5
Introduction
Why MOCVD ?
❖ Very high quality of grown layers (high growth rate and doping uniformity/reproducibility)
❖ High throughput and no ultra high vacuum needed (-compared to MBE) (Economically advantageous, high system up-time)
❖ Highest flexibility (Different materials can be grown in the same system)
❖ Growth of sharp interfaces possible very suitable for heterostructures, (e.g., multi quantum wells (MQW))
Some of the sources like AsH3 are very toxic.
4
Introduction
Some about the name of MOCVD
In the reference, MOCVD also have some other names. Different people prefer different name. All the names refer to the same growth method.
3
Introduction
Compare of epitaxial methods
Growth method
LPE (Liquid phase epitaxy)
VPE (Vapor phase epitaxy MBE (Molecular Beam Epitaxy) MOCVD (Metal-Organic Chemical Vapor Deposition)
Reactor-1
11
The MOCVD technique and growth system
Reactor-2
12
The MOCVD technique and growth system
15 -52.5 -15.8 -82.5
88 -32 -28 175
Log[p(torr)]=B-A/T
7
Metalorganic compounds
MO compounds supply system
8
The MOCVD technique and growth system
Components of a MOCVD System
No Al contained compound, thick layer
1958 Deposit epilayer at 1967 ultrahigh vacuum
Hard to grow materials with high vapor pressure
1968 Use metalorganic compounds as the sources
Physics Department, Nanjing University
2-Dec-10
2
Outline
1. Introduction 2. Metalorganic compounds 3. The MOCVD technique and growth system 4. Epitaxial growth basic 5. Example: MOCVD growth of GaN 6. Materials Characterizations
gas handling system
reactor with heated susceptor
control unit
vacuum system
scrubbing system
9
The MOCVD technique and growth system
10
The MOCVD technique and growth system
The AIX 2800G4 HT in the 42x2 inch configuration
1
MOCVD technology and epitaxial growth
Chen Peng
Institute of Optoelectronics，Nanjing University & Yangzhou
P at 298 K (torr) 14.2 0.041 238 4.79 1.75 0.31 8.53 0.05 NhomakorabeaA
2780 3625 1825 2530 2830 2815 2190 3556
B
10.48 10.78 8.50 9.19 9.74 8.94 8.28 10.56
Melt point (oC)
6
Metalorganic compounds
MO compounds
Compound
(Al(CH3)3)2 Al(C2H5)3 Ga(CH3)3 Ga(C2H5)3 In(CH3)3 In(C2H5)3 Zn(C2H5)2 Mg(C5H5)2
TMAl TEAl TMGa TEGa TMIn TEIn DEZn Cp2Mg
time features
limit
1963 1958
Growth form supersaturated solution onto substrate
Use metal halide as transport agents to grow
Limited substrate areas and poor control over the growth of very thin layers
• MOCVD • OMCVD • MOVPE • OMVPE
(Metalorganic chemical vapor deposition) (Organometallic CVD) (MO vapor phase epitaxy)
• AP-MOCVD (Atmosphere MOCVD) • LP-MOCVD (Low pressure MOCVD)