High Rate low pressure PECVD for barrier and optical coatings€¦ · 11-13 June | Prague, Czech...

© Fraunhofer FEP

Steffen Günther, M atthias Fahland, John Fahlteich, Björn M eyer, Steffen Straach, Nicolas Schiller

High Rate low pressure PECVD for barrier and opt ical coat ings

© Fraunhofer FEP

Out line

Introduction PECV D

New developments

magPECV D

arcPECV D

Examples

Optics

Barrier

Outlook

© Fraunhofer FEP

A IM CA L Europe W eb Coating Conference 2012 11-13 June | Prague, Czech Republic

High rate low pressure PECVD Steffen Günther 3

Plasma enhanced CVD – PECVD?

CV D – chemical vapor deposition

Layer growth by chemical reaction at surface

Layer material delivered by chemical compound precursor

Energy transforms precursor into reactive species

Plasma energy is used within PECV D

Several by-products

H2O

CO2

other low-molecular compounds

A dditional reactive gas suppliable

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Why PECVD?

Low temperature process

Use of sensitive substrates like polymers

Performs in vacuum

Clean environment

Broad choice of pre cursors and reactive gases

W ide range of process parameters

Power

Frequency

Pressure

. . .

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Out line

Introduction PECV D

New developments

magPECV D

arcPECV D

Examples

Optics

Barrier

Outlook

© Fraunhofer FEP



Magnet ron based PECVD – magPECVD

Low pressure CV D (0.3 – 3 Pa)

Driven by pulsed DC magnetron

High coating rates (up to 400 nm m/min)

Proven long-term stability over 8 h

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magPECVD

W ell-established plasma source

Proven feasibility for large area applications

Tuneable layer composition

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magPECVD DC sput tering

One hardware • dual magnetron • targets • gas inlets

Two processes • magPECVD • reactive DC sputtering

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Hollow -cathode arc PECVD – arcPECVD

Low pressure CV D (0.1 – 5 Pa)

Driven by hollow cathode arc plasma

V ery high coating rates (> 2000 nm m/min)

Tuneable layer composition

Combination with evaporation possible

Organic modif ied coatings

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arcPECVD coat ing rates

Linearly dependent from pre cursor f low

Increase with plasma power

Increase with additional reactive gas f low

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Plasma system for arcPECVD

V ery high plasma density

Commercially available

Designed for production

„ A ny“ web width through numbers of plasma sources

Developed for large area applications

2,85 m

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arcPECVD Plasma enhanced evaporat ion

One hardware • hollow cathodes • gas inlets

Two processes • arcPECVD • Plasma enhanced

reactive evaporation

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Comparison of PECVD methods

magPECV D arcPECV D HF-PECV D M W -PECV D

typical f requency

10-50 kHz bipolar pulsed DC 13.56 M Hz 2.45 GHz

process pressure 0.3 – 3 Pa 0.1 – 5 Pa 1 – 20 Pa 5 – 100 Pa

coating rates

20 – 400 nm m/min

500 – 3000 nm m/min

10 – 200 nm m/min

10 – 100 nm m/min

remarks industrially proven for wide

webs, units commercially available

pressure range different to PV D

Low pressure CV D

Inline combination with PV D possible

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Inline combinat ion of PECVD and PVD

R& D and pilot roll coater at FEP

600 mm coating width

M ulti-chamber design

A vailable processes

Sputtering (planar / rotatable)

magPECV D

Evaporation

arcPECV D

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Out line

Introduction PECV D

New developments

magPECV D

arcPECV D

Examples

Optics

Barrier

Outlook

© Fraunhofer FEP



Layer composit ion

Precursor to reactive gas ratio adjustable

Layer composition tunable

HM DSO ratio low

low carbon content

inorganic SiO2-like layers

HM DSO ratio high

higher carbon content

organic SiOxCyHz layers

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Layer composit ion – mechanical propert ies

Increase HM DSO ratio

Decrease of hardness

Decrease of elastic modulus

Increase in f lexibility

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Opt ical performance

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overall thickness approx. 1400 nm

SiO2 made by

sputtering

magPECV D

Dielect ric solar cont rol layer stacks

9 layers

infrared

visible

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Dielect ric solar cont rol layer stacks

substrate curling due to layer stress

nearly no layer stress

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Dielect ric UV-mirror w ith magPECVD

20 layers

500 nm HfO2 – high refractive index

SiO2 – low refractive index

high UV -ref lectance – high V IS-transmittance

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Dielect ric UV-mirror w ith magPECVD

layer stack out of 20 single layers

overall thickness approx. 1200 nm

highly uniform over 400 mm web width

only 12 nm UV -edge shift across web width

20 layers

Spectra measured across web width

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Permeat ion barrier stacks

Covering of layer defects by upper layers

Surface smoothing

A nnealing of permeation barrier defects

Increase of barrier performance

Increase of mechanical robustness

400 nm

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Permeat ion barrier stacks

Inline made barrier stack

2 m/min web speed

High barrier level comparable to single layers

Improved mechanical robustness

Barrier measurement @ 38 °C, 90 % r.h. Sample size Ø100 mm

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Permeat ion barrier stacks – increased robustness

Barrier layer Zinc-tin-oxid (ZTO)

Interlayer SiO2 made by magPECV D

1 2 3 number of ZTO layers

PECV D interlayers increase crack onset strain

Layer stack more robust against mechanical deformation

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Summary

PECV D within multi-chamber PV D coaters

Low pressure PECV D

Designed for easy scale up

Two options: magPECV D and arcPECV D

One hardware – multiple processes

Optical coating stacks with nearly no layer stress

Permeation barrier stacks with increased mechanical robustness

Further development w ork

Qualif ication for further pre cursors

A daptation to further industrial applications

. . .

Y our application?

W here can we work together?

How can PECV D technology be integrated into your facilities?

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Acknow ledgement

Essential results were obtained in several public projects, funded by Free State of Saxony, Federal M inistry of Education and Research and European Union

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Thank you for your at tent ion

High rate low pressure PECV D for barrier and optical coatings

Steffen Günther Fraunhofer FEP W interbergstr. 28 01277 Dresden Germany

[email protected] www.fep.fraunhofer.de

High Rate low pressure PECVD for barrier and optical coatings€¦ · 11-13 June | Prague, Czech...

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