AL

D A

ug. 0

9, 2

005

Zhen

gwen

Li(

li14@

fas.

harv

ard.

edu)

Roy

G. G

ordo

n (G

ordo

n@ch

emis

try.h

arva

rd.e

du)

Dep

artm

ent o

f Che

mis

try a

nd C

hem

ical

Bio

logy

Har

vard

Uni

vers

ity

Cam

brid

ge, M

assa

chus

etts

021

38

Ato

mic

Lay

er D

epos

ition

of

Cop

per

And

Cop

per

Nitr

ide

Thin

Film

s Fr

om

Co

pp

er(I

) A

mid

inat

eP

recu

rso

rs

AL

D A

ug. 0

9, 2

005

Why

ALD

Cop

per L

ayer

?

SiO

2: L

ow-

Die

lect

ric

Cu:

See

d La

yer

Cop

per i

s re

plac

ing

Alu

min

um a

s th

e st

anda

rd

inte

rcon

nect

met

al in

mic

roel

ectro

nics

:•L

ower

resi

stiv

ity.

•Bet

ter e

lect

rom

igra

tion.

Adv

anta

ge o

f Ato

mic

Lay

er D

epos

ition

•Con

form

al c

oatin

g •B

arrie

r/adh

esio

n/se

ed la

yer t

oget

her

Cop

per

Con

duct

ors

Low

-kD

iele

ctri

c

Poss

ible

sol

utio

n

DE

VIC

E

Cop

per

Plug

s

AL

D A

ug. 0

8, 2

005

Diff

usio

n B

arrie

r

Adhe

sion

Lay

er

SiO

2: L

ow-k

Die

lect

ric

Cop

per S

eed

Laye

r

AL

D A

ug. 0

9, 2

005

ALD

Cop

per(

I) A

mid

inat

ePr

ecur

sors

Adv

anta

ges

of C

u am

idin

ates

as

prec

urso

rs1.

Hig

h vo

latil

ity a

nd lo

w m

eltin

g po

ints

2.

Low

dep

ositi

on te

mpe

ratu

re (1

30-2

50 o C

) 3.

The

rmal

ly s

tabl

e, N

MR

hal

f life

-tim

e ~

30 d

ays

@19

0 o C

4. P

ure

copp

er fi

lms

(< 1

% c

arbo

n or

oxy

gen

impu

rity)

--Zhe

ngw

enLi

; Sea

n B

arry

; Roy

G. G

ordo

n In

org.

Che

m. 2

005,

44,

172

8-17

35

Cop

per(

I) N

,N’-d

isec

-but

ylac

etam

idin

ate

( [C

u(sB

u-M

e-am

d)] 2

)

--55

/0.0

565

[Cu(

n Pr-

Me-

amd)

] 2

3385

/0.1

77[C

u(s B

u-M

e-am

d)] 2

4570

/0.0

514

7[C

u(i P

r-M

e-am

d)] 2

--60

/0.2

513

0-13

4C

u(hf

ac) 2.x

H2O

----

198

(dec

.) C

u(th

d)2

----

430

Cu 3C

l 3

Hal

f life

-tim

e (d

ays,

in C

6D6,

@

1900 C

)

Vap

orPr

essu

re(o C

/Tor

r)

Mel

ting

Poin

t(o C

)

Cop

per

Prec

urso

r

ALD

Cu

Prec

urso

rs

AL

D A

ug. 0

9, 2

005Sa

tura

tion

Gro

wth

of A

LD

Cop

per

with

H2as

the

Red

ucin

g A

gent

Flow

thro

ugh

and

Clo

se V

alve

Flow

thro

ugh

Res

ults

:•G

row

th ra

te d

epen

ds o

n th

e pr

ecur

sor e

xpos

ure

time:

C

lose

val

ve (2

sec

) vs.

Flo

wth

roug

h ( ~

30

ms)

•S

urfa

ce n

ucle

atio

n to

ALD

met

al.

•Sel

f-lim

ited

grow

th a

t hig

h ex

posu

re.

1000

1000

010

0000

1000

000

0.0

0.2

0.4

0.6

0.8

1.0

Growth Rate ( Å/cycle)

Prec

urso

r Exp

osur

e ( T

orr ·

μse

c)1.

