© Fraunhofer

PRECISION OPTICAL FILTERS BY EOSS® -

ENHANCED OPTICAL SPUTTERING SYSTEM

© Fraunhofer

Fraunhofer IST, Braunschweig Contact: Dr. M. Vergöhl +49 531 – 2155 640

EOSS®

ENHANCED OPTICAL SPUTTERING SYSTEM

© Fraunhofer

EOSS® Coating System for Precision Optical FiltersMotivation

A coating system that …

… offers stable and easy to use processes without complex process control

… combines the advantage of IBS processes (stability & quality) and evaporation (deposition rate & substrate size)

… is build for continued changes of designs to meet customer demands

… offers inherent long term stability

… produces clean and reproducible coatings

© Fraunhofer

EOSS® Coating System Setup

© Fraunhofer

EOSS® Sputter Coating System Key peformance

Processes

MF, RF sputtering, RF-plasma source

CARS, Metamode, reactive

Coating materials:

SiO2, Al2O3, Ta2O2, Nb2O2, TiO2, ZrO2, HfO2, easy to mix materials, metals

Large area, fast rate:

12x200mm substrates

Uniformity within ±0.15%

Deposition rate: ≤ 0,6 nm/s

Fully automatized production control:MOCCA+®, BBM 360-1650nm

© Fraunhofer

EOSS® Coating System High volume coating system

12 carriers on turntable

Substrate cabinet with 60 carriers (200mm diameter)

Base pressure < 2x10-7 mbar

Process temperature ≤ 300°C

Handling and coating fullyautomatized

© Fraunhofer

EOSS® Coating System Improved coatings by applying cylindrical magnetrons

No redeposition zone and no racetrack!

Continuous and uniform erosion of the surface

racetrack

redeposition zone

transition area:source of particles

© Fraunhofer

EOSS® Coating System Very clean process

Processes

#1-#5: Sputter down

#3-#7: Rotatable

#6: EOSS®, SiO2

#7: EOSS®, 14 layer filter

Particle contamination < 10 ppm

© Fraunhofer

EOSS® Coating System Extremely high uniformity

Distribution of material within the direction of rotational motion

Uniformity better than ±0,10 %

780 785 790 795 800 805 810

0,46

0,48

0,50

0,52

0,54 -96 mm -84 mm -72 mm -60 mm -48 mm -36 mm -24 mm -12 mm Zentrum +12 mm +24 mm +36 mm +48 mm +60 mm +72 mm +84 mm +96 mm

trans

mis

sion

[1]

wavelengt [nm]

© Fraunhofer

EOSS® Coating System Extremely high uniformity

Distribution of material perpend. to the direction of rotational motion

Uniformity better than ±0,15 %

780 785 790 795 800 805 810

0,46

0,48

0,50

0,52

0,54

trans

mis

sion

[1]

wavelength [nm]

-96 mm -84 mm -72 mm -60 mm -48 mm -36 mm -24 mm -12 mm Zentrum +12 mm +24 mm +36 mm +48 mm +60 mm +72 mm +84 mm +96 mm

© Fraunhofer

EOSS® Coating ExamplesLongpass filter

40 layer longpass filter withdefined spectral edge

Partial substrate coatingsby handmade masks

400 500 600 700 800

0

20

40

60

80

100

Sample #1 Sample #2 Sample #3 Sample #4 Sample #5 Sample #6 Sample #7 Sample #8

trans

mis

sion

[%]

wavelength [nm]

50% @ 436,5 nm ± 0,3 nmsubstrates masked and positioned by hand

430 435 440 445 450

0

20

40

60

80

100

Sample #1 Sample #2 Sample #3 Sample #4 Sample #5 Sample #6 Sample #7 Sample #8tra

nsm

issi

on [%

]

Wellenlänge [nm]

© Fraunhofer

EOSS® Coating System Notch filter

OD6 notch filter (80 layers)

Broad band transmission

Excellent layer quality

On 200 mm wafer

560 580 600 620 640 660 680 7001E-5

1E-4

1E-3

0,01

0,1

1

10

100

1000

Tran

smis

sion

[%]

