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Overview of ALD Precursors and Reaction Mechanisms Roy G. Gordon
Department of Chemistry and Chemical Biology,
Harvard University, Cambridge, MA 02138, U.S.A.
Abstract
Successful use of ALD requires suitable chemical precursors used under reaction conditions that are appropriate for them. There are many requirements for ALD precursors: sufficient volatility, thermal stability and reactivity with substrates and with the films being deposited. In addition, it is easier to produce the required vapors if the precursor is liquid at room temperature, or if it is a solid with melting point below the vaporization temperature, or if it is soluble in an inert solvent with vapor pressure similar to that of the precursor. The precursor vapor should not etch or corrode the substrate or deposited film. Ideally, the precursors should be non-flammable, non-corrosive, non-toxic, simple and non-hazardous to make and inexpensive.
Presenting Author: Roy G. Gordon ([email protected])
Intr
oduc
tion
to
ALD
Prec
urso
rsan
dR
eact
ion
Mec
hani
sms
ALD
Prec
urso
rsan
dR
eact
ion
Mec
hani
sms
Tuto
rial f
or A
LD 2
011
Roy
Gor
don
Roy
Gor
don
Har
vard
Uni
vers
ity
1
Out
line
•Ele
men
ts a
nd M
ater
ials
in A
LD F
ilms
•ALD
Pre
curs
ors
for N
on-M
etal
s
•Typ
es o
f ALD
pre
curs
ors
for M
etal
syp
p
•Typ
esof
ALD
Rea
ctio
nsTy
pes
ofA
LDR
eact
ions
2
ELEM
ENTS
AN
D M
ATE
RIA
LSIN
ALD
FIL
MS
3
List
of t
he S
tabl
e E
lem
ents
by
Sym
bol
Silv
er
Ag
Eur
opiu
m
Eu
Man
gane
se
M
nA
ntim
ony
Sb
gA
lum
inum
A
l A
rgon
A
r A
rsen
ic
A
s
pFl
uorin
e
F
Iron
FeG
alliu
m
G
a
gM
olyb
denu
m
Mo
Nitr
ogen
N
Sod
ium
Na
yS
cand
ium
Sc
Sel
eniu
m S
eS
ilico
n S
i G
old
Au
Bor
on
BB
ariu
m
Ba
Blli
B
Gad
olin
ium
Gd
Ger
man
ium
Ge
Hyd
roge
n
HH
liH
Nio
bium
Nb
Neo
dym
ium
Nd
Neo
n N
eN
ik
lN
i
Sam
ariu
m S
mTi
n S
nS
tront
ium
Sr
Tt
lT
Ber
ylliu
m
Be
Bro
min
e
Br
Car
bon
CC
alci
umC
a
Hel
ium
He
Haf
nium
Hf
Mer
cury
Hg
Hol
miu
mH
o
Nic
kel
Ni
Oxy
gen
OO
smiu
m
O
sP
hosp
horu
sP
Tant
alum
TaTe
rbiu
m
Tb
Tellu
rium
Te
Thal
lium
TlC
alci
um
C
aC
adm
ium
C
dC
eriu
m
Ce
Chl
orin
eC
l
Hol
miu
m
H
oIo
dine
I
Indi
um
InIri
dium
Ir
Pho
spho
rus
P
Lead
P
bP
alla
dium
P
dP
rase
odym
ium
Pr
Thal
lium
Tl
Thul
ium
T
mTi
tani
um
TiTu
ngst
enW
Chl
orin
e
Cl
Cob
alt
Co
Chr
omiu
m
Cr
Ces
ium
Cs
Iridi
umIr
Pot
assi
um
KK
rypt
on
K
rLa
ntha
num
La
Pra
seod
ymiu
mP
rP
latin
um
Pt
Rub
idiu
m
Rb
Rhe
nium
R
e
Tung
sten
WVa
nadi
um V
Xen
on
Xe
Yttr
ium
Y
4
Cop
per
Cu
Dys
pros
ium
Dy
Erb
ium
E
r
Lith
ium
LiLu
tetiu
m
Lu
Mag
nesi
um M
g
Rho
dium
R
hR
uthe
nium
Ru
Sul
fur
S
Ytte
rbiu
m Y
bZi
nc
ZnZi
rcon
ium
Zr
Per
iodi
c Ta
ble
alka
mai
n gr
oup
met
als
met
allo
ids
or
non-
met
als
alkali m
aline eart
h
118
met
als
sem
i-met
als
metals
th metals
halogens
H2
1314
1516
17H
eLi
Be
BC
NO
FN
eN
aM
g3
45
67
89
1011
12A
lSi
PS
Cl
Ar
trans
ition
met
als
s
s
Na
Mg
34
56
78
910
1112
Al
SiP
SC
lA
rK
Ca
ScTi
VC
rM
nFe
Co
Ni
Cu
ZnG
aG
eA
sSe
Br
Kr
Rb
SrY
ZrN
bM
oTc
Ru
Rh
PdA
gC
dIn
SnSb
TeI
XeC
sB
aLa
Hf
TaW
Re
Os
IrPt
Au
Hg
TlPb
Bi
PoA
tR
nC
sB
aLa
Hf
TaW
Re
Os
IrPt
Au
Hg
TlPb
Bi
PoA
tR
nFr
Ra
Ac
Rf
Db
SgB
hH
sM
tD
sR
g
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
Lu
mai
n gr
oup
met
als
lant
hani
des
5
yTh
PaU
Np
PuA
mC
mB
kC
fEs
FmM
dLr
No
actin
ides
Ele
men
ts in
ALD
Film
s
118
H2
1314
1516
17H
e
= el
emen
t in
at le
ast o
ne A
LD fi
lmM
H2
1314
1516
17H
eLi
Be
BC
NO
FN
eN
aM
g3
45
67
89
1011
12A
lSi
PS
Cl
Ar
KC
STi
VC
MF
CN
iC
ZG
GA
SB
KK
Ca
ScTi
VC
rM
nFe
Co
Ni
Cu
ZnG
aG
eA
sSe
Br
Kr
Rb
SrY
ZrN
bM
oTc
Ru
Rh
PdA
gC
dIn
SnSb
TeI
XeC
sB
aLa
Hf
TaW
Re
Os
IrPt
Au
Hg
TlPb
Bi
PoA
tR
nFr
Ra
Ac
Rf
Db
SgB
hH
sM
tD
sR
g
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
LuTh
PaU
Np
PuA
CB
kC
fEs
FmM
dLr
No
ThPa
UN
pPu
Am
Cm
Bk
Cf
EsFm
Md
LrN
o
Not
use
d in
ALD
bec
ause
the
elem
ents
are
6
= ra
dioa
ctiv
e=
high
ly to
xic
= in
ert
= lo
w-v
olat
ility
com
poun
ds
Com
bina
tions
of E
lem
ents
in A
LD F
ilms
ff
Und
erlin
ed e
lem
ents
hav
e be
en d
epos
ited
as p
ure,
sin
gle
elem
ents
ALD
film
s ha
ve b
een
mad
e w
ith c
ombi
natio
ns o
f 2 o
r mor
e el
emen
ts w
ithin
a b
ox
12
1314
15O
ON
OLi
Be
PB
CN
OF
NO
NO
BO
Na
Mg
PAl
PSi
SiP
Na
Mg
PAl
PSi
SiP
Te3
45
67
89
1011
12As
C
OF
NO
NO
OO
NO
NO
NO
NO
NO
NO
FN
OO
KC
aS
ScZr
TiS
VC
rM
nS
FeC
oC
Ni
SC
uS
ZnS
PG
aG
eAs
Hf
AlC
AlTe
TeSe
AsSb
Te
OF
NO
NO
NO
NO
ON
OO
O
Rb
SrS
YS
SiZr
Nb
Mo
TcR
uR
hPd
AgC
dS
PIn
SSn
SSb
TiTi
AlTe
SeAs
SbTe
ON
OF
NO
NO
NO
OO
OC
sB
aS
SiLa
SSi
Hf
TaW
SR
eO
sIr
PtAu
Hg
TlPb
SSi
Bi
Cs
Ba
SSi
LaS
SiH
fTa
WS
Re
Os
IrPt
AuH
gTl
PbS
SiB
i
TiAl
TiAl
CSi
CTe
TiTi
OO
OO
OO
OO
OO
OO
NO
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
Lu
7U
pdat
ed ta
ble
from
R. P
uuru
nen,
J. A
ppl.
