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Deposition (PVD and CVD). Plan of presentation. Deposition methods CVD( Chemical Vapor Deposition) PVD ( Physical Vapor Deposition ) Principles, processes on the surface . Deposition methods classification 2. Deposition methods
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Plan of presentation • Deposition methods CVD(Chemical Vapor Deposition) PVD ( Physical Vapor Deposition ) • Principles, processes on the surface
Deposition methods classification2 Deposition methods PVD ( Physical Vapour Deposition - Füüsikalineaurufaasistsadestamine) CVD ( Chemical Vapour Deposition – Keemikaline aurufaasist sadestamine )
Plasma Enhanced CVD (PECVD) PECVD – plasma-enhanced CVD: – glow-discharge plasmas (usually RF field: 100 kHz – 40 MHz), or MW – 2.54 GHzplazma at reduced gaspressure between 50 mtorr and 5 torr) are sustained within chambers wheresimultaneous vapor-phase chemical reactions and film depositions occur – plasma activation of reactions (average electron energies range from 1 to 10 eV) ! chemical reactions occur at much lower temperatures than in thermal CVD Main applications of PECVD: - microelectronics (DRAM cells) - plasma modification of metal surfaces (nitriding, carburizing): the atoms of nitrogen and carbon that deposit on metal surfaces modify thembydiffusing into the underlying matrix - diamondfilms
PECVD (MW) Plasma Enhanced CVD Microwave plasma chemical vapor deposition system for high quality poly-, mono- and nanocrystalline diamond films. MW frequency – 2.54 GHz.
Diamond films Polycrystalline diamond films Nanocrystalline diamond films
Application of diamond films • - Semiconductor Devices, RF MEMS, • Creation of novel surface materials, i.e. • super‐hydrophobic surfaces, • super‐hydrophilic surfaces (biocompatible surfaces) • Fabrication of 3‐D diamond probes and structures • for field emission • High selectivity and high voltage range electrochemical • sensors and electrodes • Defects in diamond (famous NV centers) for single photon sources, • quantum computers (qubit), quantum cryptography,… • - Sensors (quantum sensing in biology and medicine) • Tribology • Current research projects in our Department include: • Growth of the diamond tips for Atomic Force Microscopy • Investigation of the diamond films growth (fractal approach) • Investigation of tribological properties of the diamond films (nanowaves on the wear scars) • …………………….
Announce Diamond films prepared by Chemical Vapor Deposition Dr. V. Ralchenko , Natural Sciences Center of Prokhorov General Physics Insitute RAS, Diamond Materials Laboratory, Moscow, Russia Lecture agenda: • 1. Chemical Vapor Deposition (CVD) of diamond films: Principles and methods • 2. Growth processes for nano/micro/mono-crystalline films in microwave plasma • 3. The properties of diamond films • 4. Diamond films processing • 5. Applications of diamond films Lecture venue - Tallinn University of Technology, Department of Materials Engineering Lecture will be held on 20 November 2013.
Atomic Layer deposition (CVD like) Atomic scale deposition. ALD is similar in chemistry to CVD, except that the ALD reaction breaks the CVD reaction into two half- reactions, keeping the precursor materials separate during the reaction.
PVD – Physical Vapor DepositionEvaporation Evaporation: controllably transfer atoms from a heated source to a substrate located a distance away, where film formation and growth proceed atomistically. Thermal energy is imparted to atoms in a liquid or solid source such that their temperature is raised to the point where they either efficiently evaporate or sublime. • Electrically heated evaporation sources (Thermal evaporation) • Pulsed laser deposition • Electron-beam evaporation • Molecular beam epitaxy • Ion beam assisted evaporation • Discharge based deposition methods (sputtering, arc evaporation )
Thermal evaporation (PVD) Termilise aurustuse põhimõtteline skeem
Discharge based deposition methods5 • SPUTTERING • (katood-ioonpommitus) • MagnetronSputtering • DC • RF • 2. Cathode ARC ion • Plating • (kaarleek sadestamist)
Sputtering(DC and RF)7 Katood-ioonpommitussadestus Magnetron sputtering
What you need to remember Difference between PVD and CVD. - PVD – evaporation or collision impact of the solid target - CVD – chemical processes in gaseous phase and the surface 2. The versatility of deposition methods is due to particular purposes including quality of the films (coating), size of sample, deposition price, …… 3. The quality of the film is a leading factor in the development of new deposition methods. Nowadays, those are: a. Layer by layer deposition :examples – MBE (PVD), ALD (CVD) b. PECVD
Mechanism of Growth10 Vaba energia F = U-TS U-sisseenergia T-temperatuur S-entroopia γΔσ = ΔF Layer-by-layer Frank-van der Merwe Layer-by-layer+island Stranski-Krastanov Island growth Volmer- Weber