Ludvik Martinu and Jolanta E. Klemberg-Sapieha

Functional Coating and Surface Engineering Laboratory – FCSEL-LaRFISEngineering Physics Department

Thin Film Research Center - GCMEcole Polytechnique, Montreal, Quebec, Canada

Plasma enhanced chemical vapor deposition: From laboratory to large scale production

5th Mikkeli International Industrial Coating Seminar – MIICS-5, Mikkeli, March 17, 2010

FCSEL

Acknowledgements

PhD students and post-docs – this work:

A. AmassianM. Azzi

E. BousserS. Guruvenket

S. HassaniP. Jedrzejowski

S. LaroucheR. Vernhes

Research associate:O. Zabieda

Recent publication: L. Martinu, O. Zabieda, J.E. Klemberg-Sapieha: “Plasma-Enhanced Chemical Vapor Deposition of Functional Coatings”, in the “Handbook on Thin Film Deposition Technologies”, P.M. Martin, ed., Elsevier, Amsterdam, 2009, pp. 394-467.

Functional Coating and Functional Coating and Surface Engineering Surface Engineering

Optical

PhotovoltaicsAutomobile Industry

Aerospace /Defense

VLSI

MEMS

Manufacturing

Telecom

Films

Biotechnology

Concept of Functional CoatingsConcept of Functional Coatings

1. Plasma-surface interactions and plasma systems

Film growth in the energetic plasma environment

2. Hard protective PECVD coatingsFrom tribological coatings for aerospace and automobile to biomedical applications

3. Optical and multifuntional coatings

From optical filters to smart windows, displays and solar cells

4. Conclusions and perspectives

Overview

Plasma-surface interactions

1. Ion bombardment effects: Energy per deposited particleEp ~ Ei . Φi / Φn

Ei < 1 keV, IEDF, Φi ion flux, Φn flux of condensing particles, SZM

Control of Ei and Φi / Φn :

- surface biasing- unbalanced magnetrons- gas phase ionization (plasma assistance)- ionization / biasing (PA-EBE, ECR, PECVD, MW/RF)- plasma pulsing (PMS, HIPIMS, p-PECVD)

2. UV and VUV radiation- strong radiation below 200 nm- crosslinking, surface volatilization

A

ADN m

NrΦ

ρ=

B.A. Movchan, A.V. Demchishin, 1969J.A. Thornton, 1974 R. Messier et al, 1984P.J. Kelly, R.D. Arnell, 1998 J. Musil, 1992A. Anders, 2009

Ion bombardment is essential to the optical and functional coatings industry

PVD techniques• Magnetron sputtering (MS), incl. HIPIMS• Ion-assisted deposition (IAD)• Plasma-assisted deposition (e.g. ion plating)

Ion bombardment in deposition processes

Dense films with smooth surfaces

Modified after: Martinu and PoitrasJVST A18 (2000) 2619

φi /φn

φi : ion fluxφn ∝ deposition rate

PVD( ) SiO2(Δ) dielectrics( ) metals( ) semiconductors

PECVD(A) Si3N4:H(B) SiO2:H(C) a-C:H(D) TiO2

Plasma-CVD techniques• PECVD, pulsed plasma – fp, DC• PICVD• pulse-bias PECVD

100 101 102 103 104 10510-4

10-3

10-2

10-1

100

101

I-1 - IBAD-1I-2 - IBAD-2M -MSD -DIBSP -PECVDF -FCAD

DI-2

F

MI-1

P

P

eV/particle

100

10

1No effect

No film

SiO2 Ta2O5

TiO2

Ion/

parti

cle

arriv

al ra

te ra

tio

Ion energy Ei [eV]

J.E. Klemberg-Sapieha et al., Appl. Opt., 2004

J.M.E. Harper et al., 1989

Plasma density, neElectron temperature, Te

Concentration of radicals, nRPlasma potential, Vp

Surface temperature, TSSurface potential, VS

Reaction productsSecondary electronsSputtered atoms

PhotonsRadicalsIons 

Film properties

Reactor geometry

Pumping speed and gas flow

Excitation power and frequency

Substrate cooling or heating intensity

Optical

Electrical

Mechanical

Tribological

External parameters Internal parameters

Film composition 

and microstructure 

Reactors Plasma reactions Diagnostics

PECVD Materials  Basic film propertiesFunctional 

characteristics and applications

Plasma deposition processes and systems

RF

B: Downstream (remote) RF inductively coupled plasma reactor

Gas (O2, Ar, …)