01.

52.

02.

53.

03.

54.

04.

55.

05.

50.

00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

Growth Rate (Å/cycle)

H2 e

xpos

ure

( Tor

r ·se

c)

AL

D A

ug. 0

9, 2

005

020

040

060

080

010

00

0

200

400

600

800

1000

thickness (Å)

cycl

esALD

Cu

Gro

wth

Rat

e on

Diff

eren

t Sub

stra

tes

Con

clus

ions

:

•A

LD C

u gr

owth

beh

avio

r is

diffe

rent

on

diffe

rent

sub

stra

tes.

•The

Gro

wth

rate

is g

ener

ally

larg

er o

n ox

ide

surfa

ces

than

on

met

allic

sur

face

.

•The

initi

al n

ucle

atio

n st

age

play

s an

impo

rtant

role

in m

akin

g co

ntin

uous

Cu

film

.

On

Al 2O

3

0.15

~0.5

(fro

m A

l 2O3

curv

e)C

u

0.28

0.40

(30

cycl

es)

Co

0.57

~0.2

0 (3

00 c

ycle

s)R

u

0.28

0.54

(30

cycl

es)

WN

0.19

1.5

(60

cycl

es)

Si3N

4

0.15

1.90

(100

cyc

les)

Al 2O

3/SiO

2

[Cu(

sBu-

Me-

amd)

] 2E

xpos

ure

(Tor

r·s

ec)

Gro

wth

Rat

e (Å

/cyc

le)

Subs

trat

e

On

diffe

rent

sub

stra

tes

AL

D A

ug. 0

9, 2

005Fi

lm q

ualit

y: H

igh

Asp

ect R

atio

coa

ting

and

Low

impu

ritie

s

•AR

= 4

0;

•Uni

form

and

con

form

al

coat

ing;

•m

axim

um a

spec

t rat

io

can

go to

abo

ve 1

50;

•C

arbo

n im

purit

y be

low

R

BS

det

ectio

n lim

it (<

1%

); 0

200

400

600

800

1000

Cha

nnel

0246810 NormalizedYield

0.5

1.0

1.5

Ener

gy(M

eV)

OC

uC

200

250

300

350

400

Cha

nnel

0123456 NormalizedYield

0.4

0.5

0.6

0.7

Ener

gy(M

eV)

AL

D A

ug. 0

9, 2

005

Cry

stal

Str

uctu

re S

tudy

of C

u by

XR

D a

nd T

EM

X-ra

y D

iffra

ctio

n: p

olyc

ryst

allin

e C

uH

igh

Res

olut

ion

TEM

: C

u nu

clei

5 nm

----Z

heng

wen

Li; R

oy G

. Gor

don;

et a

l. E

lect

roch

em. S

olid

-sta

te L

ett.

8(7)

G18

2 (2

005)

AL

D A

ug. 0

9, 2

005

Abo

ve re

sults

use

d H

2as

the

redu

cing

age

nt.

Wha

t will

hap

pen

if N

H3

is th

e re

duci

ng a

gent

?

AL

D A

ug. 0

9, 2

005

020

040

060

080

010

00Ch

anne

l

010203040 NormalizedYield

0.51.0

1.5En

ergy

(MeV

)

Cu3N

_400

0cy_

on_C

arbo

n

CuN

OC

RB

S of

ALD

Cu 3

N U

sing

NH

3as

the

Red

ucin

g A

gent

RB

S S

pect

rum

of t

he C

u 3N

film

on

Car

bon

subs

trate

•The

sim

ulat

ed c

urve

ratio

: Cu

: N =

3:1

.

•No

obvi

ous

Oxy

gen

peak

, be

low

RB

S d

etec

tion

limit,

< 1

%.

•Car

bon

cont

amin

atio

n <

1 %

.

