[labnetwork] Cleanroom gowning to handle resists and developers

[Zuzanna A. Lewicka]

Hello Mario,
At our Micro/Nanofabrication Center, we are currently re-evaluating safety protocols for TMAH-based developers, as evidence from toxicology and clinical cases shows that TMAH presents not only a corrosive hazard but also a risk of rapid systemic toxicity following skin exposure.
We are therefore assessing whether additional protection—such as enhanced splash protection and more resistant gloves—may be appropriate.
For context, these risks have been recognized in industry, including IBM toxicology work that led to stronger safety controls:
https://sesha.org/wp-content/uploads/2019/12/dizio_proceedings_2011.pdf
https://www.youtube.com/watch?v=uBjvRbGnMpM
Best regards,
Zuzanna Lewicka
Associate Director, Micro/Nanofabrication Center, Princeton Materials Institute
________________________________
From: labnetwork <labnetwork-bounces at mtl.mit.edu> on behalf of Jing Guo <jg78 at rice.edu>
Sent: Tuesday, April 21, 2026 2:51 PM
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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