Decorative vacuum coating technologies Certottica Longarone. Thin Film Plasma Coating Technologies

Transcription

1 Dr. Stefan Schlichtherle Dr. Georg Strauss PhysTech Coating Technology GmbH Decorative vacuum coating technologies Certottica Longarone Thin Film Plasma Coating Technologies

2 Content The fascination of functional surfaces produced by thin film technology Presentation of PhysTech Typical applications and examples Functional surfaces PVD (Physical Vapour Deposition) technology Some realised examples

3 PhysTech

4 Thin Film Technology Functionalising of surfaces by PVD technologies Thin films produced by PVD technologies can show a lot of specific properties from nm to µm they make tools hard and wear resistant they transmit, reflect or filter light they protect and decorate surfaces they isolate against heat or coldness they improve electric conductivity they realise diffusion barriers

5 Thin Film Technology Tribology Optics Surface protection Tools Medical Implantats Electronics...

6 PVD technology Coating material transfer mechanisms Three fundamental mechanisms Evaporation Sputtering Exploding Plasma Ablation E-gun for evaporation magnetron plasma arc source deposition

7 PVD technology Evaporation Sputtering - Ablation working gas, e.g. Ar Transport of particles in the plasma electrons Ions +/- Condensation Bias atoms molecules Starting material: Targets, cathodes, granulate, ingots, tabs radicals Gas phase: Plasma reactive gas, e.g. O 2, N 2 Substrate: Glass, metal, plastic

8 PVD technology solid liquid gaseous plasma energy/temperature gas molecules gas molecules excited Ions molecule fragments highly excited free electrons

9 PVD technology Different plasmas in pvd technologies

10 PVD technology Balzers/Evatec BAP 800 Leybold APS 900/1100 Optical Interference Coatings, N. Kaiser, H.K. Pulker, (Eds.), Springer, 2003

11 PVD technology Balanced magnetron configuration Characteristics of Sputtering Sputter Threshold Sputter Yield Sputter Rate Non reactive reactive process Unbalanced magnetron configuration Sputtering variants dc magnetron sputtering dc pulsed magnetron sputtering rf sputtering dual beam sputtering ion beam sputtering closed field sputtering

12 PVD technology Scematic of a magnetron sputter process

13 PVD technology Different voltage configuration in DC-PMS

14 PVD technology Electrical schematic of a pulse generator AE Pinnacle Plus 5kW: 0-350kHz pulse generator

15 PVD technology 1 substrate holder 2 arc sources - cathodes 3 vacumm pumping system 4 gas inlet system 5 gas inlet system 6 substrates, products

16 PVD technology

17 PVD technology Macroparticle filter, LBNL, Berkeley Particle separation with magnetic systems (Droplets, Makropartikel)

18 PVD process analysis Plasmamonitorsystem PPM421 (Inficon) differential pumped mass spectrometer with additional energy analyser (CMA) detection of ions and neutrals measurement of the ion energy distribution of the relevant process ions detection unit: SEV pressure range: up to 10-1 mbar

19 PVD process analysis Langmuir Probe System (Scientific Instruments) trigger acquisition electronics gabing electronics for boxcar mode (100 khz) an electrical conductable and heatable electrode is inserted into the plasma measurement of the voltagecurrent characteristic and calculation of plasma parameters as particle densities, electrical potentials and ion currents relative simple configuration Plasma langmuir probe Principle setup

20 PVD process analysis Ion energy distribution and degree of ionisation Evaporation: Magnetron Sputtering DC Pulsed Sputtering IBAD DC Pulsed Sputtering PLAD, ARC Source

21 PVD process analysis Surface reactions and bombardement effects energetic particle reflected ions or neutrals secondary electrons sputtered atoms or ions surface adsorbed surface species surface region enhanced surface mobility lattice defects trapping displacement enhanced chemical reactions redeposited implanted channeling collision cascade backsputtered surface near surface region Schematic of energetic particles, which bombard the growing film (bombardement) Surface: Interface between solid material and gas (vapour or vacuum) Surface region: depth of penetration of the bombarding particles Near surface region: region below depth of penetration, but is also influenced by e.g. Heating or diffusion Bulk region: region were the material is not influenced by the bombarding effects

22 PVD process analysis Surface reactions and bombardement effects The effects of bombardment of energetic species (ions, neutrals) on the surface and the surface region include: desorption of weakly bonded surface species ejection of secondary electrons reflection of the energetic species as high energetic neutrals sputter ejection of surface atoms by momentum transfer through collision cascades sputtering and re-deposition of sputtered species enhanced mobility of surface atoms enhanced chemical reaction of impinging and adsorbed species. In the subsurface region the impinging particles may be physically implanted the collision cascades cause displacement of atoms and the creation of lattice defects surface species may be recoil-implanted into the surface lattice mobile species may be trapped at lattice defects particle kinetic energy is mostly converted into heat