200

220

240

260

280

300

320

340

Chan

nel

0123456 NormalizedYield

0.40

0.45

0.50

0.55

0.60

0.65

Energ

y(M

eV)

NC

AL

D A

ug. 0

9, 2

005

X-ra

y an

alys

is o

f Cop

per n

itrid

e st

ruct

ure

XR

D s

truct

ure

stud

y of

ann

ealin

g te

mpe

ratu

re e

ffect

1620

2428

3236

4044

4852

5660

64

150

Cu (2

00)

Cu

(111

)

Cu 3

N (1

11)

Cu 3

N (2

00)

ann

eal @

2250

C, H

2/He

anne

al @

2000

C, H

2/He

Counts (a. u.)

2 Th

eta

(deg

ree)

as_d

epos

ited

@16

00C

Cu 3

N (1

00)

Con

clus

ion:

•As-

depo

site

d fil

m is

sto

ichi

omet

ricC

u 3N

, ant

i ReO

3st

ruct

ure,

pr

edom

inan

t at (

100)

.

•Ann

eal a

t 200

0 C, t

he fi

lm b

egin

s to

dec

ompo

se to

cop

per.

•At 2

250 C

, the

film

tota

lly c

onve

rted

to c

oppe

r. (fo

r bul

k m

ater

ial,

deco

mpo

sitio

n ~3

000 C

).

•The

den

sity

of t

he a

s-de

posi

ted

film

s is

5.3

0 g/

cm3

(bul

k 5.

84g/

cm3 .

)

X-ra

y R

efle

ctio

n Sp

ectr

um

0.4

0.6

0.8

1.0

1.2

1.4

100

1000

1000

0

1000

00

Counts

2 Th

eta

(deg

ree)

XR

R c

urve

sim

ulat

ion

AL

D A

ug. 0

9, 2

005

02

46

810

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Cu ammount ( x1013 #/cm2 cycle)

Val

ve O

pen

Tim

e (s

ec)

12

34

56

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

Growth rate (A/cycle)

posi

tion(

inch

)

ALD

Gro

wth

Beh

avio

r Cha

ract

eriz

atio

n of

Cu 3

N F

ilm

Vary

ing

valv

e op

en ti

me,

200

0 CVa

ryin

g N

H3

pres

sure

@ 2

000 C

Res

ults

: gro

wth

sat

urat

ed a

t

•Pre

curs

or b

ubbl

er v

alve

ope

n tim

e T v

alve

= ~

4s.

•Uni

form

gro

wth

at d

iffer

ent l

ocat

ions

. •A

mm

onia

am

ount

is in

larg

e ex

cess

.

•Lin

ear g

row

th o

n al

l the

test

ed s

ubst

rate

s, R

u, S

iO2,

Co,

NiS

i, et

. al.

grow

th ra

te 0

.15A

/cyc

le a

t 160

0 C.

Diff

eren

t pos

ition

s at

160

0 C

for 4

000

cycl

es

prec

urso

r 3.2

nm

ole/

cm2 ,

1600

C

010

020

030

040

0

010203040506070

Film Thickness (Á)

cycl

e nu

mbe

r

y =

0.37

7 +

0.15

0x

R2 =

0.9

97

050

100

150

200

250

300

350

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

RBS Cu ( x1E16#/cm2 /400cycle)

NH

3 exp

osur

e ( t

orr·s

ec)

AL

D A

ug. 0

9, 2

005

Tem

pera

ture

Dep

ende

nt G

row

th o

f Cop

per a

nd C

oppe

r Nitr

ide

low

tem

pera

ture

(~13

00C

-190

0 C),

mai

nly

cont

rolle

d by

reac

tivity

of

the

prec

urso

r and

redu

cing

age

nt

med

ium

tem

pera

ture

(~20

00C

-280

0 C),

deso

rptio

npl

ays

a ro

le

high

tem

pera

ture

(>30

00C

), pr

ecur

sor s

tart

s to

dec

ompo

se

120

140

160

180

200

220

240

260

280

300

320

0123456Amount of Cu (x1E16/400cycle)

Dep

ositi

on T

empe

ratu

re (o

C)

-NH

3 -H

2

Sim

ilar p

heno

men

a ha

ppen

ed o

n

•bo

th C

u an

d C

u 3N

dep

ositi

on

•on

all

subs

trate

s te

sted

: SiO

2, S

i 3N4,

Ru,

Co,

Ti,

NiS

i, A

l 2O3.

