[labnetwork] Oxford Wafer Jam/Break

[Paolini, Steven]

Long,
  I misinterpreted your message yesterday. It would be wise to take Justin's advice, he is the top dog when it comes to Oxford equipment.
Steve

Steve Paolini
Principal Equipment Engineer
Harvard University Center for Nanoscale Systems
11 Oxford St.
Cambridge, MA 02138
617- 496- 9816
spaolini at cns.fas.harvard.edu
www.cns.fas.harvard.edu

From: labnetwork <labnetwork-bounces at mtl.mit.edu> On Behalf Of Moreau, Justin
Sent: Wednesday, June 22, 2022 7:59 AM
To: Chang, Long <lvchang at Central.UH.EDU>; labnetwork at mtl.mit.edu
Subject: Re: [labnetwork] Oxford Wafer Jam/Break

Hi Long

By jamming does the handler just stall?
I don't think adding more time or removing PR from your wafer edge will help.
I suspect one of the handling sensors isn't made, you have a mechanical bind (ff feedthrough, gearbox, linear bearing) or you have a failing drive transistor.

Looking at your image- Slit valve is open, clamp is up, lift is up, arm is extended

Is your "arm out"sensor made? If no you should adjust the arm out sensor.

If the arm out sensor is made. Check for a mechanical bind-  Remove the mounting plate that holds the motor and gearbox assy. You can then try and rotate the ferrofluid feedthrough shaft by hand.
If you can rotate, you don't have a bind.

This looks like a Blue PLC control system so it would likely be the Q4 transistor on the LL control card that's the problem. Its mounted just below the LL chamber. It can overheat and intermittently work. Q4 controls the drive back into the LL.
It will also discolor so it should be easy to spot. You can replace it with a ZTX450 NPN.



Hope this helps








[University of Massachusetts Lowell]
Justin Moreau
Sr. Lab Manager, Nanofabrication Core
CORE RESEARCH FACILITIES
ETIC
E: Justin_Moreau at uml.edu<mailto:Justin_Moreau at uml.edu>
T: 978-934-3615


From: labnetwork <labnetwork-bounces at mtl.mit.edu<mailto:labnetwork-bounces at mtl.mit.edu>> On Behalf Of Chang, Long
Sent: Tuesday, June 21, 2022 2:51 PM
To: labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>
Subject: [labnetwork] Oxford Wafer Jam/Break

This e-mail originated from outside the UMass Lowell network.
________________________________
Hi Guys,

After etching through 380um of Silicon, the loading arm would get jammed during unloading, see photo. The problem was fixed by adding a 15min step to do nothing step to allow the clamp to cool down before unloading. Now the problem is back and the plan is to increase the cool down time until it stops jamming. Is there a better way to avoid this problem? Should the PR on the wafer edge be removed?

Thanks,
Long
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