Phy
s.97
, 121
301
(200
5)
ALD
Mat
eria
ls b
y Ty
peO
xide
die
lect
rics
Al 2O
3, Ti
O2,
ZrO
2, H
fO2,
Ta2O
5, N
b 2O
5, Sc
2O3,
Y 2O
3, M
gO, B
2O3,
SiO
2,G
OL
OC
OP
ON
dO
SO
EO
Gd
OD
OH
OG
eO2,
La2O
3,C
eO2,
PrO
x,N
d 2O
3,Sm
2O3,
EuO
x,G
d 2O
3,D
y 2O
3,H
o 2O
3,Er
2O3,
Tm2O
3, Yb
2O3,
Lu2O
3, Sr
TiO
3, B
aTiO
3, Pb
TiO
3, Pb
ZrO
3, B
i xTi yO
,B
i xSi yO
, SrT
a 2O
6, Sr
Bi 2T
a 2O
9, YS
cO3,
LaA
lO3,
NdA
lO3,
GdS
cO3,
LaSc
O3,
LaLu
O3,
LaYb
O3,
Er3G
a 5O
133,
3,3,
35
13O
xide
con
duct
ors
orse
mic
ondu
ctor
sIn
2O3,
In2O
3:Sn
, In 2
O3:
F, In
2O3:
Zr, S
nO2,
SnO
2:Sb
, Sb 2
O3,
ZnO
, ZnO
:Al,
ZnO
:B, Z
nO:G
a, R
uO2,
RhO
2, IrO
2, G
a 2O
3, VO
2, V 2
O5,
WO
3, W
2O3,
NiO
, C
uOx,
FeO
x, C
rOx,
CoO
x, M
nOx
Oth
tid
LC
OL
NiO
LM
OL
CM
OO
ther
tern
ary
oxid
esLa
CoO
3,La
NiO
3,La
MnO
3,La
1-xC
a xM
nO3
Nitr
ide
diel
ectr
ics
orse
mic
ondu
ctor
sB
N, A
lN, G
aN, I
nN, S
i 3N4,
Ta3N
5, C
u 3N
, Zr 3
N4,
Hf 3
N4,
LaN
, LuN
Met
allic
nitr
ides
TiN
, Ti-S
i-N, T
i-Al-N
, TaN
, NbN
, MoN
, WN
x, W
NxC
y, C
o xN
, Sn x
N,
,,
,,
,x,
xy,
x,
xII-
VI s
emic
ondu
ctor
sZn
S, Z
nSe,
ZnT
e, C
aS, S
rS, B
aS, C
dS, C
dTe,
MnT
e, H
gTe
II-VI
bas
edph
osph
ors
ZnS:
M(M
=Mn,
Tb,T
m);
CaS
:M(M
=Eu,
Ce,
Tb,
Pb)
; SrS
:M(M
=Ce,
Tb, P
b)III
-V s
emic
ondu
ctor
sG
aAs,
AlA
s, A
lP, I
nP, G
aP, I
nAs
Flid
CF
SF
MF
LF
ZF
Fluo
rides
CaF
2,Sr
F 2,M
gF2,
LaF 3
,ZnF
2El
emen
tsR
u, P
t, Ir,
Pd,
Rh,
Ag,
Cu,
Ni,
Co,
Fe,
Mn,
Ta,
W, M
o, T
i, A
l, Si
, Ge
Oth
erse
mic
ondu
ctor
sPb
S, S
nS, I
n 2S 3
, Sb 2
S 3, C
u xS,
CuG
aS2,
WS 2
, SiC
, Ge 2
Sb2T
e 5O
ther
sLa
SY
OS
TiC
TiS
TaC
WC
Ca
(PO
)C
aCO
orga
nics
8
Oth
ers
La2S
3,Y 2
O2S
,TiC
x,Ti
S 2,T
aCx,
WC
x,C
a 3(P
O4)
2,C
aCO
3,or
gani
cs
Ada
pted
from
M. R
itala
and
J. N
iinis
to, i
n C
hem
ical
Vap
or D
epos
ition
(Roy
al S
ocie
ty o
f Che
mis
try, 2
009)
ALD
PREC
UR
SOR
SA
LDPR
ECU
RSO
RS
FOR
NO
N-M
ETA
LSox
ygen
nitr
ogen
nitr
ogen
fluor
ine,
car
bon
sulfu
r, se
leni
um, t
ellu
rium
phos
phor
us, a
rsen
ic, a
ntim
ony
9
Non
-Met
als
Impo
rtant
in A
LD F
ilms
O =
Oxy
gen
N =
Nitr
ogen
C =
Car
bon
F =
Fluo
rine
118
ygS
= Su
lfur
Se =
Sel
eniu
m
gP
= Ph
osph
orus
H2
1314
1516
17H
eLi
Be
BC
NO
FN
e
Na
Mg
34
56
78
910
1112
Al
SiP
SC
lA
r
KC
aSc
TiV
Cr
Mn
FeC
oN
iC
uZn
Ga
Ge
As
SeB
rK
r
Rb
SrY
ZrN
bM
oTc
Ru
Rh
PdA
gC
dIn
SnSb
TeI
XeR
bSr
YZr
Nb
Mo
TcR
uR
hPd
Ag
Cd
InSn
SbTe
IXe
Cs
Ba
LaH
fTa
WR
eO
sIr
PtA
uH
gTl
PbB
iPo
At
Rn
FrR
aA
cR
fD
bSg
Bh
Hs
Mt
Ds
Rg
10
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
LuTh
PaU
Np
PuA
mC
mB
kC
fEs
FmM
dLr
No
ALD
Pre
curs
ors
for O
xyge
nW
ater
vapo
rH
2OW
ater
vapo
r,H
2O
Hyd
roge
n pe
roxi
de, H
2O2,
som
etim
es m
ore
reac
tive
than
H2O
(alw
ays
acco
mpa
nied
by
wat
er)
Di-o
xyge
nO
2th
eco
mm
onfo
rmof
oxyg
enin
the
air
(y
py
)
Alc
ohol
s, R
OH
, suc
h as
met
hano
l CH
3OH
or e
than
ol C
2H5O
H
Dio
xyge
n,O
2,th
eco
mm
onfo
rmof
oxyg
enin
the
air
Ozo
ne, O
3, a
mor
e re
activ
e fo
rm o
f oxy
gen,
mad
e in
a p
lasm
a,
can
flow
thro
ugh
tubi
ng;(
alw
ays
acco
mpa
nied
by
O2)
gg
(y
py
2)
Oxy
gen
atom
s, c
reat
ed in
a p
lasm
a cl
ose
to a
sub
stra
te s
urfa
ce;
so re
activ
e th
at th
ey c
an’t
trave
l far
thro
ugh
tubi
ng w
ithou
t re
com
bini
ng to
form
O2
Nitr
ogen
dio
xide
,NO
2(a
lway
s ac
com
pani
ed b
y its
dim
er N
2O4)
11
ALD
Pre
curs
ors
forN
itrog
enA
LDP
recu
rsor
sfo
rNitr
ogen
Am
mon
ia, N
H3
Hyd
razi
ne, N
2H4,
is m
ore
reac
tive
than
NH
3, bu
t tox
ic &
exp
losi
ve
Pla
sma-
activ
ated
NH
3is
mor
e re
activ
e th
an N
H3
Din
itrog
en, N
2, is
nor
mal
ly u
nrea
ctiv
e un
der A
LD c
ondi
tions
Pl
tit
dN
iti
thN
Pla
sma-
activ
ated
N2
is m
ore
reac
tive
than
N2
Nitr
ic o
xide
, NO
, can
be
used
for n
itrog
en-d
opin
g of
oxi
des
12
ALD
Pre
curs
ors
for C
arbo
n
Ace
tyle
ne g
asC
CH
H
Form
ic a
cid
vapo
rCH
Car
bon
cont
aine
d in
a m
etal
com
poun
d
OO
H
ALD
Pre
curs
ors
for F
luor
ine
Hyd
roge
n flu
orid
e ga
s, H
F
Fli
ti
di
tl
dh
WF
13
Fluo
rine
cont
aine
din
a m
etal
com
poun
d su
ch a
s W
F 6
ALD
Pre
curs
ors
for
Sul
fur
Sel
eniu
man
dTe
lluriu
mS
ulfu
r,S
elen
ium
and
Tellu
rium
Ele
men
tal s
ulfu
r vap
or, S
n
Hyd
roge
n su
lfide
gas
, H2S
(po
ison
ous,
but
suf
ficie
nt w
arni
ng b
y sm
ell,
if no
t chr
onic
ally
exp
osed
)
Hyd
roge
n se
leni
de g
as, H
2Se
(ve
ry p
oiso
nous
, with
out
suffi
cien
t war
ning
by
smel
l)
Bis
(trie
thyl
sily
l)sel
eniu
m, (
Et 3S
i) 2S
e
Bis
(trie
thyl
sily
l)tel
luriu
m, (
Et 3S
i) 2Te
14
ALD
Pre
curs
ors
for
Pho
spho
rus
Ars
enic
and
Ant
imon
yP
hosp
horu
s,A
rsen
ican
dA
ntim
ony
phos
phin
e ga
s, P
H3
(ver
y po
ison
ous)
arsi
ne g
as, A
sH3
(ver
y po
ison
ous)
H3C
CH
3an
timon
y tri
chlo
ride,
SbC
l 3
tris(
dim
ethy
lam
ido)
antim
ony
N SbN
NC
H3
H3C
NN C
H3
CH
3
15
Ele
men
tal A
LD P
recu
rsor
sEx
ampl
es:
Non
-met
als
O2,
P 4, S
2or
S 8M
etal
s:M
gM
nZn
Met
als:
Mg,
Mn,
Zn
Adv
anta
ge: h
igh
purit
yD
isad
vant
age:
low
vol
atili
ty (m
etal
s)
118
H2
1314
1516
17H
eLi
Be
BC
NO
FN
eN
aM
g3
45
67
89
1011
12A
lSi
PS
Cl
Ar
KC
aSc
TiV
Cr
Mn
FeC
oN
iC
uZn
Ga
Ge
As
SeB
rK
rR
bSr
YZr
Nb
Mo
TcR
uR
hPd
Ag
Cd
InSn
SbTe
IXe
gC
sB
aLa
Hf
TaW
Re
Os
IrPt
Au
Hg
TlPb
Bi
PoA
tR
nFr
Ra
Ac
Rf
Db
SgB
hH
sM
tD
sR
g
16
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
LuTh
PaU
Np
PuA
mC
mB
kC
fEs
FmM
dLr
No
TYPE
S O
F A
LD P
REC
UR
SOR
S FO
RM
ETA
LSFO
RM
ETA
LSpu
re e
lem
ents
met
al h
ydrid
es
fm
etal
hal
ides
: flu
orid
es, c
hlor
ides
, bro
mid
es, i
odid
es
met
al-c
arbo
n bo
nds:
alk
yls,
cyc
lope
ntad
ieny
lsy
,y
py
met
al-o
xyge
n bo
nds:
alk
oxid
es, b
eta-
dike
tona
tes
met
al-n
itrog
en b
onds
: am
ides
, im
ides
, am
idin
ates
17
Met
al C
ompo
unds
for A
LDM
ost m
etal
com
poun
ds u
sed
in A
LD h
ave
1 or
2 m
etal
ato
ms,
M,
com
bine
d w
ith 1
or m
ore
“lig
ands
”, L
, w
ritte
n as
mon
omer
s M
L nor
dim
ers
M2L
n, w
here
n =
1, 2
, 3, 4
, 5 o
r 6.
