[labnetwork] Piranha processing vessels

[Paolini, Steven]

Keith,
  Do NOT use PVC. If the acid doesn’t eat it, the heat generated from the exothermic reaction will. This would be quite dangerous. If you have to use glass, quartz is the best way to go. If you want to use polymer, I would highly recommend Teflon over polypropylene or polyethylene for its heat and chemical resistance, it is well worth the added cost. Keep in mind that piranha etch will reach temperatures well over 100 Deg. C. when spiked with H2O2 and increases the corrosive properties of the sulfuric. Even though a particular material might be rated to resist high temperatures, it doesn’t mean that it will resist the abuse it will get from this etch. I have cleaned up my share of piranha mishaps and the majority of them had to do with containers or drain traps in the sink that were PVC.
Steve Paolini
Equipment Dood
Harvard University Center for Nanoscale systems.

From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Keith Franklin
Sent: Thursday, April 28, 2016 1:59 PM
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] Piranha processing vessels

Good day all,

We're currently revisiting what vessels or tanks we use for processing with hot piranha.  Our most common application is for cleaning a partially filled cassette of 4" Si wafers.  We typically purchase Pyrex 6944 vessel and have our glass shop cut them down to a more reasonable height.  In our last purchase cycle, we noticed that the ID has changed ever so slightly and it's now challenging to squeeze our standard Entegris cassette into this vessel.  We're currently looking into custom machined PVC, PP,  Teflon & Quartzware, as well as off the shelf small volume tanks, etc.

I'm hoping to better understand what other similar labs are using for this application (& potentially 6" wafers as well).  Any advice or feedback would be greatly appreciated.

Kind Regards,
Keith


Keith Franklin

Operations Manager

University of Alberta - nanoFAB

W1-060 ECERF Building

9107 - 116 Street

Edmonton, Alberta

Canada T6G 2V4                     Ph: 780-492-0170
www.nanofab.ualberta.ca<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.nanofab.ualberta.ca&d=CwMFaQ&c=WO-RGvefibhHBZq3fL85hQ&r=-H4Z_jeDfTYjnKPXor15vLwzBllmg8gFrb9m_k9OGks&m=JtVsPdXo9LMAxOQ1vE5gY9YAsBgbjGiOCY3JJnEzq5I&s=aglKQTD-5hMf-grL8GLXxIExZzmT9Lhit8wcEU6r7VU&e=>
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