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CVD( Chemical Vapor Deposition)
PVD ( Physical Vapor Deposition )
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Deposition methods
PVD ( Physical Vapour Deposition Füüsikaline aurufaasist sadestamine)
CVD ( Chemical Vapour Deposition – Keemikaline aurufaasist sadestamine )
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Metalorganic CVD
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Plasma Enhanced CVD (PECVD)
PECVD
– plasma-enhanced CVD:
– glow-discharge plasmas (usually RF field: 100 kHz – 40 MHz), or MW – 2.54 GHz plazma at reduced gas pressure between 50 mtorr and 5 torr) are sustained within chambers where simultaneous 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 them by diffusing into the underlying matrix
- diamond films
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Plasma Enhanced CVD (PECVD)
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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.
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Diamond films
Polycrystalline diamond films
Nanocrystalline diamond films
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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)
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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.
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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.
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PVD – Physical Vapor Deposition
Evaporation
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.
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Electrically heated evaporation sources (Thermal evaporation)
• Pulsed laser deposition
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Electron-beam evaporation
• Molecular beam epitaxy
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Ion beam assisted evaporation
• Discharge based deposition methods (sputtering, arc evaporation )
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Termilise aurustuse põhimõtteline skeem
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Molecular beam epitaxy
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1. SPUTTERING
(katood-ioonpommitus)
Magnetron Sputtering
DC
RF
2. Cathode ARC ion
Plating
(kaarleek sadestamist)
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Katood-ioonpommitussadestus
Magnetron sputtering
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Platit π70 and π -80
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1. 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
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Vaba energia
F = U-TS
U-sisseenergia
T-temperatuur
S-entroopia
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γΔσ = ΔF
Island growth
Volmer-
Weber
Layer-by-layer
Frank-van der
Merwe
Layer-bylayer+island
Stranski-
Krastanov
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