The
ligan
ds, L
, con
tain
1 o
r mor
e no
n-m
etal
ato
ms.
Tht
lt
Mb
idd
th
>1it
fiti
hTh
e m
etal
ato
ms,
M, m
ay b
e co
nsid
ered
toha
ve>1
uni
ts o
f pos
itive
cha
rge.
Met
als
with
1 u
nit o
f pos
itive
cha
rge
M+
may
be
writ
ten
M(I)
,an
dar
esa
idto
bein
oxid
atio
nst
ate
+1an
dar
esa
idto
bein
oxid
atio
nst
ate
+1.
Met
als
with
2 u
nits
of p
ositi
ve c
harg
e M
2+m
ay b
e w
ritte
n M
(II),
and
are
said
tobe
inox
idat
ion
stat
e+2
,etc
.an
dar
esa
idto
bein
oxid
atio
nst
ate
2,et
c.
Mos
t lig
ands
use
d in
ALD
can
be
cons
ider
ed to
hav
e el
ectr
ical
cha
rge
-1.
A fe
w li
gand
s, e
.g. o
xide
s (O
2-) a
nd im
ides
(NC
xH2x
+1)2
- , ha
ve c
harg
e -2
.
18
gg
()
(x
2x1)
g
The
tota
l cha
rges
of t
he m
etal
and
liga
nds
in a
pre
curs
or m
ust a
dd to
zer
o.
Type
s of
Met
al P
recu
rsor
s fo
r ALD
R
M
N
R
M
Alky
limid
es
19
Ele
men
ts w
ith H
ydrid
e A
LD P
recu
rsor
s
Hyd
rides
are
com
poun
ds o
f an
elem
ent X
and
hyd
roge
n
118
XHn
n =
1, 2
, 3 o
r 41
18H
213
1415
1617
He
LiB
eB
CN
OF
Ne
Na
Mg
34
56
78
910
1112
Al
SiP
SC
lA
rN
aM
g3
45
67
89
1011
12A
lSi
PS
Cl
Ar
KC
aSc
TiV
Cr
Mn
FeC
oN
iC
uZn
Ga
Ge
As
SeB
rK
rR
bSr
YZr
Nb
Mo
TcR
uR
hPd
Ag
Cd
InSn
SbTe
IXe
CB
LH
fT
WR
OI
PtA
HTl
PbB
iP
At
RC
sB
aLa
Hf
TaW
Re
Os
IrPt
Au
Hg
TlPb
Bi
PoA
tR
nFr
Ra
Ac
Rf
Db
SgB
hH
sM
tD
sR
g
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
Lu
20
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
LuTh
PaU
Np
PuA
mC
mB
kC
fEs
FmM
dLr
No
Exa
mpl
es o
f Hyd
ride
Pre
curs
ors
Si
H
H
HSi
H4
= si
lane
H
Si
SiH
H
H
HSi
2H6
= di
sila
ne,
mor
ere
activ
eth
ansi
lane
HH
mor
ere
activ
eth
ansi
lane
GeH
=ge
rman
eG
H
H
HG
eH4
=ge
rman
eG
eH
H
H
AlH
3N
Me 3
= al
umin
um h
ydrid
e –
trim
ethy
lam
ine
Adv
anta
ge:
Dis
adva
nta g
es:
21
gve
ry v
olat
ileg
usua
lly n
eed
plas
ma
activ
atio
npy
roph
oric
and
toxi
c
Ele
men
ts w
ith H
alid
e A
LD P
recu
rsor
s
Hal
ides
are
com
poun
ds o
f an
elem
ent M
and
a h
alog
en X
= F
, Cl,
Br o
r I
halo
gens
MX n
n =
1, 2
, 3, 4
, 5 o
r 6
118
H2
1314
1516
17H
eLi
Be
BC
NO
FN
eLi
Be
BC
NO
FN
eN
aM
g3
45
67
89
1011
12A
lSi
PS
Cl
Ar
KC
aSc
TiV
Cr
Mn
FeC
oN
iC
uZn
Ga
Ge
As
SeB
rK
rR
bSr
YZr
Nb
Mo
TcR
uR
hPd
Ag
Cd
InSn
SbTe
IXe
Rb
SrY
ZrN
bM
oTc
Ru
Rh
PdA
gC
dIn
SnSb
TeI
XeC
sB
aLa
Hf
TaW
Re
Os
IrPt
Au
Hg
TlPb
Bi
PoA
tR
nFr
Ra
Ac
Rf
Db
SgB
hH
sM
tD
sR
g
22
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
LuTh
PaU
Np
PuA
mC
mB
kC
fEs
FmM
dLr
No
Exa
mpl
es o
f Hal
ide
ALD
Pre
curs
ors
WF 6
= tu
ngst
en h
exaf
luor
ide
TiC
ltit
it
thl
id
Oxy
gen
can
be c
ombi
ned
with
ha
lide
ligan
ds:
TiC
l 4=
titan
ium
tetr
achl
orid
e
HfC
l 4=
hafn
ium
tetr
achl
orid
e
VOC
l 3=
tric
hlor
ooxo
vana
dium
= va
nadi
um o
xide
tric
hlor
ide
= va
nady
l tric
hlor
ide
CrO
2Cl 2
= di
chlo
rodi
oxoc
hrom
ium
= ch
rom
ium
dic
hlor
ide
diox
ide
=ch
rom
yldi
chlo
ride
SnC
l 4=
tin te
trac
hlor
ide
=ch
rom
yldi
chlo
ride
Adv
anta
ges:
ther
mal
ly s
tabl
eus
ually
inex
pens
ive
GeC
l 2·di
oxan
eO
Dis
adva
ntag
es:
halo
gen
impu
ritie
s in
film
si
bd
tC
H2
H2C
H2C
OC
H2
GeC
l 2
23
corr
osiv
eby
prod
ucts
low
vol
atili
ty fo
r som
e el
emen
tsC
H2
OH
2C
Met
al A
lkyl
ALD
Pre
curs
ors
(CH
3)3A
l = tr
imet
hyla
lum
inum
H2
H2
(3)
3y
H3C
H2
CZn
H2
CC
H3
(CH
3CH
2)2Z
n =
diet
hylz
inc
Ad
tl
tilhi
hlti
iA
LDA
dvan
tage
: vol
atile
,hig
hly
reac
tive
inA
LD
Dis
adva
ntag
e: h
azar
dous
, bur
st in
to fl
ame
in a
ir (p
yrop
horic
)
i Pr 2
Te =
diis
opro
pylte
lluriu
mH
3CC
HH
3CTe
CH
CH
3
CH
3
24
33
Ele
men
tsw
ithA
lkyl
ALD
Pre
curs
ors
Ele
men
tsw
ithA
lkyl
ALD
Pre
curs
ors
118
H2
1314
1516
17H
eLi
Be
BC
NO
FN
eN
aM
g3
45
67
89
1011
12A
lSi
PS
Cl
Ar
KC
aSc
TiV
Cr
Mn
FeC
oN
iC
uZn
Ga
Ge
As
SeB
rK
rR
bSr
YZr
Nb
Mo
TcR
uR
hPd
Ag
Cd
InSn
SbTe
IXe
Cs
Ba
LaH
fTa
WR
eO
sIr
PtA
uH
gTl
PbB
iPo
At
Rn
FrR
aA
cR
fD
bSg
Bh
Hs
Mt
Ds
Rg
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
LuTh
PaU
Np
PuA
mC
mB
kC
fEs
FmM
dLr
No
25
Cyc
lope
ntad
ieny
l Lig
ands
H
HC
CHC
H
H CH
CC
p =
cycl
open
tadi
enyl
MeC
p =
met
hylc
yclo
pent
adie
nyl
Me 5
Cp
= C
p* =
pen
tam
ethy
lcyc
lope
ntad
ieny
lC
CCC
C
CH
3
H3C
CH
3
EtC
p=
ethy
lcyc
lope
ntad
ieny
l
CC
H3C
CH
3
EtC
p=
ethy
lcyc
lope
ntad
ieny
l
26
i PrC
p =
isop
ropy
lcyc
lope
ntad
ieny
l
Exa
mpl
es o
f Cyc
lope
ntad
ieny
l Pre
curs
ors
