4. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | Nov-15
Import Geometry
Save the file: File->Save As… -> PlasmaReactor.cst
Then, import the file ‘Reactor.sat’ via File->Import->SAT:
Note: You may also just drag
and drop the SAT file into the
modeler window!
5. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | Nov-15
Imported Reactor
Shift-C
to activate
cutting plane
Design based on reactor designed at LIMHP:
[1] F Silva et al., MW engineering of plasma-assisted CVD reactors for diamond deposition,
J. Phys. Condens. Matter 21 (2009) 364202 and references therein
6. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | Nov-15
Imported CAD files are generally not parameterized. However,
CST allows to add parametric information after the import with
relatively little effort.
As an example, we will parameterize the z position of the chuck
Delete ‘components1->ChuckPipe’
Select ‘components1->Chuck’
and move it in z direction using
the ‘Transform’ option and
a parameter ‘ChuckZShift’
Parameterize the Import I
7. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | Nov-15
Place the WCS origin on top of the chuck:
Then store the WCS (‘WCS->Store
Current WCS’) under the name
‘ChuckCenter’. The stored WCS will
be used again during the postprocessing.
Parameterize the Import II
8. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | Nov-15
Select the bottom face of the chuck
and a point at the bottom of the
reactor.
Click on ‘Extrude’ to create a cylinder
from the bottom of the chuck down to
the bottom of the reactor, as defined
by the picks.
Parameterize the Import III
9. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | Nov-15
Parameterize the Import IV
Scale the extruded object by 3/5 in u and v direction to recreate the
original radius:
10. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | Nov-15
Materials I
Material names were imported, but their properties were not. Right-Click
on ‘Materials’ and select ‘Update All Properties from Material Library’ to
update all materials except ‘H-Plasma’:
You will use a macro to update the
properties of ‘H-Plasma’, so close
the dialog box with “No”.
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Set the name to ‘H-Plasma’, change the
pressure to 50 mbar, temperature to 3500
K, and the degree of ionization to 1e-6.
Then, press ‘Calculate’ (1)
This will update the numbers in the
density section. Next, press ‘Display
Only’ (2) to verify the calculated plasma
parameters:
Finally, press ‘Create’ (3) to generate the
material.
Materials II
Macros->Materials->Create Drude Material for Plasma Applications:
(1)
(2) (3)
12. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | Nov-15
Materials III
1000
1
The macro generates a regular Drude material,
equivalent to a plasma with a fixed plasma
frequency.
To activate the field dependency (nonlinear Drude
model), change the numbers for ‘Field breakdown’
and ‘Plasma maintain frequency’ as shown.
For more details about the field-dependent model:
[2] M. Funer et al., Numerical simulations of microwave plasma
reactors for diamond CVD, Surface and Coatings Technology 74 75
(1995) 221-226
[3] M. Funer et al., Simulation and development of optimized
microwave plasma reactors for diamond deposition, Surface and
Coatings Technology 116–119 (1999) 853–862
13. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | Nov-15
Plasma Material Curves
After setting the frequency
range from 2 to 3 GHz, check
the plasma material curves
under ‘1D Results’ in the
navigation tree.
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Excitation Signal Setup
Right-click on ‘Excitation
Signals’ and select ‘New
Excitation Signal’
You may also use parameters here!
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Boundary Conditions and Symmetries
Note: The material colors for ‘Steel’
and ‘H-Plasma’ were changed here
from their defaults. Feel free to adjust
them in your model to your liking.
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Port Setup
Select the top face
of the coax part to
create a waveguide
port.
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E-Field Monitor
A transient field monitor
is recommended here,
since a non-Gaussian
excitation signal is used.
Optional: Set the start
time to ‘2’ to start
recording when the
excitation signal has
reached its maximum.
A step width of ‘0.04’
represents approximately
10 samples per period.
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Solver Setup
(1)
(2)
(3)
Before starting the
solver (3), make sure to
open ‘Excitation List’
(1) and ‘Specials’ (2).
The Transient solver is
needed to capture the
nonlinear behavior of
the material.
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Excitation List
Set PowRMS=4000 and make
sure that ‘2.45GHz_Sine’ is
selected as excitation signal.
You will have to adjust the
label manually:
When finished with ‘Excitation List’ open the ‘Specials’.
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Solver Specials
When finished ‘Specials’, start the Transient solver.
Deactivate for S-Parameter
calculations of non-linear model
Activate the plasma monitor here.
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Results: Time Signals
Port input (red) and output (blue) signals under ‘1D Results->Port Signals’:
Equilibrium reached after about 9 ns
(Important for S-Parameter calculations)
