
im, A
LD 2
005
(Wed
nesd
ay B
8:1
5 am
)
Har
vard
Uni
vers
ity
Mod
els
for L
anth
anum
and
Sca
ndiu
m A
mid
inat
es
Har
vard
Uni
vers
ity
Har
vard
Uni
vers
ity
ALD
of m
etal
(II) o
xide
s fro
m a
mid
inat
es
Har
vard
Uni
vers
ity
Har
vard
Uni
vers
ityAck
now
ledg
emen
ts