Cp 2
Ni =
bis
(cyc
lope
ntad
ieny
l)nic
kel(I
I)
(EtC
p)2R
u =
bis(
ethy
lcyc
lope
ntad
ieny
l)rut
heni
um(II
)
(Me 5
Cp)
2Sr =
bis
(pen
tam
ethy
lcyc
lope
ntad
ieny
l)str
ontiu
m
(i PrC
p)3L
a =
tris
(isop
ropy
lcyc
lope
ntad
ieny
l)lan
than
um
Cp 2
Me 2
Zr =
(dic
yclo
pent
adie
nyl)(
dim
ethy
l)zirc
oniu
m
27
(MeC
p)(M
e)3P
t = (m
ethy
lcyc
lope
ntad
ieny
l)(tr
imet
hyl)p
latin
um(IV
)
Cyc
lope
ntad
ieny
lALD
Pre
curs
ors
118
H2
1314
1516
17H
e
LiB
eB
CN
OF
Ne
Na
Mg
34
56
78
910
1112
Al
SiP
SC
lA
rK
Ca
ScTi
VC
rM
nFe
Co
Ni
Cu
ZnG
aG
eA
sSe
Br
Kr
Rb
SrY
ZrN
bM
oTc
Ru
Rh
PdA
gC
dIn
SnSb
TeI
Xeg
Cs
Ba
LaH
fTa
WR
eO
sIr
PtA
uH
gTl
PbB
iPo
At
Rn
FrR
aA
cR
fD
bSg
Bh
Hs
Mt
Ds
Rg
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
Lu
ThPa
UN
pPu
Am
Cm
Bk
Cf
EsFm
Md
LrN
o
Adv
anta
ges:
ther
mal
ly s
tabl
eD
isad
vant
ages
:so
me
have
low
reac
tivity
(Ni,
Ru)
lid(N
iS
MI
L) 28
som
e ar
e so
lids
(Ni,
Sr, M
g,In
,La)
som
e ha
ve lo
w v
olat
ility
(La,
Sr,
Mg)
Alk
oxid
e C
ompo
unds
MO
CH
3M
OC
CH
3
CH
3CH
3
OM
e =
met
hoxy
Ot B
u =
tert-
buto
xy
MO
C H2
CH
3O
Et =
eth
oxy
MO
CC
H3
CH
2CH
3H
3CO
t Pe
= te
rt-pe
ntox
y
MO
CH
CH
3
CH
3M
OC
C H
OC
H3
CH
3
C
Oi P
r = is
opro
poxy
mm
p =
1-m
etho
xy-
2-m
eth y
l-2-p
ropo
xy
23
MO
H2
CC
HC
H3
3H
2H
3C
MO
C H
H2
CN
CH
3O
i Bu
= is
obut
oxy
yp
py
dmae
= d
imet
hyla
min
o-et
hoxy
OH
2CC
H3
H2
CH
3
Os B
u=
sec-
buto
xy
etho
xy
OH
2C
CH
3H
3Cdm
amp
= 1
dih
li
29
MC
H
CH
3
CH
3O
Buse
cbu
toxy
MC
N CH
3
3
CH
3
1-di
met
hyla
min
o-2-
met
hyl-2
-pro
poxy
Alk
oxid
e C
ompo
unds
Use
d in
ALD
Al(O
Et) 3
= tr
is(e
thox
y)al
umin
um =
alu
min
um e
thox
ide
AlM
e 2(O
i Pr)
= is
opro
poxy
dim
ethy
lalu
min
umB
(OM
e)3=
tris
(met
hoxy
)bor
on =
trim
ethy
lbor
ate
() 3
(y)
yH
f(Ot B
u)4
= te
tra(
tert
-but
oxy)
hafn
ium
= h
afni
um te
rt-b
utox
ide
Hf(m
mp)
4=
tetr
a(1-
met
hoxy
-2-m
ethy
l-2-p
ropo
xy)h
afni
umN
b(O
Et) 5
= pe
nta(
etho
xy)n
iobi
um =
nio
bium
eth
oxid
eN
i(dm
amp)
2=
bis(
1-di
met
hyla
min
o-2-
met
hyl-2
-pro
poxy
)nic
kel(I
I)Pb
(Ot B
u)2
= bi
s(te
rt-b
utox
y)le
ad(II
) = le
ad(II
) ter
t-but
oxid
eSi
(OEt
) 4=
tetr
a(et
hoxy
)sila
ne =
tetr
aeth
ylor
thos
ilica
te =
TEO
SSi
(Ot B
)O
Ht
i(t
tbt
)il
lSi
(Ot B
u)3O
H =
tris
(tert
-but
oxy)
sila
nol
Si(O
t Pe)
3OH
= tr
is(te
rt-p
ento
xy)s
ilano
lTa
(OEt
) 5=
pent
a(et
hoxy
)tant
alum
= ta
ntal
um e
thox
ide
Ti(O
Me)
=te
tra(
met
hoxy
)tita
nium
=tit
aniu
mm
etho
xide
Ti(O
Me)
4=
tetr
a(m
etho
xy)ti
tani
um=
titan
ium
met
hoxi
deTi
(OEt
) 4=
tetr
a(et
hoxy
)tita
nium
= ti
tani
um e
thox
ide
Ti(O
i Pr)
4=
tetr
a(is
opro
poxy
)tita
nium
= ti
tani
um is
opro
poxi
deVO
(Oi P
r)3=
tris
(isop
ropo
xy)o
xova
nadi
um=
vana
dyli
sopr
opox
ide
30
VO(O
Pr) 3
tris
(isop
ropo
xy)o
xova
nadi
umva
nady
liso
prop
oxid
e
Ele
men
ts w
ith A
lkox
ide
ALD
Pre
curs
ors
118
H2
1314
1516
17H
eLi
Be
BC
NO
FN
eN
aM
g3
45
67
89
1011
12A
lSi
PS
Cl
Ar
KC
aSc
TiV
Cr
Mn
FeC
oN
iC
uZn
Ga
Ge
As
SeB
rK
rR
bSr
YZr
Nb
Mo
TcR
uR
hPd
Ag
Cd
InSn
SbTe
IXe
gC
sB
aLa
Hf
TaW
Re
Os
IrPt
Au
Hg
TlPb
Bi
PoA
tR
nFr
Ra
Ac
Rf
Db
SgB
hH
sM
tD
sR
g
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
LuTh
PaU
Np
PuA
mC
mB
kC
fEs
FmM
dLr
No
Adv
anta
ges:
reac
tive
to w
ater
vap
or =
> ox
ides
Dis
adva
ntag
es:
limite
d th
erm
al s
tabi
lity
nots
uita
ble
form
akin
gni
trid
es
31
nots
uita
ble
form
akin
gni
trid
esno
t sui
tabl
e fo
r mak
ing
pure
met
als
Bet
a-di
keto
nate
Com
poun
ds4
equi
vale
nt w
ays
to re
pres
ent a
met
al a
cety
lace
tona
te (a
cac)
:
loca
lized
bond
ing
it
1
loca
lized
bond
ing
it
2
delo
caliz
edbo
ndin
gi
t1
delo
caliz
edbo
ndin
gpi
ctre
2H C
CC
H3C
CH
3H C
CH
3CC
H3
H CH
3CC
H3
H2
CC
HC
HH
3CC
H3
pict
ure
1pi
ctur
e2
pict
ure
1pi
ctur
e2
OM
OO
MO
OM
OO
MO
32
Bet
a-di
keto
nate
Com
poun
dsH C
CC
F 3C
CF 3
H CC
CC
CH C
CC
H3C
CH
3
CH
3H
3C H3C
H3C
CH
3
CH
3O
MO
1,1,
1,5,
5,5-
hexa
fluor
o-
OM
O
2,2,
6,6-
tetra
met
hyl-
ht
35
dit
OM
O
pent
ane-
2,4-
dion
ate,
or
H3C
CH
3
,,
,5,5
,5e
auo
oac
etyl
acet
onat
e (h
fac)
hept
ane-
3,5-
dion
ate
(thd
or t
mhd
)
pea
e,
do
ae,
oac
etyl
acet
onat
e (a
cac)
(mor
e vo
latil
e)(m
ore
bulk
y)
H CC
C
H2
CC
H3
C H
H2
CH
3C
H CC
CC H
OC H
H2
CO
H3C
CH
3H
3CC
H3
CH
3
OM
OH
23
octa
ne-2
4-di
onat
e(o
d)
OM
OH
2H
2C
H3
1-(2
-met
hoxy
etho
xy)-
2,2,
6,6-
tetra