RF coil

Precursor gas

Reactor configurations of low-, mid-and radio-frequency PECVD systems

A: Parallel plate plasma reactor

Antenna

M

Quartz windowMW power

Gas shower headMW applicator

Quartz window

Gas (O2, Ar, …)

MWpower

Precursor gas

MW power

Quartz jar

G: Electron cyclotron resonance (ECR)

RF

MW applicator

Quartz window

MW linearantenna array

M

I: Distributed antenna array combined with ECR (DECR)

Reactor configurations of microwave frequencyPECVD systems - different modes of excitation

C: Linear applicator D: Remote MW excitation

E: Horn antenna F: Plasma impulse CVD (PICVD)

H: Dual-mode MW/RF

M

RF

Ar

Precursor gas

HV DC HV

AC

Dielectric

M: Atmospheric pressure plasma

Reactor configurations using different modes of operation

J: Atomic layer deposition

(ALD) or CVD

K: Cascade arc L: Hybrid PECVD/PVD system combining parallelplate RF electrode and magnetron sputtering

104

105

106

107

(b)

(a)

N+

N2+

(d)

N+

104

105

106

107

N+

N2+

N2+

Rel

ativ

e In

tens

ity [c

ount

s / s

]

(e)

N+

N2+

0 5 10 15

104

105

106

107

(c)

N+

N2+

Ion Energy [eV]0 50 100 150 200 250 300

(f)

N2+

RF-powered electrodeGrounded electrode

Ion Energy [eV]

Ion energy distributions in nitrogen plasmas

Pulsed MW in C(PMW = 300 WfP = 1 kHzD = 0.5)

IEDFs of N2+ and N+ ions in HF plasmas in N2 (40 mTorr) in different configurations:

cw-RF/p-MW in H(VB = -150 V PMW = 300 WfP = 1 kHz, D = 0.5)

cw-RF in A(VB = 150V)

cw-MW in CPMW = 300W

cw-RF in A(VB = -150 V)

cw-RF/cw-MW in H(VB = -150 V, PMW = 300 W)

O. Zabeida et al., JAP 2000A. Hallil et al., JVST A 2000

-8 -6 -4 -2 0 2 4 6 80.00.10.20.30.40.50.60.70.80.91.0

Ti Ar Si N O

VB = -600 V,φi/φn ≈ 0.4 R = 0.5 nm/sEmax ≈ 690 eVEm ≈ 270 eV

MC simulation of ballistic transport:- Ions: N2

+, N+, and Ar+

- Neutrals: Ti and N

-8 -6 -4 -2 0 2 4 6 80.00.10.20.30.40.50.60.70.80.91.0

Si O

Depth (nm)

-8 -6 -4 -2 0 2 4 6 80.00.10.20.30.40.50.60.70.80.91.0

Ti Ar Si N O

Depth (nm)

2 nm TiN

5 nm TiN

Case study: Deposition of TiN on c-Si - TRIDYN

Bare substrate

Mol

ar fr

actio

nM

olar

frac

tion

Mol

ar fr

actio

n

A. Amassian et al., JVST A, 2006, JAP 2007

TiNTiSiN c-Si

10 nm

Substrate:c-Si(001)Native oxide < 2 nm

RF Pretreatment:ArVB = -600VP = 50 mtorr15 minutes

Deposit TiSiN/TiN:TiCl4 +N2 + Ar (+ SiH4)VB = -600 VP = 200 mtorrTs = 500oC

And HRTEM experimental evidence

1. Plasma-surface interactions and plasma systems

Film growth in the energetic plasma environment

2. Hard protective PECVD coatingsFrom tribological coatings for aerospace and automobile to biomedical applications

3. Optical and multifuntional coatings

From optical filters to smart windows, displays and solar cells

4. Conclusions and perspectives

Overview

PCHigh speed steel

TiAl6V4SiO2 glass

SiO2 quartzc-Si

SiO2

ITOTiO2

Si3N4

Ta2O5

Al2O3

TiNnc-TiN/SiN

c-BN

SiO2

Nb2O5

Ta2O5

TiO2

SiOxNy

SiN1.3

SiCSiCN

a-C:HTiN

nc-TiN/SiNnc-TiCN/SiCN

CNc-BN

c-BN/NCDNCDpc-D

0 20 40 60 80 100

Superhard

Material

Substrate

HardSoft

PECVD

PVD

Microhardness [GPa]

Microhardness of PECVD coatings

10

20

30

40

50 Young's m

odulus, Er , [G

Pa]

H

Har

dnes

s, H

, [G

Pa]

100

200

300

400nc-TiN/SiN1.3

Er

(a)

0 10 20 30 40 500

400

800

1200

Res

istiv

ity, ρ

, [μΩ

cm]

