An innovative approach to coatings on large optics

Transcription

1 An innovative approach to coatings on large optics OpTIC Strategic Conference 16 th -17 th November 2010 "Photographie: Philippe Bourgeois" CILAS - Établissement Marseille Z.I. St Mitre 15 avenue de la Roche Fourcade Aubagne France - Tel : Fax : Page 1

2 Required Specifications Reflectance and/or transmittance performances Narrow band Filters High reflectance mirrors Environmental conditions, cosmetic, Uniformity requirement over the whole surface of components Master of coating uniformity Spatial repartition of thickness Spatial repartition of refractive index Size of the substrates Page 2

3 Impact of uniformity Depend on the complexity of the optical function Classical antireflection coating u = 5 to 10 % acceptable Metallic mirror u = 10 % acceptable Very narrow band filter u > 1/10 x λ / λc unacceptable => u = 1,5 for λ =10nm at λc =635nm Page 3

4 Parameters to quantify Multilayer stack = alternating different materials => identical coefficient between each thickness = simple shift of the spectral response Uniformity ratio for each material Page 4

5 Production tools 700 m² of clean room ( to 100 class) Industrial coating chambers (in-situ optical monitoring) Dedicated softwares Automated cleaning process Standard and specific metrology Climatic test chambers,. => Applications Defense, Space, Astronomy.. Page 5

6 Stripe filters Integrated on the detector Very narrow band microstructured hyperspectral filters (ASTRIUM, CNES, ESA, ) Lithography using microelectronic technology 80mm x 500µm Transmittance B1 Channel B2 Channel B3 Channel B4 Channel 4 faces-coated stripes wavelength (nm) --> 40 mm x 1mm Page 6

7 Transmission (%) --> Uniformity ratio Coating Uniformity => Shift of the band pass centering Determination of uniformity law 3 nm U = 1, Lambda (nm) --> e M = m. h Page 7 πµ (h 2 +R 2 +ρ 2 ) [1- (2ρR/h 2 +R 2 +ρ 2 )] 3/2 h ρ M R Source

8 Uniformity optimization Uniformity variation (%) Tilt of substrates Uniformity masks Rotation movement 1 Epicycloïd S1 S2 S3 S4 S5Y substrate (mm) S6 S7 S8 S X substrate (mm) 0,150-0,200 0,100-0,150 0,050-0,100 0,000-0,050-0,050-0,000-0,100--0,050-0,150--0,100-0,200--0,150-0,250--0,200-0,300--0,250 Page 8

9 Variation of uniformity versus time Non predictable dynamic errors TRANSMITTANCE --> Theoretical Profile Dynamic errors Ex: Continuous variation of mechanical thickness < 0.3% wavelength (nm) --> Solution : in-situ lateral direct optical monitoring Page 9

10 Reactive Gas Magnetron sputtering DC or RF magnetron Materials targets Ar Plasma Ambient T Vacuum < 10-6 Scrolling of substrates under the targets Substrates Substrates dimensions : L: 2.10 m x l: 2.10 m x h: 40 cm 5 magnetron sources (RF, MF et DC), ie 7 cathodes - metals ( Ag, Al, ) - dielectrics (SiO2, Al2O3, TiO2, Ta2O5, ) in reactive mode Page 10

11 PACA2M : large dimensions Magnetron sputtering 3 mètres Target Substrates during coating High energy technology Dense coatings insensitive to environmental conditions Page 11

12 PACA2M Plateform ** PulvérisAtion CAthodique 2 Meters Dimensions = 11 m x 3.8 m - h = 2,5 m To coat (2 m x 2 m) (height = 40 cm) pieces **Financial support : DGE (FUI), Région PACA, CG13 Partners: Popsud Optitec, Alliance Concept, Institut Fresnel,Thalès Alenia Space Page 12

13 In-situ broad-band optical monitoring** Real-time process monitoring In-situ measurement and follow-up of the spectral profile Process stop when end-layer target spectral profile is reached In-situ determination of indices and thicknesses 9 optical feed through Visible and near infrared optical monitoring Transmittance and/or reflectance ** Collaboration with Fresnel Institute, Marseille Page 13

14 T(λο λο) 1 Transmission 0,8 0,6 0,4 0,2 0 In-situ broad-band optical (ne) (n'e') (n"e") λo/4 2λo/4 λ 0 monitoring «Turning value» optical monitoring (DTE) Automatic errors compensation Essential for narrow band filters monitoring TRANSMITTANCE --> compensated Compensated (10-3) errors compensated Perfect profile (5.10-3) independent Independent (2%) errors wavelength (nm) --> Broad-band optical monitoring Determination of in-situ refractive index (metallic layers) Well-suited to «broad-band» functions λ 20nm Page 14

15 Coating uniformity Dielectric coatings ref PCA041, 042 & mechanical thickness (nm) --> Coordinates (mm) --> 2 meters Page 15

16 Coating uniformity Dielectric coating ref PCA055 20% 15% Uniformity (%) --> 10% 5% 0% % -10% -15% -20% Coordinates (mm) --> Uniformity < 4 % over 2 meters Page 16

17 Coating uniformity Metallic coating ref PCA044 20% 15% Uniformity (%) --> 10% 5% 0% % -10% -15% -20% Coordinates (mm) --> Uniformity < 4 % over 2 meters Page 17

