ALD

and

CV

D o

f Cop

per-B

ased

Met

alliz

atio

n fo

r M

icro

elec

troni

c Fa

bric

atio

n

Yeu

ngA

u, Y

oubo

Lin,

Hoo

nK

im, Z

heng

wen

Li,

and

Roy

G. G

ordo

nD

epar

tmen

t of C

hem

istry

and

Che

mic

al B

iolo

gyH

arva

rd U

nive

rsity

�Pe

riodi

c im

prov

emen

ts in

per

form

ance

of m

icro

elec

troni

c de

vice

s hav

e be

en a

chie

ved

thro

ugh

devi

ce-s

calin

g

Intro

duct

ion

�C

oppe

r was

sele

cted

bec

ause

of i

ts (1

) abu

ndan

ce, (

2) lo

w

resi

stiv

ity, a

nd (3

) bet

ter e

lect

rom

igra

tion

relia

bilit

y�

Dam

asce

ne p

roce

ss (E

P an

d C

MP)

is c

omm

only

ado

pted

fo

r pat

tern

ing

copp

er

Typi

cal D

amas

cene

Pro

cess

2

Out

line

In to

day’

s pre

sent

atio

n:

�A

LD a

nd C

VD

of C

u fil

ms f

rom

a

Cu(

I) a

mid

inat

epr

ecur

sor

�Fo

rmat

ion

of C

u se

ed la

yer b

y A

LD o

f Cu

and

by C

VD

of

CuO

N

�B

otto

m-u

p fil

ling

of C

VD

-Cu

and

CuM

nal

loy

in n

anos

cale

fe

atur

es

�Su

mm

ary

3

Cro

ss-S

ectio

n of

Mic

ropr

oces

sors

�R

equi

rem

ents

for g

ood

ALD

Cu

prec

urso

rs: (

1) th

erm

ally

stab

le, (

2) v

olat

ile, a

nd (3

) m

inim

al c

onta

min

atio

ns

Cop

per P

recu

rsor

s4

Copp

er (I

) N,N

'-di-s

ec-

buty

lace

tam

idin

ate

Mel

ting

Poin

t: ~

75C

Bub

bler

Tem

pera

ture

:130

CVa

por

Pres

sure

: ~0.

25 m

bar a

t 95

C

CuNN

N CuN

Adv

anta

ges o

fmet

al a

mid

inat

espr

ecur

sors

:�

Bid

enta

tech

ealti

ngef

fect

enh

ance

s the

rmal

stab

ility

�Tu

nabl

e re

activ

ity a

nd v

olat

ility

�M

inim

al c

arbo

nan

d ox

ygen

con

tam

inat

ion

B. S

. Lim

, A. R

ahtu

, J. S

. Par

k, a

nd R

. G. G

ordo

n, In

org.

Che

m.,

42(2

4), 7

951-

7958

, (20

03).

�C

oppe

r film

s cou

ld b

e de

posi

ted

by A

LD u

sing

mol

ecul

ar h

ydro

gen

as re

duci

ng a

gent

ALD

of C

oppe

r5

Ove

nH

eate

d C

ham

ber

Pum

p

H2

Cu(

I) a

md

�C

oppe

r dep

osite

d on

ALD

-Al 2O

3su

bstra

te a

t low

tem

pera

ture

s (15

0-19

0C

):

Z. L

i, A

. Rah

tu, a

nd R

. G. G

ordo

n, J

. Ele

ctro

chem

. Soc

.,15

3(1

1) C

787-

C79

4 (2

006)

AL

D S

yste

m

ALD

of C

oppe

r6

�G

row

th b

ehav

ior c

an b

e af

fect

ed b

y m

any

fact

ors:

surf

ace

chem

istry

, pre

curs

or

expo

sure

, dep

ositi

on te

mpe

ratu

re, e

tc.

AL

D-A

l 2O3,

AL

D-H

fO2,

The

rmal

SiO

2In

itial

ly ~

2Å/c

ycle

, ~0.

5Å/c

ycle

whe

n su

rfac

e is

fully

cov

ered

by

Cu

Ru

Subs

trat

es0.

