16 th March 2011
The act of applying a thin film to a surface is thin-film deposition - any technique for depositing a thin film of material onto a substrate or onto previously deposited layers. Thin is a relative term, but most deposition techniques control layer thickness within a few tens of nanometres. Molecular beam epitaxy allows a single layer of atoms to be deposited at a time.
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others Mirrors (metal-coated in first century AD); nowadays - Au, Al with additives as Tin(II) chloride and others; one/two-way mirrors, semitransparent,... Anti-reflective coatings (glasses, telescopes, lenses,...); complex thin film structures with alternating layers of contrasting refractive index (destructive interference); often additional coating repelling water and grease interference layers, polarization layers,... in general any transparent layer
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others transistors, diodes, capacitor, inductors, resistors and conductors and isolators in general CMOS (Complementary Metal-Oxide-Semiconductors) MOSFET (Metal-Oxide-Semiconductor field-effect transistors) Integrated circuit GaAs/Si growth on Si/GaAs, dopants B or P oxides - SiO 2 or nitride - Si 3 N 4
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others MOS and MOSFET
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others implants (hip or other joints replacements) adsorb bandages or yarns, stitches needles, scalpels, tools in general wires, stents eye lenses pills polymer tubes (IV tube,...)
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others Medicine (hip replacement)
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others Medicine (stents)
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others Surface modification: passivation, tribological appl., decorative appl., hydrophobic/hydrophilic appl. Microelectronics: passive (dielectric, resistor, capacitor, conductor,... films), active (thin-film transistors, diodes), interconnections, integrated ciscuits Anti-corrosive layers Optics: anti-reflection, reflection, intereference, polarization,... Sensors: pressure, acceleration, gas,... basic hard layers improving liveability of part including the engine
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others Photovoltaic cells Thin-film batteries Sensors (pressure, gas - toxins, heavy metals, acceleration) Tool manufacturing and coating wrappings
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others Photovoltaics
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others Thin film batteries
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others Sensors
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others Cutting tools (Tribological appl.)
Optical appl. Microelectronics appl. Biomedical appl. Automotive industry Others Coated Al foils, wrapping foils, bottles
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying Vacuum Evaporation reduction of pressure in liquid-filled container liquid evaporation at lower temperature than normal history - process invented by Henri Nestlé in 1866 (condensed milk - water evaporation) as deposition technique for semiconductor, microelectronics and optical industry
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying evaporation by flash, arc (high contamination), laser ablation (clean), exploding wire (only metal films, clean), electron gun (SiO 2 ) can be used in reactive mode (oxides) Advantages and Disadvantages higher deposition rate than or sputtering evaporation has Maxwellian energy distribution given by source temperature, sputtering uses plasma (high-speed atoms - non Maxwellian distribution) Application aluminized PET film, other packing - isolation from water vapour, oxygen or light - often transparent (thin is cheaper than thick opaque) metal films
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying MBE - Molecular Beam Epitaxy low deposition rate (1 µm per hour); monolayer film Knudsen cells (heated to different temperatures) other configurations (ALE - Atomic Line Epitaxy, CBE - Chemical Beam Epitaxy, HWE - Hot wall epitaxy, LPE - Liquid Phase Epitaxy
a) MO, b) MBE c) CBE Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying Cathodic Arc Deposition or Arc- electric arc vaporization of cathode target material condensation on a substrate = formation of thin film technology origin in Soviet Union around 1960-1970 strike of high current, low voltage gives rise to a small cathode spot (highly energetic emitting area), localized temperature around 15000 C high velocity (10 km/s) jet of vapourised cathode material presence of electromagnetic field influence the arc to rapidly move over entire cathode surface arc is extremely dense, high level of ionization, clusters even macro-particles or droplets can be used in reactive mode
Introduction Tereza Schmidtova Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying
Disadvantages Introduction Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying cathode spot stays too long macro-particles or droplets are poorly adherent, distort the coatings worse case - cathode material has low melting point (Al), cathode spot can evaporate through target to baking plate or into the cooling system to prevent this the magnetic field is widely used, even for cylindrical configuration the cathode rotates some companies also use filtered arcs that use magnetic fields to separate the droplets from the coating flux Advantages - fast, highly dependable cutting tools, hard films, nanocomposites (TiN, TiAlN, CrN, ZrN, AlCrTiN, TiAlSiN) DLC; filtering of macro-particles required, high percetengae of sp 3 bonds
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying Electron beam physical vapour deposition - EB target anode is bombarded with an electron beam (charged tungsten filament under high vacuum) electron beam causes atoms from the target to transform into gaseous phase atoms precipitates into solid form on every surface high deposition rate (0.1 µm to 100 µm per minute) at relatively low substrate temperatures
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying Ion beam assisted deposition
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying Disadvantages simple geometries, coating is line-of-sight (rotation and translation of the shaft helps) non-uniform evaporation rate as a result in filament degradation in electron gun Advantages accessible low and high deposition rates, high material utilization efficiency possible structural and morphological control of films Application - hard coatings (cutting tools), electronic and optical films
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying Pulsed laser deposition - PLD high power pulsed laser beam is focused to strike the target material target material is vapourised and deposited on substrate 1965 Smith and Turner utilized ruby laser for thin film deposition reactive mode possible energy is converted to electronic excitation and then into thermal, chemical and mechanical energy resulting in evaporation, ablation, plasma formation and even exfoliation ejected species contain also clusters, molten globules,... penetration depth of laser beam 10 nm for most materials (type of material and laser wavelenght)
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying Disadvantages resputtering of deposited film decrease in deposition rate Advantages versatility (changing distances, laser wavelength,...) small target size Application - SiO 2, SiC, TiN, semiconductors, metallic systems, polymers, ferrroelectric materials,...
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying Sputter Deposition ejecting of target material towards the substrate (momentum transfer) various geometry (diode, triode, planar, asymmetrical, ion beam) reactive mode possible presence of magnetic field enhanced sputtering and can guide sputtered ion flux towards substrate - magnetron sputtering HIPIMS
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying Thermal spraying; Plasma spraying metled or heated materials is sprayed onto surface coating precursor is heated by plasma/arc or combustion flame large area, high deposition rate, thick layers (metals, alloys, ceramics, plastics, composites) history 1910s (flame spraying, wire arc spraying); plasma spraying 1970s
Vacuum Evaporation Cathodic Arc Deposition Electron beam physical vapour deposition Pulsed laser deposition Sputter deposition Spraying
Chemical vapour deposition from atmospheric pressure to ultra-high PE (MP - microwave plasma, RP - remote plasma) uses chemical reactions electroplating ion plating
Advantages Large size deposition good covering of complex surface structures Dissadvantages - high temperature (not in PE) chemical byproducts (chemical waste)
taken from [Bunshah,1994]
References R. F. Bunshah. Handbook of deposition technologies for films and coatings: Science, Technology and, 2 nd, editionnoyes Publications, 1994, ISBN 0-8155-1337-2 en.wikipedia.org www.google.com
Thank you for your attention!