18 Coating uniformity Metallic coating ref PCA045 20% 15% 10% Uniformity (%) --> 5% 0% % -10% -15% -20% Coordinates (mm) --> Uniformity < 5 % over 1.90 meters Page 18

19 Influence of uniformity Metallic coating bulk limited effect Dielectric layers Enhanced reflectivity Protection versus atmospheric conditions master of very thin layers thicknesses => interferential effect Page 19

20 Protected metallic mirrors R --> Influence of uniformity of dielectric layers R(0 ) R(0 ) avec U+10% R(0 ) avec U-10% GABARIT lambda (nm) --> Impact on the lower spectral range Page 20

21 Metal-dielectric absorbers Thin metallic and dielectric layers Broadband optical monitoring Absorbeur Gabarit R --> µm precision lambda (nm) --> Metal-dielectric Reflected light Thickness < 1 µm Metal Dielectric Incident SUBSTRATE Black paint Anodizing Scattered light Thickness µm Incident Absorption SUBSTRATE Page 21

22 Light absorbers Metallic & dielectric materials ref PCA044 & 55 1,08 1,06 dielectric Uniformity (%) --> 1,04 1, ,98 0,96 0,94 0,92 Coordinates (mm) --> metal Page 22

23 Light absorbers 10 9 Position at the center of the tray R --> 4 Matériaux métal & diélectrique ref PCA044 & R < 1% R(0mm) Gabarit 1,08 1, Uniformité (%) --> 0 1, lambda (nm) --> 1, ,98 0,96 0,94 0,92 Coordonnées (mm) --> Page 23

24 Light absorbers 10 9 Position at +375mm 8 7 R < 1% R --> Matériaux métal & diélectrique ref PCA044 & , R(0mm) R(375mm) Gabarit 1,06 1 Uniformité (%) --> 1, ,02 lambda (nm) --> ,98 0,96 0,94 0,92 Coordonnées (mm) --> Page 24

25 Light absorbers 10 Positions at + / - 375mm R --> Matériaux métal & diélectrique ref PCA044 & , R(0mm) R(375mm) R(-375mm) Gabarit 1,06 1 Uniformité (%) --> 1, ,02 lambda (nm) --> ,98 0,96 0,94 0,92 Coordonnées (mm) --> Page 25

26 Positions at + / mm Light absorbers R --> R(-1000mm) R(-750mm) R(-375mm) R(0mm) R(375mm) R(750mm) R(1000mm) Gabarit Matériaux métal & diélectrique ref PCA044 & lambda (nm) --> 1,08 1,06 Uniformité (%) --> 1,04 1, ,98 0,96 0,94 0,92 Coordonnées (mm) --> Page 26

27 Technical results Page 27

28 Protected Silver coatings Production of Laser MegaJoule reflectors for CEA (French Nuclear Agency) Severe environmental specifications : Stainless steel Reflectors before coating Solubility in ethanol and acetic acid Oxidation resistant Temperature : -25 C / + 55 C Solubility in diluted soap in deionized water Resistant to washing machine cleaning Reflectors after Silver coating [ nm] Page 28

29 Enhanced Silver coatings Space mirror for CNES (French Space Agency) Severe environmental specifications Uniformity 100 Measurement over 2 m x 2 m m 104a n 9 104a a a n 6 n 10 n 8 2 m 104a Template 60 n Page 29

30 Enhanced Al Mirror Odeillo Solar furnace refurbishment for DGA (French Defense Agency) Mechanical tests Adhesion, Abrasion Solvents Solubility in DI water (6h) Thermal cycling 24h 40 C - 95%RH Solar flux (2 x 100h) Reflectance (%) --> Protected Aluminum mirror Measurement Theory Template lambda (nm) --> Page 30

31 Enhanced Al Mirror Reflectors for Solar Simulator Lamps for ESA (European Space Agency) Uniformity management Cosmetic requirements Cleaning procedure Spectral performances 700 mm Measurements on different samples along the reflectors ref.104a Reflectance ( %) Lambda en nm Page 31

32 Dielectric coatings Anti-reflection coatings Partial and High Reflective mirrors for Tunable Fabry-Perot, R --> Measurement Theory Gabarit Broadband Antireflection coating lambda (nm) --> Broad-band In-situ Optical Monitoring Coating on large components or great quantity of optical components Page 32

33 Conclusion PACA2M = high performance tool for large coatings In-situ real-time optical monitoring Dense technology Well-adapted for severe environments (Space, Defense, Astronomy, ) Page 33

34 Applications Page 34

35 PACA2M Applications Metallic mirrors Protected and/or enhanced mirrors (Al or Ag) Multidielectric coatings Antireflection coatings All-dielectric mirrors Anti-UV filters Dichroïcs Metal-dielectric coatings Light absorbers Space, astronomy, defense, large scientific instruments Page 35

36 Realizations on PACA2M magnetron sputtering at CILAS Space mirror for CNES (French Space Agency) Metallic mirror on Silicon Carbide Metallic coating on Al mirrors Laser MegaJoule reflectors for CEA (French Nuclear Agency) Solar Furnace refurbishment for DGA (French Defense Agency) Reflectors for ESA Solar Simulator Lamps (European Space Agency) 3DNTT Project with LAM (Marseille Observatory Lab) and for Brazil Observatory.. Page 36

37 Thank you for attention Contact: Catherine Grèzes-Besset, Technical Manager Richard Palomo, Sales Manager Std : +33 (0) Fax : +33 (0) Page 37