11Å

/cyc

le

�A

LD h

as th

e ab

ility

to g

row

film

s con

form

ally

and

unifo

rmly

ove

r hig

h as

pect

ratio

ho

les a

nd tr

ench

es

Cop

per S

eed

Laye

r Usi

ng A

LD7

Z. L

i, R

. G. G

ordo

n, D

. F. F

arm

er, Y

. Lin

, and

J. V

lass

ak, E

lect

roch

em. S

olid

-Sta

te L

ett.,

8(7

) G18

2-G

185

(200

5)

AL

D C

u in

AR

= 3

5:1

Hol

es

�Fo

ur-p

oint

ben

d ex

perim

ent s

how

ed h

igh

adhe

sion

ene

rgie

s for

Cu/

Co/

WN

/SiO

2

In-s

ituR

esis

tanc

e M

easu

rem

ent

ALD

Cu

on G

lass

(185

C)

�C

oppe

r see

d la

yers

mus

t hav

e co

nfor

mal

step

cov

erag

e, st

rong

adh

esio

n an

d sm

ooth

su

rfac

e m

orph

olog

y

Cu

Seed

Lay

er U

sing

CV

D-C

uON

and

Plas

ma

Red

uctio

n8

H. K

im, H

. B. B

hand

ari,

S. X

u, a

nd R

.G. G

ordo

n, J

. Ele

ctro

chem

. Soc

., 15

5(7

) H

494-

H50

3 (2

008)

.

Taun

derl

ayer

100n

m

1μm

100n

m

Ru

unde

rlay

er

�Is

land

gro

wth

of C

VD

-Cu

on T

a un

derla

yer

�C

u ha

s fai

rly h

igh

wet

tabi

lity

on R

u, b

ut re

quire

s >20

nm to

form

a c

ontin

uous

film

due

to

isla

nd g

row

th

�N

ew a

ppro

ach:

Cu

prec

urso

r + H

2O�

Cu 2

OC

u pr

ecur

sor +

NH

3�

Cu 3

NC

u pr

ecur

sor

+ H

2O +

NH

3�

CuO

N

Low

Sur

face

Ene

rgy

(22-

26 m

J/m

2fo

r Cu 2

Oan

d C

u 3N

, com

pare

d to

170

0-19

00 m

J/m

2fo

r Cu)

Rem

ote

Hyd

roge

n Pl

asm

a R

educ

tion

near

RT

Thi

n (<

10 n

m),

Smoo

th

(RM

S ~1

nm

), H

igh

Den

sity

(95%

) CV

D

Cu

Seed

Lay

er

Thi

n (<

10 n

m),

Smoo

th

(RM

S ~1

nm

), H

igh

Den

sity

(95%

) CV

D

Cu

Seed

Lay

er

SiSiO

2

Ru

Ta/T

aN

Cu

Seed

Lay

er U

sing

CV

D-C

uON

and

Plas

ma

Red

uctio

n9

Ove

n

Hea

ted

Cha

mbe

r

Pum

p

H2

NH

3

N2

H2O

Cu(

I) a

md

CV

D S

yste

m

Tem

pera

ture

: 140

-220

°CPr

essu

re: 8

Tor

r

Rem

ote

Plas

ma

Gen

erat

or

Pum

p

Ar

H2

Plas

ma

Syst

em

Tem

pera

ture

: RT

-50°

CR

educ

tion

Tim

e: 3

0-18

0s0%20%

40%

60%

80%

100%

140

180

220

N O Cu

Com

posi

tion

of C

VD

-CuO

NFi

lms

(H2O

:NH

3=30

:10)

Cu

Seed

Lay

er U

sing

CV

D-C

uON

and

Plas

ma

Red

uctio

n10

Surf

ace

Mor

phol

ogy

of 2

0nm

of C

VD

-CuO

NFi

lms

(H2O

:NH

3=30

:10)

100

nm

Step

Cov

erag

e in

Hig

h A

R H

oles

(H2O

:NH

3=30

:10,

140

C)

140

C, 0

.64

nm16

0C

, 0.5

4 nm

180

C, 0

.72

nm22

0C

, 1.0

4 nm

Filli

ng N

arro

w F

eatu

res w

ith C

VD

of C

oppe

r�

Con

vent

iona

l tec

hniq

ues l

ead

to fo

rmat

ion

of v

oids

and

seam

s in

very

nar

row

feat

ures

�Io

dine

is a

cat

alyt

ic su

rfac

tant

that

pro

mot

es sm

ooth

er m

orph

olog

y an

d hi

gher

dep

osit

rate

�B

otto

m-u

p fil

ling

of su

b-m

icro

met

er fe

atur

es c

ould

be

achi

eved

by

CV

D

E. S

. Hw

ang

and

J. Le

e, C

hem

. Mat

er.,1

2, 2

076

(200

0).

