Cambridge ALD: Difference between revisions

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== Standard operating procedure ==
== Standard Operating Procedure ==
* Log your process in the Excel notebook.
===ALD1===
* Check the nitrogen bottle:
<div style="background-color: #c0c0c0; border: 1px solid #00000; padding: 10px; border-radius: 5px;">
** Verify that the main valve on top of the bottle is open.
====Loading====
*: ''The N2 flow in idle state is '''5 sccm'''.''
# Log your process in the Excel notebook.
** Verify that the main bottle pressure is at least 5 bar.
# Check the nitrogen bottle: ''If line pressure is ~0bar, contact the cleanroom staff.''
** The line pressure should be  >1 bar (ALD1) 1-2 bar (ALD2).
# Make sure the valves of '''all''' precursors inside the ALD tool are closed.
*: ''If line pressure is outside the range, please report it to the cleanroom staff.''
# Run recipe '''chamber prep''' to pump out any residual gas in the gas lines.
* Make sure the valves of '''all''' precursors inside the ALD machine are closed.
# Press the round '''VENT''' button.
* Run recipe ''Default_cleaning'' to pump out any residual gas in the gas lines.
# Open the metal lid.
* Press the '''VENT''' or '''VENT REACTOR''' button.
# Put your sample inside, roughly in the center, away from the gas inlet and outlet.
* Open the metal lid.
#: Check whether the rubber O-ring is properly seated.
* Put your sample inside, roughly in the center, away from the gas inlet and outlet.
# Close the metal lid. Check that the lid is aligned to sit directly on top of the reactor chamber.
*: Check whether the rubber O-ring is properly seated.
# Press the round '''PUMP''' button.
* Close the metal lid. Check that the lid is aligned to sit directly on top of the reactor chamber.
# Place the metal cage on top of the tool.
* Press the '''PUMP''' or '''PUMP REACTOR''' button.
# Open relevant precursor valves.
*: Pressure with flow set to 0: ~5e-2 Torr or lower.
# Run your recipe.
* Place the metal cage on top of the tool.
====Unloading====
* Open relevant precursor valves.
# Close precursor valves.
* Run your recipe.
# Press the round '''VENT''' button.
<blockquote style="background-color: #F0F0F0; border: dashed thin grey;">
# Place the metal cage on the side of the tool.
* Pressure with 20 sccm N<sub>2</sub> flow present: low e-1 Torr.
# Take out your sample. Check the rubber o-ring.
* ALD1 pulse lengths: H<sub>2</sub>O ~0.5 s, HfOx TDMAH 0.2 s, AlOx TMA 0.02 s.
# Press the round '''PUMP''' button.
* ALD2 pulse lengths: H<sub>2</sub>O ~0.02 s, HfOx TDMAH 0.2-0.5 s.
# Run recipe '''chamber_finalise'''.
</blockquote>
# Leave the system in the appropriate state.
* Close precursor valves.
</div>
* Press the big round '''VENT''' or '''VENT REACTOR''' button.
* Place the metal cage on the side of the tool.
* Take out your sample. Check the rubber o-ring.
* Press the big round '''PUMP''' or '''PUMP REACTOR''' button.
* Run recipe ''Default_heater_set''.
* Verify that the flow is set at 5 sccm.


== Witness samples ==
== Witness samples ==

Revision as of 08:58, 15 June 2026

Cambridge ALD
Picture of Cambridge ALD text
Essentials
Full nameSavannah S100 (gen. 1)
ManufacturerCambridge NanoTech (Veeco)
DescriptionAtomic layer deposition system
LocationCleanroom 1 (03.2.209A)
Cleanroom 2 (03.2.203B)
Responsibility
PrimaryHarry
SecondaryMartin

Page last updated: 11 Nov 2025 Two nearly identical Savannah S100-like systems are used for atomic layer deposition of aluminum, hafnium, titanium, zirconium, and oxide.

