[labnetwork] Argon in a BCl3 cylinder

[Aebersold,Julia W.]

Hi Sean.  I'm not sure if what I have to offer can help, but our cylinder is 100% BCL3 with no mixed argon.  We also have heat tape on all the gas delivery lines for it loves to condense at ambient temps.  We have noticed that during an oxygen plasma clean in the processing chamber using BCl3 that if the color is not a nice blue then we still have BCl3 trapped in the primary delivery gas line to the chamber.  If argon was injected into the cylinder then I would replace it for the concentration may be enough throw off the actual flow rate form your MFC.


Another tid bit is that we discovered after processing with BCl3 the photoresist chemistry changes and hardens and is extremely difficult to remove.  We are testing with Dyanstrip to see if that will remove the resist.


Cheers!


Julia Aebersold, Ph.D.

MNTC Cleanroom Manager

University of Louisville

2210 South Brook Street

Shumaker Research Building, Room 233

Louisville, KY  40292

(502) 852-1572

http://louisville.edu/micronano/<http://louisville.edu/micronano>


________________________________
From: labnetwork-bounces at mtl.mit.edu <labnetwork-bounces at mtl.mit.edu> on behalf of Rinehart, Sean <sean.rinehart at yale.edu>
Sent: Wednesday, June 19, 2019 1:15:26 PM
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] Argon in a BCl3 cylinder


Hello all,



Recently our facility’s BCl3 cylinder had been charged with argon, increasing the delivery pressure to 25 psi. The cause has been corrected, but now I’m evaluating whether or not the cylinder needs to be replaced, and would appreciate some advice.



Since the root issue was fixed, the pressure has slowly dropped from 25 psi to 15 psi with use. Based on this, it seems like with more use the argon should completely deplete from the cylinder, but maybe someone can tell me if that’s actually true, and if there’s a way to evaluate gas concentrations. Additionally, the plasma glow is whitish instead of pink, so there’s definitely BCl3 content in the delivered gas.



Thank you,



Sean Rinehart

Assistant Director, Cleanroom Operations

Yale University

203 432 4303


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