K. S

him

, O. K

won

, H. P

ark,

W. K

oh, a

nd S

. Kan

g, J

. Ele

ctro

chem

. Soc

.,14

9(2

) G10

9-G

113

(200

2).

�Th

is p

roce

ss re

quire

s a c

onfo

rmal

Cu

seed

laye

r on

top

of th

e di

ffusi

on b

arrie

r and

ad

hesi

on la

yer

11

Surf

acta

nt C

atal

yzed

CV

D C

u an

d C

uMn

in N

arro

w T

renc

hes

Key

Poi

nts

�C

onfo

rmal

lyde

posi

ted

man

gane

se n

itrid

e se

rves

as

a b

arrie

r/adh

esio

n la

yer

�Io

dine

act

s as a

surf

acta

nt c

atal

yst t

o pr

omot

e C

u an

d M

ngr

owth

�Vo

id-f

ree,

bot

tom

-up

fillin

g of

Cu

or C

u-M

nal

loy

in n

arro

w tr

ench

es w

ith A

R u

p to

at l

east

5:1

�M

ndi

ffuse

s out

from

Cu

durin

g po

st-a

nnea

ling

to

furth

er im

prov

es a

dhes

ion

and

barr

ier p

rope

rties

at

Cu/

insu

lato

r int

erfa

ce

Mot

ivat

ion

Cu

Cu/

Mn

Cu/

Mn

Die

lect

ricsC

appi

ng L

ayer

Y. A

u, Y

. Lin

and

R. G

. Gor

don,

J. E

lect

roch

em. S

oc.,

158

(5)

D24

8-D

253

(201

1).

12

Che

mic

al V

apor

Dep

ositi

on o

f Cop

per

Prec

urso

rs

Copp

er (I

) N,N

'-di-s

ec-

buty

lace

tam

idin

ate

Mel

ting

Poin

t: ~

75°C

Bub

bler

Tem

pera

ture

:130

°CVa

por

Pres

sure

: ~0.

25 m

bar a

t 95°

C

CuNN

N CuN

CV

D S

yste

m

Tem

pera

ture

130°

C fo

r Mn 4

N18

0°C

for C

u an

d C

uMn

Pres

sure

: 5 T

orr

Bis

(N,N

'-di

isopr

opyl

pent

ylam

idin

ato)

man

gane

se(I

I)M

eltin

g Po

int:

~60

°CB

ubbl

er T

empe

ratu

re:9

0°C

Vapo

r Pr

essu

re: ~

0.1

mba

r at 9

0°C

NNN N

Mn

Ove

n

Hea

ted

Cha

mbe

r

Pum

p

H2

NH

3

N2

CH

3CH

2I

13

CV

D-M

n 4N

Bar

rier/A

dhes

ion

Laye

r�

CV

D-M

n 4N

(εph

ase,

FC

C st

ruct

ure)

can

be

prep

ared

by

reac

ting

man

gane

se a

mid

inat

epr

ecur

sors

with

NH

3

Die

lect

rics

CV

D-M

n 4N

RM

S ro

ughn

ess =

0.9

7 nm

for a

13.

5 nm

film

Exce

llent

step

cov

erag

e ho

les w

ith A

R =

52:

