Transcript Nano-Fab Simulator Layout

NanoFab Trainer Update
Nick Reeder, January 18, 2013
Update to Wet Etch Code
• Wet etch rates are now interpolated from
look-up tables, with rates increasing as bath
temperature increases.
– Question: I arbitrarily set each etch rate at 50C
to be double the rate at 20C. Is that a
reasonable first approximation?
Update to Dry Etch Code
• Dry etch rates are now interpolated from
look-up tables, with rates dependent on
power and pressure.
• Currently, in the lookup tables:
– Rates increase linearly with power.
– Rate-versus-pressure curves have profile
discussed at our May 17, 2012 meeting:
Rate Multiplier
2.5
2
1.5
1
0.5
0
Pressure
Update to Evaporate Code
• Deposition rates for evaporation are now
interpolated from look-up tables, with rates
dependent on voltage and current.
• Currently, the lookup tables for all
evaporable materials hold the same data
points, which are correct for Cr:
Voltage (kV)
Current (mA)
Rate (Å/sec)
6.5
36
2
7.5
30
5
7.5
40
10
Update to Sputter Code
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Deposition rates for sputtering are now interpolated
from look-up tables, with rates dependent on
pressure and power.
Currently, the lookup tables for all sputterable
materials hold the same data points, which are
correct for Al:
Pressure (mtorr)
Power(W)
Rate (Å/sec)
4
10
0.15
4
20
0.09
4
50
0.25
4
100
0.5
4
150
1.6
4
300
2.8
7
200
1.45
Menu Updates
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Added new menu options to let user view (but not
edit) spin speed curves, etch-rate lookup tables, and
deposition-rate lookup tables.
Can extend this code to let the user edit the values
too.
Other Updates
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Based on feedback from Summer Institute demo:
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Rewrote Define Mask code for smoother operation of
sliders.
Added acetone as a wet etchant.
To-Do List
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Implement look-up tables to compute deposition rates for CVD based on usersupplied pressure & temperature.
Populate evaporation and sputter look-up tables with values.
Fix expose, develop, oxidize, polish code to compute depth from user-supplied
values.
Continue writing bake code; need realistic values for S0 and .
In expose code, implement diffraction of UV in air and absorption within resist,
with dependence on solvent content from bake code.
Fix etch code so that (for photoresist) etch rates depend on solvent content from
bake code.
Fix spin-coat code so that resist does not adhere to underside of horizontal
surfaces.
Write new code for
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Lift-off
Clean
Profilometer
Write time-cost-quality code for all operations.
Write online help text.
Produce videos, photos, text for Tutorial tab.
Activity
Not started
Clean
Partial
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Spin coat
Simulation coding
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Bake
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Mask/Expose/Develop
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Evaporate
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Thermal oxidation
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CVD
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Sputter
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Wet etch
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Dry etch
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Lift off
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Polish
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Implant
Track time, cost, quality of each process
User -interface coding
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History with option to revert
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Save/open history files
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Edit colors
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User-defined materials
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Profilometer
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Producing embedded media (videos, photos, etc.)
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Testing
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Documentation
Complete
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