Concentration of Si, CSi [at. %]

ellipsometry 4 point

(b)

P. Jedrzejowski et al, APL 2006λe = 1–2 nm < particle size = 5–10 nm

TiN-based of nanocomposite films

Ralation between erosion rate and the H3/E2 ratio

H/E ratio (elastic strain to failure)

H3/E2 ratio (resistance to plastic

deformation)

•TiN-based films:and 50μm Al2O3particles at 84 m/s: enhanced erosion resistance is obtained for

• Coating thickness: > 8 μm

• Kc = 5-6 MPa.m1/2

• H3/E2 = 0.5-0.6 GPa

• H/E ≈ 0.15-0.2

0.0 0.2 0.4 0.6 0.8 1.00

4

8

12

16

H3/Er2 [GPa]

Volu

me

rem

oved

, W [1

0-10 x

cm3 ]

S. Hassani et al., Wear 2008

Spherical solid particle

Coating

Substrate

Spherical solid particle

Coating

Substrate

2.3 3.13 1.47 2.5p cW V r ρ E / (K H t )∝

Volume removedErosion rate=Mass of impacting particle

FE modeling:Eroded volume per particle

SS410 TiN nc-TiN/SiN0.00

0.02

0.04

0.06

0.08

Er

osio

n ra

te [m

g/g]

0.0 0.2 0.4 0.6 0.8

0.00

0.02

0.04

0.06

0.08

H3/E2 (GPa)

Mas

s lo

ss (m

g/g)

Erosion rate vs. H3/E2 : experiment

S. Guruvenket et al.,SCT 2009

Erosion conditions (ASTM G-76): Al2O3 particles, 50 μm dia., speed 84 m/s

TiN nc-TiN/a-SiN nc-TiCN/a-SiCN0

4

8

12

Wea

r coe

ffici

ent,

K [

10-6

mm

3 /Nm

]

673 K 773 K

Cf : 0.45

0.45

0.42

0.32 0.21

0.18

0.3 0.4 0.5 0.6 0.7 0.8 0.9

0

2

4

6

8

10

12

Wea

r coe

ffici

ent,

K x

[10-6

mm

3 /Nm

]

H3/Er2 [GPa]

Wear conditions (pin on disk): Alumina ball(6 mm dia), sliding speed 1.8 m/min, load 2 N

Open circuit potential measurements during and after the reciprocal sliding test of SS, SS/N3h/DLC, SS/a-SiNx:H, and SS/a-SiNx:H/DLC(Alumina ball, load: 9N, freq.: 1 Hz)

Tribo-corrosion of DLC-coated stainless steel in the Ringer’s solution

Cathodic polarization curves of bare SS and SS/N3h/DLC and SS/SiN/DLC coating systems

M. Azzi et al., Wear 2009

Industrial deposition system for the fabrication of DLC coatings for automotiveparts and other applications. Each chamber contains six 1.6 m long electrodes. (Courtesy of Hauzer Techno Coatings)

Multi-zone PECVD system

Example of a commercial system for the deposition of hard protective coatings: 1.6 m3

volume chambers, metal carbides, nitrides and borides from halide precursors, 1,600 kg of parts coated in one run in high power medium frequency pulsed plasmas (Rubig power supplies)(Courtesy of PATT Technologies Inc., Canada)

PECVD system for hard protective coatings

Lubricious coatingsfor hearing devices

MW ArPrecursor

Custom-fitted and calibrated protective devices

Multiple insertion into the ear

Outcome:• Quantitative tribological testing methodology• Friction reduced by a factor of 10• Production system transferred to Sonomax

0.0 0.5 1.0 1.5 2.0 2.50.0

0.2

0.4

0.6

0.8

1.0

Deposition time [hours]

Fric

tion

coef

ficie

nt, μ 100 mTorr

50 mTorr

1. Plasma-surface interactions and plasma systems

Film growth in the energetic plasma environment

2. Hard protective PECVD coatingsFrom tribological coatings for aerospace and automobile to biomedical applications

3. Optical and multifuntional coatings

From optical filters to smart windows, displays and solar cells

4. Conclusions and perspectives

Overview

SiO2 quartzPMMA

SiO2 glassPC

PET

MgF2

SiO2

Al2O3

Y2O3

ITOZrO2

SiN1.3

Ta2O5

Nb2O5

TiO2

PPFCSiO2:F

SiO2

Al2O3

PPHCPPOSSiOxNy

SiN1.3

SnO2

Ta2O5

SrTiO3

BaTiO3

TiO2:C:HNb2O5

pc-DTiO2

1.4 1.6 1.8 2.0 2.2 2.4 2.6

Material

Substrate

HighMediumLow

PECVD

PVD

Refractive index n @ 550 nm

Refractive index of PECVD coatings

Optical coating systems: From design to manufacture

0 5000 10000

1.6

1.8

2

2.2

Depth (nm)

n

V

RF PLASMA REACTOR

400 600 800 1000 1200 14000.0

0.2

0.4

0.6

0.8

1.0

Wavelength (nm)