met
hyl-
CH
3 33
octa
ne-2
,4-d
iona
te(o
d)he
ptan
e-3,
5-di
onat
e(m
ethd
)(lo
wer
mel
ting
poin
t)(v
ery
bulk
y)
Bet
a-di
keto
nate
ALD
Pre
curs
ors
Ba(
thd)
2C
e(th
d)4
Mg(
thd)
2M
n(th
d)3
Adv
anta
ges:
non-
reac
tive
toam
bien
tair
Co(
acac
) 2C
o(ac
ac) 3
Co(
thd)
3C
()
Nd(
thd)
3N
i(aca
c)2
Ni(t
hd) 2
Pb(th
d)
non
reac
tive
toam
bien
tair
high
ther
mal
sta
bilit
y
Dis
adva
ntag
es:
Cr(
acac
) 3C
u(hf
ac) 2
Cu(
thd)
2D
y(th
d)
Pb(th
d)2
Pd(h
fac)
2Pd
(thd)
2Pt
(aca
c)
Dis
adva
ntag
es:
low
vap
or p
ress
ure
(exc
ept C
u(hf
ac) 2
)so
lids
with
hig
h m
eltin
g po
ints
low
reac
tivity
tow
ater
vapo
rD
y(th
d)3
Er(th
d)3
Eu(th
d)3
Fe(a
cac)
3
Pt(a
cac)
2R
u(th
d)3
Ru(
od) 3
Sc(th
d)3
low
reac
tivity
tow
ater
vapo
rno
t sui
tabl
e fo
r mak
ing
nitr
ides
Fe(a
cac)
3Fe
(thd)
3G
d(th
d)3
Ho(
thd)
3
Sc(th
d)3
Sm(th
d)3
Sr(th
d)2
Sr(m
ethd
) 2
34
() 3
Ir(ac
ac) 3
La(th
d)3
() 2
Tm(th
d)3
Y(th
d)3
Bet
a-di
keto
nate
ALD
Pre
curs
ors
118
H2
1314
1516
17H
eLi
Be
BC
NO
FN
eLi
Be
BC
NO
FN
eN
aM
g3
45
67
89
1011
12A
lSi
PS
Cl
Ar
KC
aSc
TiV
Cr
Mn
FeC
oN
iC
uZn
Ga
Ge
As
SeB
rK
rR
bSr
YZr
Nb
Mo
TcR
uR
hPd
Ag
Cd
InSn
SbTe
IXe
Rb
SrY
ZrN
bM
oTc
Ru
Rh
PdA
gC
dIn
SnSb
TeI
XeC
sB
aLa
Hf
TaW
Re
Os
IrPt
Au
Hg
TlPb
Bi
PoA
tR
nFr
Ra
Ac
Rf
Db
SgB
hH
sM
tD
sR
g
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
LuTh
PaU
Np
PuA
mC
mB
kC
fEs
FmM
dLr
No
35
Am
ide
Liga
nds CH
3
MN
CH
3
CH
3
NM
e 2 =
dim
ethy
lam
ino
= di
met
hyla
mid
o
MNH
2C CH
3
CH
3
NE
tMe
= et
hylm
ethy
lam
ino
= et
hylm
ethy
lam
ido
NE
t 2 =
die
thyl
amin
o =
diet
hyla
mid
oM
NH2C
HC
CH
3
CH
H2C
CH
3
MN
Si
CH
3
CH
3H
3C
N(S
iMe 3
) 2=
bis(
trim
ethy
lsily
l)am
ido
=bi
s(tri
met
hyls
ilyl)a
min
o
CH
MN
Si
CH
3
CH
3H
3C
N(S
iMe 3
) 2bi
s(tri
met
hyls
ilyl)a
mid
obi
s(tri
met
hyls
ilyl)a
min
o
36
Nt B
u =
tert-
buty
limin
o =
tert-
buty
limid
oM
NC
CH
3
CH
3
CH
3
Am
ide
and
Imid
eP
recu
rsor
s fo
r ALD
Al(N
Me 2
) 3=
tris
(dim
ethy
lam
ido)
alum
inum
= A
l 2(N
Me 2
) 6=
hexa
kis(
dim
ethy
lam
ido)
dial
umin
umB
i [N(S
iMe 3
) 2] 3
= tr
is(b
is(tr
imet
hyls
ilyl)a
mid
o)bi
smut
h[
(3)
2]3
((
yy
))
Hf(N
Me 2
) 4=
tetr
akis
(dim
ethy
lam
ido)
hafn
ium
Hf(N
EtM
e)4
= te
tra(
ethy
lmet
hyla
mid
o)ha
fniu
m =
TEM
AH
Hf(N
Et2)
4=
tetr
akis
(die
thyl
amid
o)ha
fniu
m =
TD
EAH
La[N
(SiM
e 3) 2
] 3=
tris
(bis
(trim
ethy
lsily
l)am
ido)
lant
hanu
mPr
[N(S
iMe 3
) 2] 3
= tr
is(b
is(tr
imet
hyls
ilyl)a
mid
o)pr
aseo
dym
ium
Ta(N
Me 2
) 5=
pent
akis
(dim
ethy
lam
ido)
tant
alum
T(N
Et)
tki
(di
thl
id)t
tl
Ta(N
Et2)
5=
pent
akis
(die
thyl
amid
o)ta
ntal
umTa
(NtB
u)(N
Et2)
3=
(tert
-but
ylim
ido)
tris
(die
thyl
amid
o)ta
ntal
umTi
(NM
e 2) 4
= te
trak
is(d
imet
hyla
mid
o)tit
aniu
mTi
(NEt
Me)
=te
tra(
ethy
lmet
hyla
mid
o)tit
aniu
m=
TEM
ATTi
(NEt
Me)
4=
tetr
a(et
hylm
ethy
lam
ido)
titan
ium
=TE
MAT
W(N
tBu)
2(N
Me 2
) 2=
bis(
tert
-but
ylim
ido)
bis(
dim
ethy
lam
ido)
tung
sten
Zn[N
(SiM
e 3) 2
] 2=
bis(
bis(
trim
ethy
lsily
l)am
ido)
zinc
Zr(N
Me2
) 4=
tetr
akis
(dim
ethy
lam
ido)
zirc
oniu
m
37
Zr(N
Me2
) 4te
trak
is(d
imet
hyla
mid
o)zi
rcon
ium
Zr(N
EtM
e)4
= te
tra(
ethy
lmet
hyla
mid
o)zi
rcon
ium
= T
EMA
ZZr
(NEt
2)4
= te
trak
is(d
ieth
ylam
ido)
zirc
oniu
m =
TD
EAZ
Am
ide
and
Imid
eP
recu
rsor
s fo
r ALD
118
H2
1314
1516
17H
eLi
Be
BC
NO
FN
eLi
Be
BC
NO
FN
eN
aM
g3
45
67
89
1011
12A
lSi
PS
Cl
Ar
KC
aSc
TiV
Cr
Mn
FeC
oN
iC
uZn
Ga
Ge
As
SeB
rK
rR
bS
YZ
Nb
MT
RR
hPd
AC
dI
SSb
TI
XR
bSr
YZr
Nb
Mo
TcR
uR
hPd
Ag
Cd
InSn
SbTe
IXe
Cs
Ba
LaH
fTa
WR
eO
sIr
PtA
uH
gTl
PbB
iPo
At
Rn
FrR
aA
cR
fD
bSg
Bh
Hs
Mt
Ds
Rg
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
LuTh
PaU
Np
PuA
mC
mB
kC
fEs
FmM
dLr
No
Adv
anta
ges:
high
ly re
activ
eit
blf
idd
itid
Dis
adva
ntag
es:
limite
d th
erm
al s
tabi
lity
ilii
itf
ill
id
38
suita
ble
for o
xide
s an
d ni
trid
ess i
licon
impu
rity
from
sily
lam
ides
Am
idin
ate
Com
poun
ds4
equi
vale
nt w
ays
to re
pres
ent a
met
al a
mid
inat
e:
loca
lized
bond
ing
loca
lized
bond
ing
delo
caliz
edbo
ndin
g 1
delo
caliz
edbo
ndin
gpi
ctur
e 1
pict
ure
2pi
ctur
e1
pict
ure
2
13
R2
13
R2
13
R2
13
R2
R1
NN
R3
M
R1
NN
R3
M
R1
NN
R3
M
R1
NN
R3
M
R1 ,
R2
and
R3
are
non-
met
als,
usu
ally
alk
yl g
roup
s C
xH2x
+1;
othe
r non
-met
als,
suc
h as
sili
con
or n
itrog
en m
ay b
e in
clud
ed.
