[labnetwork] Cleanroom gowning to handle resists and developers

[Jeff Salzmann]

Mario,

Jing brings up a good point. I do not permit 25% TMAH in my facility; while it is indeed a strong base, it is also a contact poison (and so are 2.5% developers).

Note that this is not something that shows in the SDS for some developers.

I require users to wear chemical gloves/apron/shield and safety glasses during manual development. The attached paper should provide some insight.

Regards,
Jeff



Jeff Salzmann
Research Assistant Professor of Electrical Engineering
Cleanroom Manager, Shared Instrumentation Laboratories
School of Engineering and Applied Sciences
University at Buffalo, 114A Davis Hall
105 White Road
Buffalo, NY 14260-2500
Tel: 716.645.2584

From: labnetwork <labnetwork-bounces at mtl.mit.edu> on behalf of Jing Guo <jg78 at rice.edu>
Date: Tuesday, April 21, 2026 at 19:47
To: Beaudoin, Mario <beaudoin at physics.ubc.ca>
Cc: labnetwork at mtl.mit.edu <labnetwork at mtl.mit.edu>
Subject: Re: [labnetwork] Cleanroom gowning to handle resists and developers

Hi Mario,

For most photolithography spin-coating and development processes, we don’t request extra PPE. Generally users are wearing cleanroom coveralls, nitrile gloves and safety goggles. Most positive MIF developers are TMAH (2.1~2.3% weight concentration) solutions.

But we will always bring up the high concentration TMAH, 25% TMAH (Aqueous solution) to attention. Some users use 25% TMAH as a HSQ ebeam resist developer. 25% TMAH is a strong base which could cause severe caustic burns. Users must wear a secondary PPE to use 25% TMAH including Tychem 4000 Apron, double/triple long sleeve nitrile gloves (disposable) , safety goggles plus face shield and silver shield chemical resistant boot covers. Photolitho users should never touch TMAH 25% bottles even they are also stored in the general base cabinets.

We set up secondary PPE stations beside our benches. HF bench has its own. Users can always protect themselves when necessary.



Best,

Jing
---------------------------------------
Jing Guo Ph.D.
Cleanroom Manager/Research Scientist
SEA Cleanroom (SST 017)
Rice University
Houston, TX
jeanne.guo at rice.edu
713-348-8227

On Apr 20, 2026, at 5:37 PM, Beaudoin, Mario <beaudoin at physics.ubc.ca> wrote:


Dear Network,

In our cleanrooms, we handle photoresists and developers with common cleanroom apparel (coveralls, hoods, nitrile gloves and eye protection).  Do any of you require extra special aprons, full visors and 4H gloves?  I've worked in many cleanrooms and never encountered such requirements.

Mario

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<Mario Beaudoin SBQMI sig 3.jpg>
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