AL

D A

ug. 0

9, 2

005

AFM

Stu

dy o

f Film

Sur

face

Mor

phol

ogy

(a).

Tdep

=160

0 C,

thic

knes

s 5.

04 n

mR

MS

1.5

17nm

(b).

Tdep

=200

0 C,th

ickn

ess

3.36

nmR

MS

3.0

47nm

(c).

Tdep

=280

0 C, t

hick

ness

4.7

2nm

RM

S 2

1.10

9nm

With

H2,

Cop

per

With

NH

3, C

oppe

r Nitr

ide

(d).

Tdep

=160

0 C, t

hick

ness

6.7

4 nm

RM

S 0

.706

nm(e

). Td

ep=1

800 C

,thic

knes

s 7.

76nm

RM

S 4

.474

nm(f)

. Tde

p=28

00C

, thi

ckne

ss 4

nm

–7.

2nm

, RM

S 1

1.64

7nm

AL

D A

ug. 0

9, 2

005

AFM

Sur

face

Stu

dy o

f Cu 3

N C

onve

rsio

n to

Cu

As_d

epos

ited

Cu3

N @

1600 C

, Th

ickn

ess

6.74

nm, R

MS

0.7

0nm

@22

50 C, C

u 3N

dec

ompo

ses

to C

u.Th

ickn

ess

~4nm

, R

MS

0.9

1nm

ALD

as-

depo

site

d C

u m

ade

@16

00 C, t

hick

ness

5.0

nm

, RM

S 1

.5 n

m.

•Sm

ooth

Cu

seed

laye

r mad

e fr

om th

e co

nver

sion

of C

u 3N

is p

ossi

ble

RTA

5 m

ins

in H

2/He

AL

D A

ug. 0

9, 2

005

Elec

tric

al p

rope

rtie

s of

Cu

Thin

Film

s fr

om C

u 3N

Con

vers

ion

--a.

Ros

snag

el, S

.; K

uan,

T.;

J. V

ac. S

ci. T

ech.

B22

(1) 2

40 (2

004)

Gra

in B

ound

ary

Scat

terin

g M

odel

si

mul

atio

n eq

uatio

n (a

)

/ 0

= 1+

1.5{

R/(1

-R)}

/ g

Whe

re g

is th

e av

erag

e si

ze o

f the

gr

ains

, =

film

thic

knes

s

R th

e sc

atte

ring

coef

ficie

nt =

0.3

Con

vers

ion

of C

u 3N

to C

u fil

m is

as

good

as

high

vac

uum

spu

ttere

d C

u fil

m

110

051015202530354045 Resistivity ( μohm · cm)

Cu

Thic

knes

s (n

m)

our

dat

a P

VD

Cua

AL

D A

ug. 0

9, 2

005

•A

LD C

oppe

r/cop

per n

itrid

e fil

m w

as m

ade

from

Cu(

I) am

idin

ates

w

ith H

2/NH

3as

redu

cing

age

nt. A

LD b

ehav

ior i

s ca

refu

lly

char

acte

rized

.

•Th

e gr

owth

of A

LD C

u is

sur

face

-dep

ende

nt, w

hile

cop

per n

itrid

e gr

owth

is m

ore

or le

ss s

urfa

ce-in

depe

nden

t.

•B

oth

film

s ar

e pu

re. C

arbo

n an

d ox

ygen

con

tam

inat

ion

< 1

atom

.%.

•A

LD C

oppe

r nitr

ide

is s

moo

ther

than

ALD

cop

per w

ith s

imila

r th

ickn

ess.

Thi

s m

ay b

e us

ed to

mak

e sm

ooth

cop

per f

ilm fr

om

Cop

per n

itrid

e co

nver

sion

.

•C

oppe

r film

is c

ondu

ctiv

e, c

ompa

rabl

e w

ith P

VD

Cu.

AL

D A

ug. 0

9, 2

005

Ack

now

ledg

emen

t

Prof

esso

r Roy

G. G

ordo

n

Seá

nT.

Bar

ryD

amon

B. F

arm

er

Ant

tiR

ahtu

Phi

lippe

de

Rou

ffign

ac

Boo

yong

S. L

imK

evin

Kim

The

Who

le G

ordo

n G

roup

$$: N

SF