[labnetwork] Oxidation Furnaces Time/Temperature

[Vito Logiudice]

Dear Kamal,

I would stay away from oxidation times that are too short. Five minutes seems extremely short to me; I would probably keep it to a minimum of 15-20 minutes, if not more.

You might be able to improve repeatability in the achievement of “minimum thickness” oxides by diluting your O2 with UHP N2. For instance, you can try flowing a ratio of 1:1 O2 to N2 during the oxidation step and seeing how that compares with the oxide thickness achieved with 100% O2. You can then try other ratios depending on the results achieved. For each given condition, I would run at least 2-3 test runs to confirm stability/repeatability at that specific condition before experimenting with another condition (remember to only change one furnace variable at a time for each test run). Good luck.

Best regards,
Vito
--
Vito Logiudice  P.Eng.
Director of Operations, Quantum NanoFab
University of Waterloo
Lazaridis QNC 1207
200 University Avenue West
Waterloo, ON           Canada N2L 3G1
Tel.: (519) 888-4567  ext. 38703
Email: vito.logiudice at uwaterloo.ca<mailto:vito.logiudice at uwaterloo.ca>
Website: https://fab.qnc.uwaterloo.ca


From: Kamal Yadav <kamal.yadav at gmail.com<mailto:kamal.yadav at gmail.com>>
Date: Saturday, July 4, 2015 at 4:46 AM
To: "labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>" <labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>>
Subject: [labnetwork] Oxidation Furnaces Time/Temperature

Dear All,

We have furnaces [Atmospheric pressure and LPCVD] from Ultech Inc., Korea.

We have 4" size substrate size quartz tubes furnaces. After temperature ramp up to desired temperature, oxygen flow starts and we have done upto a minimum time of 5 min, after which oxygen flow stops and nitrogen flows for sometime and furnace gets cooled down to 400/500 before we unload.

We believe there must be some minimum time the oxygen should be flown to achieve reliable and repeatable oxide thickness as it will take some time for oxygen to stabilize in the furnace.

As thin oxides are required, we are also considering changing the temperature to 750 Deg C, to achieve minimum thickness. Both temperature and time could be optimized in order to achieve minimum thickness.

Which, Temperature or time or both, is best to change and how far one can go, is my question to achieve minimum thickness.

Thanks a lot!

--
Thanks,
Kamal Yadav
Sr. Process Technologist
Electrical Engineering
IIT Bombay
Mobile: 7506144798
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