23 PVD process analysis Ti+ ions cps dc Process parameters: kHz Distance to Ti target: 20cm Pulse frequency: 50kHz - 250kHz 100kHz Pulse width: 1296ns 250kHz I=0,5A p 10 4 tot =3,4*10-3 mbar - 5*10-3 mbar P el =67W - 162W Ar flow =210sccm N flow 2 =30sccm energy in ev Ion energy distribution in a TiN DC-pulsed Magnetron process

24 PVD process analysis 7 10 Ti+ ions Process parameters: I arc =85A Arc target Ti (distance=20cm) P 10 6 N2 variable p tot =1*10-3 mbar p tot =1*10-2 mbar 10 5 p tot =1*10-1 mbar cps energy in ev Ion energy distribution in a TiN Arc Source process

25 PVD process analysis Power density on target E kin of particles Beam velocity Deposition rate Current density on substrate e-gun evaporation Reactive Low Voltage Ion Plating Magnetron sputtering Ion beam sputtering Wcm 4 2 met 3 2 Wcmdiel 4 2 > 10 Wcm ev < 0,3 ev ms High High 2 0, 2 1 macm > 10 Wcm ev Medium 2 0,1 macm > 10 Wcm ev ms Low Medium 2 0,5 1 macm Pulsed laser ablation Arc source ablation Wcm ev ms High 2 > 1 macm Wcm ev ms High 2 > 1 macm

26 PVD film growth

27 PVD film properties Einstellung von Schichteigenschaften Stoichiometry Purity Structure Microstructure Homogeneity Isotropy Topography Density Adherence Hardness Abrasion resistance Stress Anforderungen an optische Schichten: Reproduzierbare und stabile Brechungsindexe Geringe optische Verluste Oberflächenschutz vor Flüssigkeiten, Gasen, Festkörperteilchen, Strahlung Abhängigkeit der Dichte abhängigen Eigenschaften von der kinetischen Energie der bombardierenden Teilchen für verschiedene Prozesstechnologien

28 PVD process technologies Correlation: process parameters plasma properties - film properties Process parameter: process pressure, target material, target power density, applied currents and voltages, pulse frequency and duty cycle Plasma properties: Kinetic energy of ions Ion current density Film properties: Density and morphology of films Oxide films for optical applications Nitride films for tribological and tool applications Refractive index Adhesion Mechanical stress Mechanical stress Optical loss Hardness

29 PVD technology Arc Source Deposition (PhysTech)

30 PVD technology Magnetron Sputter Coater (Edwards)

31 PVD technology Gas-Flow-Sputtering (PhysTech)

32 Research activities EMPA Dübendorf (CH) CeTeV Carsoli (I)

33 Research activities IonBond Newcastle (GB)

34 Thank you for your attention

35 Typical applications Activation of plastic parts Magnetron sputter plasma for the deposition of optical thin films HIPIMS High Plasma Impuls Magnetron Sputtering Deposition of tribological and hard coatings Filtered Arc Source Deposition of hard coatings

36 Typical applications Arc Source Deposition Innova - Balzers Tools Tribology Surface protection Corrosion protection by atmospheric plasma deposition Arc Source Plasma atmospheric plasma deposition increases the polarity of the plastic surface increased adhesion Cleaning of metal parts by plasma pre-treatments

37 Typical applications Plasmapolymerisation treatment of temperature sensitive parts and realisation of specific surface properties like anti-finger-printing, easy to clean, anti-adhesion Pulsed magnetron sputtering for architectual glass coating Decorative hard coatings, z.b. TiN, TiAlN, CrN

38 Typical applications Ion beam assisted deposition for deposition of High precision optical interference coatings APS advanced plasma source Deposition of optical multilayer systems

39 Typical applications Plasmanitrieren: Plasma nitriding is a thermo-chemical process to modify surfaces and barrier layers. It is based on the incorporation of nitrogen into the surface of the component. Process gases are: ammonia, nitrogen, methane and hydrogen. Plasma nitriding takes place in a vacuum chamber under ionic gas atmosphere. To produce wear resistant films sometimes a mixed gas atmosphere is used. The quality of the nitrided surface is dependent on the gas mixture, pressure, temperature and process time. Applications: tools, mechanical components, winds, engine parts like crank shafts, camshafts or valves