39
Som
e A
mid
inat
e Li
gand
s
N,N
’-dim
ethy
l-fo
rmam
idin
ate
(Me 2
fmd)
N,N
’-die
thyl
-fo
rmam
idin
ate
(Et 2
fmd)
N,N
’-diis
opro
pyl-
form
amid
inat
e(i P
r 2fm
d)
N,N
’-dim
ethy
l-ac
etam
idin
ate
(t Bu 2
amd)
N,N
’-di-s
ec-b
utyl
-ac
etam
idin
ate
(sB
u 2am
d)
HH
Incr
easi
ng s
teric
bul
k
C H2
NCC
H2 N
CCH
3
CH
3
H2
CC H
2
H3C
H3C
M
C H2
NCC
H2 N
CCH
3
CH
3
H2
CH
3C
H3C
M
C H2
NCC
H2 N
CCH
3
CH
3
H3C
H3C
M
C H2
NCC
H3 N
CCH
3
CH
3
H3C
M
CH
3
MC
H3
MC
H3
MC
H3
N’-t
ert-b
utyl
-N
-eth
yl-
acet
amid
inat
e
N’-t
ert-b
utyl
-N
-eth
yl-
prop
iona
mid
inat
e
N’-t
ert-b
utyl
-N
-eth
yl-
but y
ram
idin
ate
N-e
thyl
-N’-
tert
-but
yl-
pent
ylam
idin
ate
40
(t BuE
t-am
d)(t B
uEt-p
md)
y(t B
uEt-b
md)
py
(t BuE
t-pem
d)
Incr
easi
ng fl
exib
ility
lead
s to
dec
reas
ing
mel
ting
poin
ts a
nd li
quid
s
Am
idin
ate
Com
poun
ds U
sed
in A
LDA
g 2(t B
u 2-a
md)
2C
a(t B
u 2-a
md)
2C
o(i P
r-a
md)
Lu(E
t 2-fm
d)3
Lu(E
t 2-a
md)
3M
g(t B
uam
d)
Adv
anta
ges:
high
reac
tivity
to w
ater
=>
oxid
esC
o(Pr
2-am
d)2
Co(
t BuE
t-am
d)2
Cr(
Et2-
amd)
3C
u 2(i P
r 2-a
md)
2
Mg(
Bu 2
amd)
2M
g(i P
r 2-a
md)
2M
n(t B
u 2-p
emd)
2N
i(tB
u 2-a
md)
2
high
reac
tivity
to a
mm
onia
=>
nitr
ides
high
reac
tivity
to H
2S =
> su
lfide
sre
activ
e to
hyd
roge
n ga
s H
2=>
met
als
Cu 2
(Pr 2
amd)
2C
u 2(s
Bu 2
-am
d)2
Er(t B
u 2-a
md)
3Fe
(i Pr 2
-am
d)2
(2
) 2Pr
(i Pr 2
-am
d)3
Sc(E
t 2-a
md)
3Sr
(t Bu 2
-am
d)2
Dis
adva
ntag
es:
seve
ral d
iffer
ent l
i gan
ds n
eede
d2
2Fe
(t BuE
t-am
d)2
Ga(
Et2-
amd)
3G
d(i P
r 2-a
md)
3H
f(Mf
d)
Ti(i P
r 2-a
md)
3V(
Et2-
amd)
3V(
i Pr 2
-am
d)3
Y(i P
d)
gso
me
are
solid
s, n
ot li
quid
s
Hf(M
e 2-fm
d)4
Hf(M
e 2-p
md)
4H
f(Me 2
-bm
d)4
La(i P
rfm
d)
Y(i P
r 2-a
md)
3Zn
(i Pr 2
-am
d)2
Zr(M
e 2-fm
d)4
Zr(M
epm
d)
41
La(i P
r 2-fm
d)3
La(t B
u 2fm
d)3
Zr(M
e 2-p
md)
4Zr
(Me 2
-bm
d)4
Am
idin
ate
ALD
Pre
curs
ors
Am
idin
ate
ALD
Pre
curs
ors
118
H2
1314
1516
17H
eLi
Be
BC
NO
FN
eN
aM
g3
45
67
89
1011
12A
lSi
PS
Cl
Ar
KC
aSc
TiV
Cr
Mn
FeC
oN
iC
uZn
Ga
Ge
As
SeB
rK
rR
bSr
YZr
Nb
Mo
TcR
uR
hPd
Ag
Cd
InSn
SbTe
IXe
Cs
Ba
LaH
fTa
WR
eO
sIr
PtA
uH
gTl
PbB
iPo
At
Rn
FrR
aA
cR
fD
bSg
Bh
Hs
Mt
Ds
Rg
Ce
PrN
dPm
SmEu
Gd
TbD
yH
oEr
TmYb
LuTh
PaU
Np
PuA
mC
mB
kC
fEs
FmM
dLr
No
42
Stru
ctur
es o
f Met
al(II
) Ace
tam
idin
ates
tert
-but
yl2
mm
mm
mm
dd
d
bulk
isop
ropy
l 2m
mm
dd
dd
pp
t Bu-
Etm
dd
dp
p
ligand b
n-pr
opyl
2d
Ni
Co
Cr
FeM
gM
nC
aSr
Ba
creasing
Incr
easi
ng s
ize
of m
etal
ato
m
Inc
m =
vol
atile
mon
omer
d =
vola
tile
dim
erp
= no
n-vo
latil
e po
lym
erp
py
43
Stru
ctur
es o
f Met
al(II
I) A
ceta
mid
inat
es
tert
-but
yl2
nm
mm
mm
md
il
d
bulk
isop
ropy
l 2m
mm
mm
mm
rr
rr
d
Et-t B
ur
d
n-pr
opyl
2m
mr
dd
d
ligand b
npr
opyl
2m
mr
dd
d
Et2
rd
Al
Cr
Ga
VTi
Ru
ScLu
ErY
Gd
EuN
dPr
Ce
LaB
i
creasing
Incr
easi
ng s
ize
of m
etal
ato
m
Inc
d=l
ool
atili
t
n =
non-
exis
tent
?r =
mor
e re
activ
e m
onom
er,
reac
ts w
ith
tH
O&
m =
mor
e cr
owde
d,le
ss re
activ
e m
onom
er,
tith
d =v
olat
iledi
mer
44
d=l
ow-v
olat
ility
dim
erw
ater
, H2O
,&am
mon
ia, N
H3
reac
ts w
ithoz
one,
O3
TYPE
S O
F A
LD R
EAC
TIO
NS
ALD
reac
tions
usu
ally
tran
sfer
one
ato
m
from
a s
urfa
ce-b
ound
gro
up to
a v
apor
gro
up, o
rfr
om a
vap
or g
roup
to a
sur
face
-bou
nd g
roup
(the
reve
rse
dire
ctio
n).
The
tran
sfer
red
atom
s ar
e us
ually
hyd
roge
n, o
xyge
n, fl
uorin
e or
chl
orin
e.
Afe
wre
actio
nstr
ansf
era
who
legr
oup
ofat
oms
notj
usta
sing
leat
omA
few
reac
tions
tran
sfer
aw
hole
grou
pof
atom
s,no
tjus
tasi
ngle
atom
. 45
Exa
mpl
es o
f ALD
Rea
ctio
nsw
ater
H-tr
ansf
er re
actio
ns =
> m
etal
oxi
des
ozon
eO
-tran
sfer
reac
tions
=>
met
al o
xide
s
sila
nolH
-tran
sfer
reac
tions
=>
met
al s
ilica
tes
amm
onia
Htr
ansf
erre
actio
ns=>
met
alni
trid
esam
mon
iaH
-tran
sfer
reac
tions
=>m
etal
nitr
ides
H-r
educ
tion
reac
tions
=>
tran
sitio
n m
etal
s
oxyg
enO
-tran
sfer
reac
tions
=>
nobl
e m
etal
s (P
t, R
u, Ir
)
fluor
ide
to s
ilico
n re
actio
ns =
> tu
n gst
en o
r mol
ybde
num
gy
chlo
ride
to tr
ialk
ylsi
lylr
eact
ions
=>
sele
nide
s or
tellu
rides
46
etha
nola
min
eH
-tran
sfer
reac
tions
=>
inco
rpor
ated
org
anic
gro
ups
Oxi
des
by H
ydro
xyl E
xcha
nge
& H
ydro
lysi
sT
tki
(di
thl
id)h
fi
tith
tt
kh
fi
diid
Hf(N
Me 2
) 4+
2 H
2O =
> H
fO2
+ 4
HN
Me 2
Tetr
akis
(dim
ethy
lam
ido)
hafn
ium
reac
ts w
ith w
ater
to m
ake
hafn
ium
diox
ide
HH
NM
e 2M