Wavelength [nm]

Filter Theory

© Fraunhofer

EOSS® Coating ExamplesFilter for Laser 3D-projection, 60-80 layers

60-80 layer filter

MOCCA+® monitor

20 measurements on a 200mm wafer

© Fraunhofer

EOSS® Coating ExamplesAR Coating (time-controlled)

400 500 600 7000

20

40

60

80

100

Ref

lect

ance

[%]

Wavelength [nm]

Double side coating, 12 layers/side

Spec: R < 0.5% @ 400-700 nm

10 runs, 5 substrates

Time control only

Extremely reproducible

Thinnest layer < 6 nm

r.m.s. thickness error < 0.1 nm

Very low particular contamination 400 500 600 700

0,0

0,2

0,4

0,6

0,8

1,0

1,2

refle

ctan

ce [%

]

wavelength [nm]

Batches #1- #10 (5 double sided coatings)

© Fraunhofer

Specs:

Tavg > 90% 372 – 378 nm

ODavg>5 bei 337-359 nm und 393-415 nm

ODavg>3 bei 212-265 nm und 385-554 nm

Fabricated without test run

No AR on back side

200 300 400 500 6001E-4

1E-3

0,01

0,1

1

10

100

Tran

smis

sion

[%]

Wellenlänge [nm]

Transmission Design Target

EOSS® Coating ExamplesLaser clean-up filter 375 nm

© Fraunhofer

EOSS® Coating ExamplesBandpass filter, wide blocking range

9 substrates with 200 mm diameter each

Double side coating

Spectra shown for

3different batches

3 different carriers

Wavelength position within 0.25% (±0.125%) 400 600 800 1000 1200 1400 1600

0,0

0,2

0,4

0,6

0,8

1,0

Tran

smis

sion

(%)

Wavelength (nm)

© Fraunhofer

EOSS® Coating System Blended layers by co-Sputtering

Due to the layout of the coating system, co-sputtering in every sputtering mode is possible

Virtually free tunable index of refraction between the materials

Production of Rugate layers

Stabilization of critical materials such as TiO2 , HfO2 by doping with SiO2

0 10 20 30 40 50 60 70 80 90 1001,4

1,6

1,8

2,0

2,2

2,4

2,6

refra

ctiv

e in

dex

(=5

50 n

m) [

1]

fraction of SiO2 in TiO2 [%]

n(=550 nm) EG

3,0

3,5

4,0

4,5

5,0

5,5

optic

al b

andg

ap [e

V]

Filters created by mixed oxides presentedat the Optatec 2012 in Frankfurt

© Fraunhofer

EOSS® Coating SystemProducts & Application

Optical filters ranging from single layers up to several hundred layers

Steep edge

Notch, Multinotch

Bandpass

Beam splitters

High/Low reflection

Polarizers

Dielectric-metal-hybrid

Chirped mirrors

Rugate, Material mixtures

Applications

Analytics: e.g. fluorescence microscopy, ramanspectroscopy, biomedicine, solar simulators, …

Laser based systems: e.g. reflectors, chirped mirrors, …

Coatings on sensitive substrates

The system is build for continued changes of designs to meet customer demands

© Fraunhofer

EOSS® Coating SystemFull production automation by MOCCA+®

The MOCCA+® kit includes

19“ system rack

Spectral range 360 – 1650 nm

Accuracy < 0.3 nm (< 0.6 nm IR )

Light source: 50W halogen

Optical fiber system

Fast measurement interval: 1.6 ms

Optilayer adapter

© Fraunhofer

EOSS® Summary

High precision optical coating system based on magnetron sputtering and cylindrical magnetrons

Fully automized

Excellent layer quality

Low absorption and scatter losses

Dense and defect-free layers

Rotatable magnetrons

Excellent long-term stability with rotatable magnetrons

Target lifetime up to 3 months - 24/7 !

Extremely high uniformity, virtually no drift (no racetrack)