CHEMICAL VAPOR DEPOSITION (CVD) A process of formation of a non-volatile solid film on a substrate from the reaction of vapor phase chemical reactants containing the right proportion of constituents. ELEMETRY STEPS IN CVD : Introduction of reactive species into a reactor Diffusion and Adsorption of the reactants onto the surface Reaction at the surface to form the solid Desorption of by products from the surface Diffusion of by products and un-reacted reactants away from the surface and transport of by products out of the reactor
Deposition rate is determined by rate limiting step Effluents out of the reactor Effluents out of the reactor Substrate ZnS (s) + H2 (g), H Zn Adsorption & reaction H2S Ar Zn fu f i D Diffusion of by-products Zn Ar e h t of n sio ts n a ct a e r H2 S H2 S fu f i D Ar Zn + Ar ts n a act H y-products Diffusion of b H H2S (g) + Zn (g) re e Ar th of n sio H2 S Ar H2 S H2S Ar Ar Zn H2S + Ar Reactive species into a reactor
CONTROL OF ELEMENTARY STEPS Chemical Reactions Reactor Type and Geometry Process parameters (Temperature, Pressure, Flow rate and time) Transport phenomena (Mass and Heat) Kinetics and Thermodynamics Hence, CVD technique combines several scientific and engineering disciplines
CVD Reactor Types CVD Type Advantageous Disadvantages APCVD 100 mbar -1000 mbar Simple, Fast, Low temperature Contamination Non uniformity LPCVD 1 mbar 30 mbar Purity, Uniformity Slower, Vacuum, High Temperature PECVD 1 mbar 10 mbar 100kHz to 2.45 GHz Fast, Low temp. Contamination Cost Laser Induced CVD Metal-organic CVD Plasma Assisted CVD High Density CVD L-CVD MOCVD PACVD HDCVD Vapor Phase Epitaxy Atomic Layer Deposition VPE ALCVDD Cold wall CVD : Only substrate heating by Inductive heating( RF, eddy), Optical heating (lamp), Resistive heating ( suceptor) Adv/Disadv. No deposition in chamber walls but temp. monitoring and uniformity are issues. Hot Wall CVD : Heat entire system and generally used.
TYPICAL CVD REACTIONS Example : CH4 + TiCl4 TIC + 4HCl BCl3 + NH3 BN + 3HCl SIH4 + NH3 Si3N4 +H2 CH3Cl3Si +H2 SiC + 3HCl Mastering the process chemical reaction by the mastering the technology
MPA Industrie expertizes : Design and construction of customized turn key CVD reactors. Chemical and physical engineering of reactor Special gas handling ( toxic, corosive, explosible) Liquid source handling (storage and dosing) specialist Solid source development : high temperature chlorination of metal Vacuum technic and effluent trapping Process control
SPECIAL GAS AND LIQUID SOURCE HANDLING
Reactor design whatever the size Temperature up to 2200 C RF, DC, MW plasmas
Vacuum techniques applied to CVD processes Dry and wet scrubbing stations
PROCESS CONTROL
FULL OFFER Hazardous analysis Chemical field knowledge Nuclear field knowledge CVD consultancy CAD departement
LARGE FIELD OF ACTION FROM LABORATORY SCALE TO INDUSTRIAL SCALE
Process mastering: Thermodynamic Reactor geometry Caracterization ( X, MEB,Transmission IF
Example: metallurgy Coated Hard metal for machining Coated steel for steel forming Target is hardness, low friction coefficient, thermal resistance Materials: TiC/TiCN/TIN/Al203
Example: Flat glasses Infra red filter self cleaning layer- TC0 Example : Bio material Low friction coefficient combined with body compatibilty Example : Nuclear Neutron caption, fission element trapping Example : Space Space mirror, heat shield
Example: Aircraft, launcher C/C for brake pad, random, C/SiC composite Example : Infra red vision ZnS dome for laser guiding Other examples : Solar cell, nano materials
MPA Indutrie force According to a large expérience and technology mastering, the compagny is able to respond to any customer requirements. MPA Industrie strategy is : To develop partnership with end users
And to become a major actor in the CVD technologies to develop special collaboration with abroad countries (EEC, India, China, USA, Brazil).
RELEVANT REFERENCES
ORGANIZATION
Sylvain Bentivegna, CEO, managing director. Master s degree in physical engineering from ENSEA (French national graduate school in electronic engineering). Euring tittle. He set up the compagny in 1992 Plasma and thermical expertize Contribute to reactor design for process development for a wide range of materials and applications PACVD CVD - CVI consultancy EEC expert
ZA Est du Puits de la chaux BP 18 France 42650 Saint Jean Bonnefonds Contact@mpa.fr