1

14

�M

n 4N

laye

r as t

hin

as 2

.5 n

m (1

) sho

ws b

arrie

r pro

perti

es a

gain

st C

u di

ffusi

on, (

2)

sign

ifica

ntly

impr

ove

adhe

sion

(deb

ondi

ng e

nerg

y =

6.5

J/m

2 ) b

etw

een

Cu

and

SiO

2

�R

elea

se o

f iod

ine

and

cata

lytic

effe

cts a

re o

bser

ved

on M

n 4N

unde

rlaye

r

Iodi

neEx

posu

reC

VD

-Cu

Dep

ositi

onC

VD

-Mn 4

ND

epos

ition

Surf

acta

nt C

atal

yzed

Bot

tom

-up

Filli

ng o

f CV

D-C

u

With

CV

D-M

n 4N

line

r la

yer

and

iodi

ne c

atal

yst,

tren

ches

with

wid

th �

20

nm a

nd a

spec

t rat

io o

ver

5:1

can

be c

ompl

etel

y fil

led

with

CV

D-C

u

15

Cu

Die

lect

rics

18 n

m S

truc

ture

26 n

m S

truc

ture

Cu

Surf

acta

nt C

atal

yzed

Bot

tom

-up

Filli

ng o

f CV

D-C

uMn

Allo

y

Cu-

Mn

Cu-

Mn

Die

lect

ricsC

appi

ng L

ayer

CV

D-M

n 4N

Dep

ositi

onIo

dine

Exp

osur

eC

VD

-CuM

nA

lloy

�C

u-M

nal

loy

can

be fo

rmed

by

(1) a

ltern

atin

g C

VD

-Cu

and

Mn

or (2

) co-

depo

sitin

g C

u an

d M

n

16

Tren

ches

with

wid

th �

30

nm c

an b

e co

mpl

etel

y fil

led

with

CuM

nal

loy

Man

gane

se c

once

ntra

tion:

0.5

-2.0

ato

mic

%

�In

sula

tors

enc

oura

ges d

iffus

ion

of M

nth

roug

h C

u gr

ain

boun

darie

s to

inte

rfac

e�

Mn

impr

oves

bot

h ad

hesi

on a

nd b

arrie

r pro

perti

es a

t the

inte

rfac

e

Enha

ncem

ent b

y D

iffus

ion

of M

nfr

om C

u to

Inte

rfac

e17

0246810121416

00.

10.

20.

30.

40.

50.

60.

7

Adhesion Energy(J/m2)

Mn/

Si R

atio

from

XPS

Inte

grat

ion

Si3N

4/C

uSi

O2/

Cu

Y. A

u, Y

. Lin

, H. K

im, E

. Beh

, Y. L

iu a

nd R

. G. G

ordo

n, J.

Ele

ctro

chem

. Soc

.,15

7(6

) D34

1-D

345

(201

0).

Sum

mar

y

�C

oppe

r can

be

depo

site

d by

ALD

or C

VD

usi

ng a

Cu(

I) a

mid

inat

epr

ecur

sor

�C

onfo

rmal

and

uni

form

seed

laye

rs c

an b

e pr

epar

ed b

y A

LD-C

u or

by

CV

D-C

uON

follo

wed

by

rem

ote

hydr

ogen

pla

sma

redu

ctio

n

�N

anos

cale

tren

ches

can

be

supe

rcon

form

ally

fille

d by

CV

D-C

u an

d C

VD

-CuM

nal

loy

with

an

iodi

ne su

rfac

tant

on

Mn 4

N li

ner l

ayer

�M

anga

nese

in C

u-M

nal

loy

diffu

ses o

ut to

stre

ngth

en th

e in

terf

ace

betw

een

Cu

and

insu

lato

rs w

ithou

t inc

reas

ing

the

resi

stiv

ity o

f Cu

�M

anga

nese

silic

ate

(MnS

i xOy)

inte

rfac

ial l

ayer

show

s exc

elle

nt b

arrie

r pr

oper

ties a

gain

st C

u di

ffusi

on a

nd p

rote

cts C

u fr

om c

orro

sion

by

H2O

and

O2

18

Ack

now

ledg

emen

ts�

Faci

litie

s at H

arva

rd’s

Cen

ter f

or N

anos

cale

Syst

ems (

CN

S), a

mem

ber o

f the

Nat

iona

l N

anot

echn

olog

y In

fras

truct

ure

Net

wor

k (N

NIN

), su

ppor

ted

by th

e N

atio

nal S

cien

ce

Foun

datio

n

�Pr

ecur

sors

: Dow

Che

mic

al C

ompa

nySu

bstra

tes a

nd A

naly

ses:

App

lied

Mat

eria

ls, I

MEC

and

IBM

�M

embe

rs o

f Gor

don

Gro

up

19