e 2N
NM
eM
eN
Che
mis
orpt
ion
by h
ydro
gen
tran
sfer
to li
gand
s to
form
dim
ethy
lam
ine
gas:
OH
OH
OO
Hf
++
2 H
NM
e 2M
e 2N
NM
e 2H
fN
Me 2
Me 2
N
Tran
sfer
of h
ydro
gen
from
wat
er to
sur
face
-bou
nd d
imet
hyla
mid
elig
ands
:H
H
OO
Hf
NM
e 2M
e 2N
OO
Hf
OO
+ 2
HN
Me 2
+ 2
HO
H
47
OO
OO
Oxi
des
by O
xida
tion
with
Ozo
neTr
imet
hyla
lum
inum
reac
tsw
ithoz
one
tom
ake
alum
inum
oxid
e:Tr
imet
hyla
lum
inum
reac
tsw
ithoz
one
tom
ake
alum
inum
oxid
e:
(CH
3)3A
l +
O3
=> A
l 2O3
+ C
H4
+ H
2O +
CO
2
OH
OH
OO
Al
+2
HC
H
CH
3
+Al
(CH
)
Hyd
roge
n at
om tr
ansf
er fr
om s
urfa
ce h
ydro
xyl t
o lig
and
to fo
rm m
etha
ne:
OO
OO
+2
HC
H3
+Al
(CH
3)3
Ot
tf
tf
lid
tf
td
bdi
id
HO
CO
+O
AlCH
3
AlOH
Oxy
gen
atom
tran
sfer
to s
urfa
celig
and
tofo
rm w
ater
and
car
bon
diox
ide:
+H
2O+
CO
2+
O3
OO
OO
Wat
erm
ayno
tbe
dete
cted
beca
use
itre
acts
with
othe
rsur
face
CH
grou
ps
48
Wat
erm
ayno
tbe
dete
cted
beca
use
itre
acts
with
othe
rsur
face
CH
3gr
oups
Met
al S
ilica
tes
from
Sila
nol
OH
OH
OO
Hf
NM
e 2M
e 2N
++
2H
NM
e 2H
fN
Me 2
Me 2
N
Hyd
roge
n at
om tr
ansf
er fr
om s
urfa
ce h
ydro
xyls
to d
imet
hyla
mid
elig
ands
:
OO
OO
++
2H
NM
e 2M
e 2N
NM
e 2H
f
Hyd
roge
n at
om tr
ansf
er fr
om s
ilano
lto
surf
ace-
boun
d di
met
hyla
mid
es:
Hf
NM
e 2M
e 2N
Ot B
uB
ut OH
fO
OS
iO
t Bu
But O
yg
y
OO
Hf
HO
OH
Si+
OO
Hf
+ 2
HN
Me 2
Reg
ener
atio
n of
sur
face
hyd
roxy
ls b
y hy
drog
en fr
om te
rtia
ry b
utyl
gro
ups:
OO
Si
OC
(CH
3)3
(H3C
) 3C
O
OO
Si
OH
HO
CH
3
49
OO
Hf
OO
Hf
+ 2
H2C
C
CH
3
Al-d
oped
SiO
2fr
om A
lMe 3
and
(t BuO
) 3Si
OH
=>ve
ryla
rge
grow
thpe
rcyc
leup
to15
nm>
50m
onol
ayer
s=>
very
larg
egr
owth
perc
ycle
,up
to15
nm,>
50m
onol
ayer
s
Hyd
roge
n at
om tr
ansf
er fr
om s
urfa
ce h
ydro
xyl t
o m
ethy
l lig
ands
:
HH
+(C
H3)
3Al
AlCH
3
+2
HC
H3
OO
(CH
3)3A
lO
O2
HC
H3
SiB
ut OO
t Bu
Ot B
uH
ydro
gen
atom
tran
sfer
from
sila
nols
to m
ethy
l lig
ands
:
AlCH
3(t B
uO) 3
SiO
H
+
AlOSi
Bu
OO
Bu
+H
CH
3
50
Al-d
oped
SiO
2fr
om A
lMe 3
and
(t BuO
) 3Si
OH
Rt
di
tif(
t BO
)Si
OH
it
AlO
bd
Rep
eate
din
sert
ions
of(
t BuO
) 3Si
OH
into
an
Al-O
bond
prod
uces
a s
iloxa
ne p
olym
er te
ther
ed to
the
surf
ace:
Si(O
But ) 3
Si(O
But ) 3
But O
OBu
tSi
But O
OBu
t
O
() 3
(But O
) 3Si
SiBu
t OO
But
O
() 3
t
AlO
Si O
OBu
t
HA
lO-B
ut OH
- n B
ut OH
AlO
n+1
n(B
ut O) 3
SiO
H
51
Al-d
oped
SiO
2fr
om A
lMe 3
and
(t BuO
) 3Si
OH
Elim
inat
ion
ofis
obut
ene
by�
hydr
ogen
tran
sfer
:El
imin
atio
nof
isob
uten
eby
�-hy
drog
entr
ansf
er:
Si(O
But ) 3
Si(O
But ) 3
Si(O
But ) 3
SiBu
t OO
But
O
SiB
ut OO
O
C(C
H3)
2Si
But O
OH
O
+ H
2C=C
(CH
3)2
AlO
AlO
CH
2H
AlO
52
Al-d
oped
SiO
2fr
om A
lMe 3
and
(t BuO
) 3Si
OH
Silo
xane
poly
mer
chai
nscr
oss
link
byel
imin
atio
nof
tert
buta
nol:
Silo
xane
poly
mer
chai
nscr
oss-
link
byel
imin
atio
nof
tert
-but
anol
:
Si(O
But ) 3
Si(O
But ) 3
But
Si(O
But ) 3
Si(O
But ) 3
SiB
ut O
O
SiO
But
OO
OHBu
SiB
ut O
O
SiO
OB
utO
BuO
H
AlO
AlO
AlO
AlO
-BuO
H
Com
plet
e cr
ossl
inki
ng p
rodu
ces
a so
lid s
ilica
laye
r tha
t is
impe
rvio
us to
di
ffusi
on o
f mor
e si
lano
l up
to th
e al
umin
um c
atal
yst,
so re
actio
n st
ops.
py
,p
53
Al-d
oped
SiO
2fr
om A
lMe 3
and
(t BuO
) 3Si
OH
Elim
inat
ion
ofw
ater
also
cros
s-lin
kspo
lym
erch
ains
:El
imin
atio
nof
wat
eral
socr
oss
links
poly
mer
chai
ns:
OSi(O
But ) 3
OSi(O
But ) 3
HOSi
(OB
ut ) 3
OSi(O
But ) 3
OSiB
ut O
O
OSiO
But
OO
OH
OSiB
ut O
O
OSiO
OB
utO
- H2O
Cl
tli
kid
lidili
lth
tii
it
Al
Al
Al
Al
Com
plet
e cr
ossl
inki
ng p
rodu
ces
a so
lid s
ilica
laye
rtha
tis
impe
rvio
usto
diffu
sion
of m
ore
sila
nol u
p to
the
alum
inum
cat
alys
t, so
reac
tion
stop
s. 54
Nitr
ides
by
Chl
orid
e E
xcha
nge
and
Red
uctio
nTi
tani
um(IV
)tet
rach
lorid
epl
usam
mon
iam
akes
titan
ium
(III)
nitr
ide:
Hyd
roge
nat
omtr
ansf
erfr
omsu
rfac
eam
ides
toch
lorid
eson
prec
urso
r:
Tita
nium
(IV)t
etra
chlo
ride
plus
amm
onia
mak
estit
aniu
m(II
I)ni
trid
e:Ti
Cl 4
+ N
H3
=> T
iN
Hyd
roge
nat
omtr
ansf
erfr
omsu
rfac
eam
ides
toch
lorid
eson
prec
urso
r:
NH
NH
NN
TiC
lC
l
++
2 H
Cl
Cl
Cl
TiC
lC
l
Hyd
roge
n at
om tr
ansf
er fr
om a
mm
onia
to s
urfa
ce-b
ound
chl
orid
e lig
ands
:
Cl
Cl
Cl
Cl
NH
HN
NN
TiC
lC
l
+ 2
HC
l+
2 H
NH
2N
NTi
NH
2H
2N
Tita
nium
in o
xida
tion
stat
e +4
is re
duce
d to
+3
by e
limin
atio
n re
actio
ns:
TiN
H2
H2N
TiNH
2
55
NN
TiN
NTi
+ ?
N2,
H2,
and
/or N
2H4
?