T

Design Experimental

Optical filters:1. Targeted performance2. Materials and process3. Design strategy (discrete,

inhomogeneous – graded, quasi-homogeneous)

4. Fabrication + monitoring5. Quality control

OpenFilters: S. Larouche et al, Appl. Opt., 2008S. Larouche et al., Appl. Opt. 2004

Three-band rugate filterTiO2/SiO2

1 10 100

104

105

106N2, 40 mTorr

Rf-poweredelectrodeVb= -150 V

N+

N2+

MW plasma

N+

N2+

Rel

ativ

e In

tens

ity (

Cou

nts

/ s )

Ion Energy ( eV )

n550 ~ 2.0 (RF) n550 ~ 1.6 (MW)

Substrate

n

d

R. Vernhes et al., Appl. Opt. 2004, 2008

Graded layers

Multilayers

Single-material porous/dense optical filters

SiN-based filters, SiH4 + N2 mixtures, reactor HControl strategy: a) substrate bias, b) duty cycle

Electrochromic device - smart windowC.G. Granqvist, Sol. En. Mat. and Solar Cells 2008

Grid

Stainless Steel

n1 Zinc Oxide

Transparent  Electrode (ITO)

i1 a‐SiGe alloy

Silver

p1 n2

p2n3

p3

i2 a‐SiGe alloy

i3 a‐Si alloy

Electron transfer layer (Alq3)

Barrier encapsulation layer

Glass substrate  

Hole transfer layer (NPB)Hole injection layer (CuPc)

Cathode  (‐) (Al/Ag/ITO)

Anode (+) (ITO)

Electron injection layer (Ba/LiF)

Light emitting organic layers  (doped Alq3) ‐ H2O and O2sensitive 

Front Glass Plate

Rear Glass Plate

Ion Storage Layer

Ion Conductor (Electrolyte)

Transparent Conductor (+) 

ElectrochromicLayer

Transparent conductor (‐)

Active thin film devices

Triple-junction solar cellS. Guha, J. Yang, J. Non-Cryst. Sol. 2006

Thin film displayM. Zeuner, Private comm.

Large area (55 cm x 55 cm) MW PECVD coating system – I – barriers, AR coatings (Courtesy of Roth & Rau, Germany)

MW PICVD – commercial reactor for coating individual lamps - FJ. Segner, in “Thin Films for Optical Systems”, F.R. Flory (ed.), Marcel Dekker, NY 1995, p.209Schott Glasswerke

Commercial systems for PECVD optical coatings

Large area roll-to-roll deposition system for the fabrication of triple-junction photovoltaic cells: 2,500m long, 36 cm wide and 125 μm thick SS foils; 4 compartments: a) washing, b) back reflector sputtering (Al, ZnO), c) PECVD of 9-layer triple junction – nc-Si and SiGe, d) AR coating – ITO.System: 90m long, 3m tall, web speed 30 cm/min, 14,5 km of solar cells in 72 hrs.(Courtesy of United Solar Ovonic, USA)

Roll-to-roll PECVD deposition system

Conclusions and perspectives

• PECVD offers a possibility to fabricate films and coatings with a large range of functional properties (n, H, E, …) which are comparable (or better) with respect to their PVD counterparts (H/E, H3/E2, elastic rebound)

• Pulsed high density PECVD processes with pulse-control biasing open new opportunities to tailor the materials and device characteristics

• PECVD is suitable to coat 3D object and achieve high deposition rates (this includes coating internal surfaces)

• Large scale deposition of optical and protective tribological coatings has been demonstrated and is now in production

• PECVD offers new attractive design strategies and coating architectures (graded inhomogeneous coatings, dense/porous systems, nanocomposites, …)

• Work in progress: a) Range of materialsb) Refinement of the film architecturesc) Enhancement of new optical and tribo-corrosion protective systemsd) Design of optical coatings with improved tribo-mechanical properties and of

protective coatings with tailored optical propertiese) Systematic comparison of coatings prepared by p-PECVD, HIPIMS, mod. bias, ...

For more information about our work: www.polymtl.ca/larfis, lmartinu@polytml.ca