Other material deposition alternatives at the NBI cleanroom:


Growth per cycle (GPC) monitoring

  • ALD1 HfOx
    ALD1 HfOx
  • ALD1 AlOx
    ALD1 AlOx
  • ALD2 HfOx
    ALD2 HfOx

Available processes

Deposited material Precursor ALD1 ALD2 Ref.
Hafnium oxide (HfOx, HfO2)
TDMAH
tetrakis(dimethylamino)hafnium
[(CH3)2N]4Hf
Yes Yes [1]
Aluminum oxide (AlOx, Al2O3)
TMA
trimethylaluminum
(CH3)3Al
Yes Yes [2]
Titanium oxide (TiOx, TiO2)
TTIP
Titanium(IV) isopropoxide
Ti[OCH(CH3)2]4
 Yes No [3]
Zirconium oxide (ZrOx, ZrO2)
TDMAZ
Tetrakis(dimethylamido)zirconium(IV)
[(CH3)2N]4Zr
 No Yes [4]

Videos on operating the tools

Video on how to operate ALD 1:

Video on how to operate ALD 2:


Standard Operating Procedure

ALD1

Loading

  1. Log your process in the Excel notebook.
  2. Check the nitrogen bottle: If line pressure is ~0bar, contact the cleanroom staff.
  3. Make sure the valves of all precursors inside the ALD tool are closed.
  4. Run recipe chamber prep to pump out any residual gas in the gas lines.
  5. Press the round VENT button.
  6. Open the metal lid.
  7. Put your sample inside, roughly in the center, away from the gas inlet and outlet.
    Check whether the rubber O-ring is properly seated.
  8. Close the metal lid. Check that the lid is aligned to sit directly on top of the reactor chamber.
  9. Press the round PUMP button.
  10. Place the metal cage on top of the tool.
  11. Open relevant precursor valves.
  12. Run your recipe.

Unloading

  1. Close precursor valves.
  2. Press the round VENT button.
  3. Place the metal cage on the side of the tool.
  4. Take out your sample. Check the rubber o-ring.
  5. Press the round PUMP button.
  6. Run recipe chamber_finalise.
  7. Leave the system in the appropriate state.

Witness samples

In CR1 and CR2, you can find various witness samples depending on the properties that you would like to explore:

  • Only thickness: Si (001) 1 inch wafers
  • Thickness and breakdown voltage: Si (001) 15x15 mm2 back-side Au plated

It is recommended to ash the witness chips for 2 mins before loading them in the ALD tool.

File logs

  • Recipe file location
    ALD1: C:\Savannah\Users\Standard\
    ALD2: C:\Cambridge Nanotech\Recipes\
  • Log file location
    ALD1: C:\ALD data. Includes pressure data, screenshot at termination.
    ALD2: C:\Cambridge Nanotech\Log\. Includes pressure and heater temperature data, screenshot at termination, software event logs.

Troubleshooting

Pressure reading obviously wrong (above 1e3 Torr or below 1e-4 Torr)
Pressure gauge failure. Unplug the network cable from the small square pressure gauge beneath the chamber and plug it back in. The pressure reading should return to expected values.
No peak visible during precursor pulse
  • Precursor valves closed. Make sure the relevant precursor valves are open. Consult the labels on the inside of the door.
  • Pulse time too short. Select the lowest plotting interval and check whether you can spot a small peak when the automatic valve opens. Increase pulse time as needed.
Cannot open lid upon venting
  • Chamber pressure still below atmosphere. Confirm pressure reading in software. If pressure is below 5e2 Torr, check whether the nitrogen bottle valve is open.
  • Rubber O-ring can get stuck to the lid. Gently but firmly lift the lid. Reseat the O-ring if needed.
What is the best plot time to graph the process pressure?
It is recommended to plot only several pulses, for example 30 seconds or 1 minute total plot time. Setting this value to 1 hour during a run can reduce delay precision, because with a 1 hour plot time many data points need to be refreshed, which consumes a lot of processing resources. It is possible to set the plot time to 1 hour to get an overview of pulse heights, but plot times > 5 minutes are not recommended during a run. [1]
What are the recommended heater temperatures?
These are the recommended temperatures from the manual:
  • Heaters for the trap (#6):150°C
  • Stop valve (#7): 150°C
  • ALD valve oven (#10): 150°C
  • Precursor Manifold: 150°C
  • Reactor heaters (#8 and #9): 100-200°C
    • ALD1 (#8 and #9): 110°C

Remote access

  • TeamViewer: ALD1, ALD2
  • LogMeIn: ALD1 (CR1), ALD2 (CR2)


References

  1. ↑ Savannah Maintenance Manual
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