Tung
sten
Nitr
ide
by E
xcha
nge
and
Cat
alys
isH
ydro
gen
tran
sfer
from
surf
ace
imid
esto
dim
ethy
lam
ides
onpr
ecur
sor:
Nt B
ut B
uNM
e 2N
NM
e 2
WNt B
ut B
uN
Hyd
roge
ntr
ansf
erfr
omsu
rfac
eim
ides
todi
met
hyla
mid
eson
prec
urso
r:
NH
NH
NN
W+
2 M
e 2N
HM
e 2N
NM
e 2
Hyd
roge
n tr
ansf
er to
imid
es fr
om a
mm
onia
or f
rom
tert
-but
yl im
ido
grou
p?H
H
+ 2
Me 3
CN
H2
or M
e 2C
=CH
2N
N
WN
C(C
H3)
3(H
3C) 3
CN
NN
W
NN
+ N
H3
Red
uctiv
e el
imin
atio
n of
nitr
ogen
to re
duce
W(V
I) to
W(II
I)
56
WN
2=>
W
N
+ ½
N2
Met
als
by R
educ
tion
with
H A
tom
sTi
tani
um fr
om ti
tani
um te
trac
hlor
ide
and
hydr
ogen
ato
ms
in a
pla
sma
TiC
l 4+
4 H
=>
Ti
+ 4
HC
l
Cl
Cl
Hyd
roge
n at
oms
on s
urfa
ce tr
ansf
er to
chl
orid
es o
n pr
ecur
sor:
HH
+ 2
HC
l+
TiC
l 4Ti
Cl
Cl
Hyd
roge
n at
oms
from
pla
sma
rem
ove
chlo
rine
as h
ydro
gen
chlo
ride
gas:
+ 4
HTi
HH
+ 2
HC
lTi
Cl
Cl
57
Met
als
by R
educ
tion
with
H2
Mol
ecul
esD
isso
ciat
ive
chem
isor
ptio
n of
cop
per a
mid
inat
e on
a c
oppe
r sur
face
:
R'
Hyd
roge
n tr
ansf
er to
am
idin
ate
ligan
ds to
mak
e co
pper
& a
mid
ine
vapo
r:
Cu
Cu
NR
R'
NR
N
NR
R'
NR
NC
uC
u
NR
R NR
NN
R
R'
NR
N+
HH
+H
2
58
Cu
Cu
Cu
Cu
Cu
Cu
Cu
NR
RN
Cu
Cu
Cu
Cu
Cu
Cu
Cu
Cu
Cu
Cu
Cu
H2
Nob
le M
etal
s by
Oxi
datio
n R
eact
ions
OO
OO
O
Oxy
gen
atom
s ch
emis
orb
on n
oble
met
als
(pla
tinum
, rut
heni
um, e
tc.):
MM
MM
M+
On
MM
MM
M
OO
OO
O
Ads
orbe
dox
ygen
atom
sbu
rnlig
ands
tofo
rmca
rbon
diox
ide
and
wat
er:
MM
MM
M
OO
OO
O+
ML n
MM
MM
M
MM
MM
M+
CO
2 +
H2O
Ads
orbe
dox
ygen
atom
sbu
rnlig
ands
tofo
rmca
rbon
diox
ide
and
wat
er:
MM
MM
MM
MM
MM
59
Tung
sten
Met
al b
y Fl
uorid
e E
xcha
nge
Ove
rall
reac
tion:
WF 6
+ S
i 2H6
=> W
+ 2
SiF
3H +
2 H
2
aF
atom
mov
es fr
om W
F 6va
por t
o lib
erat
e Si
from
sur
face
:
surf
ace-
WSi
F 2H
+ W
FF5
=> s
urfa
ce-W
WF 5
+ S
iFF 2
H
3 F
atom
s m
ove
from
W o
n su
rfac
e to
bre
ak u
p Si
2H6
vapo
r:
surf
ace-
WW
F 2F 3
+ S
i 2H6
=> s
urfa
ce-W
WSi
F 2H
+ S
iF3H
+ 2
H2
Ave
ryco
mpl
exre
actio
n,br
eaki
ng1
Si-S
i,5
W-F
and
4Si
-Hbo
nds
60
Ave
ryco
mpl
exre
actio
n,br
eaki
ng1
SiSi
,5W
Fan
d4
SiH
bond
sw
hile
form
ing
a ne
w W
-Si b
ond,
5 n
ew S
i-F b
onds
and
2 n
ew H
-H b
onds
Tellu
rides
by
Chl
orid
e E
xcha
nge
Rea
ctio
ns
Chl
orin
e at
oms
on s
urfa
ce m
ove
to tr
ialk
ylsi
lylg
roup
s on
tellu
rium
:R
3R
3R
3R
3R
3
GG
GG
G(R
Si)
T
TeTe
TeTe
Te
Si
Si
Si
Si
Si
R3
R3
R3
R3
R3
RSi
Cl
Cl
Cl
Cl
Cl
Cl
Ge
Ge
Ge
Ge
Ge
+(R
3Si) 2
TeG
eG
eG
eG
eG
e+
R3S
iCl
Chl
orin
e at
oms
on g
erm
aniu
m re
mov
e su
rfac
e tr
ialk
ylsi
lylg
roup
s:
Si
Si
Si
Si
Si
R3
R3
R3
R3
R3
GG
GG
G
Cl
Cl
Cl
Cl
Cl
Ge
Ge
Ge
Ge
Ge
TeTe
TeTe
Te
Si
Si
Si
Si
Si
+ G
eCl 2
Ge
Ge
Ge
Ge
Ge
TeTe
TeTe
Te
Ge
Ge
Ge
Ge
Ge
+ R
3SiC
l
61
Ge
Ge
Ge
Ge
Ge
Ge
Ge
Ge
Ge
Ge
Add
ing
Org
anic
Com
pone
nts
to A
LD F
ilms
A) t
rimet
hyla
lum
inum
)y
B) e
than
olam
ine
C) m
alei
c an
hydr
ide
Add
s fle
xibi
lity
to
britt
lein
orga
nic
film
sbr
ittle
inor
gani
cfil
ms
62fro
m S
. M. G
eorg
e, C
hem
. Rev
. 110
, 111
(201
0)
Pro
blem
s W
hen
the
Che
mis
try is
Wro
ngTh
erm
al d
ecom
posi
tion
dest
roys
the
self-
limiti
ng p
rope
rty
of s
urfa
ce re
actio
nsth
ickn
ess
unifo
rmity
step
cove
rage
and
film
purit
yde
grad
edth
ickn
ess
unifo
rmity
,ste
pco
vera
gean
dfil
mpu
rity
degr
aded
Inco
mpl
ete
surf
ace
reac
tions
can
inco
rpor
ate
ligan
ds a
s im
purit
ies
lki
tib
lli
td
bl
tisl
owki
netic
s ca
n be
alle
viat
edby
long
er e
xpos
ure
times
, or
too
low
ther
mod
ynam
ic d
rivin
g fo
rce
=> c
hang
e pr
ecur
sors
Inco
mpl
ete
step
cov
erag
ene
ed lo
nger
exp
osur
e tim
e or
hig
her p
recu
rsor
vap
or p
ress
ure
but m
ay b
e lim
ited
by d
ecom
posi
tion
or d
esor
ptio
n of
pre
curs
or
Etch
ing
by p
recu
rsor
or r
eact
ion
bypr
oduc
tsm
ostly
from
hal
ide
prec
urso
rs (c
hlor
ides
, bro
mid
es)
63
Sum
mar
yA
LDpr
ecur
sors
are
avai
labl
efo
rmos
tnon
-rad
ioac
tive
elem
ents
ALD
prec
urso
rsar
eav
aila
ble
form
ostn
onra
dioa
ctiv
eel
emen
ts
Suita
ble
reac
tant
pai
rs a
re k
now
n fo
r ALD
of
p
som
e pu
re e
lem
ents
oxid
es o
f mos
t ele
men
ts
nitr
ides
of m
any
elem
ents
sulfi
des,
sel
enid
es a
nd te
llurid
esof
som
e el
emen
ts
phos
phid
es a
nd a
rsen
ides
of a
few
ele
men
ts
fluor
ides
of a
few
ele
men
ts
ALD
reac
tions
usu
ally
invo
lve
exch
ange
reac
tions
betw
een
surf
ace
grou
psan
d va
porg
roup
s
64
ec
age
eact
os
bet
eesu
ace
gou
psa
dap
og
oups
exch
ange
d at
oms
are
usua
lly h
ydro
gen,
oxy
gen
or h
alog
en
Sum
mar
yR
ecen
t Rev
iew
s of
ALD
Che
mis
try
R. P
uuru
nen,
J. A
ppl.
Phys
.97,
121
301
(200
5)
J. P
aiva
saar
iet a
l., T
opic
s in
App
l. Ph
ys.1
06, 1
5 (2
007)
MR
itala
and
JN
iinis
toin
Che
mic
alVa
porD
epos
ition
(Roy
alM
.Rita
laan
dJ.
Niin
isto
,in
Che
mic
alVa
porD
epos
ition
(Roy
alSo
ciet
y of
Che
mis
try,
200
9)
S.M
.Geo
rge,
Che
m.R
ev.1
10,1
11(2
010)
S.M
.Geo
rge,
Che
m.R
ev.1
10,1
11(2
010)
S. D
. Elli
ott,
Lang
mui
r26,
917
9 (2
010)
65
Ack
now
ledg
emen
tsTi
ttA
ltYi
LiSt
uden
ts a
nd P
ost-d
ocs
who
wor
ked
on A
LD in
Gor
don’
s La
bTi
ttaA
alto
nen
Sean
Bar
ryJi
ll B
ecke
rM
ike
Cou
lter
Yiqu
nLi
uH
isas
hi N
akag
awa
Jun
Ni
Daw
enPa
ngM
ike
Cou
lter
Dam
on F
arm
erD
enni
s H
ausm
ann
Ada
mH
ock
Daw
enPa
ngJi
n-Se
ong
Park
Ant
ti R
ahtu
P.Ve
nkat
esw
ara
Rao
Ada
mH
ock
Jaey
eong
Heo
Dae
won
Hon
gEs
ther
Kim
P.Ve
nkat
esw
ara
Rao
Leo
Rod
rigue
zPh
ilipp
e de
Rou
ffign
acPr
aser
t Sin
serm
suks
akul
Kyo
ung-
ha K
imJe
an S
ebas
tien
Lehn
Boo
yong
S. L
im
Am
ethy
st S
mith
Se
igi S
uhH
ongt
ao W
ang
Don
Keu
nLe
eH
uazh
i Li
Zhen
gwen
Li
Xiny
eLi
u
Shen
glon
g W
ang
Xinw
ei W
ang
Shen
g Xu
And
reP
Yose
f
66
Xiny
eLi
uA
ndre
wP.
Yous
efSu
ppor
ted
by th
e U
S N
atio
nal S
cien
ce F
ound
atio
n, D
ow, I
BM
and
Inte
l
