[labnetwork] Cleanroom humidity

[Nicholas Menounos]

Hi Alex,

During my consultant days, industrial standard was strict 46-48F dewpoint control. But academic fabs typically have a broader range based on research and/or willingness to "suffer" through periods of deviation.

MIT conducted a benchmarking study of existing fabs in 2017, which produced the chart below. I have anonymized the data for clarity: university fabs are represented above the line, while LBNL is positioned below it. Notably, only one facility operated with a very wide dewpoint band, largely due to its ideal ambient environmental conditions.

[cid:image001.png at 01DC7002.FACB1150]

MIT.nano runs at 44F dew point (+/- 2F - Large fluctuations are from air handler maintenance). Maintaining this in New England (cold/dry + humid/hot) is not inexpensive or easy.

[cid:image002.png at 01DC7004.28331A10]


Nick Menounos, PE
MIT.nano - Associate Director of Infrastructure
Cell: (508) 932-0938<tel:+15089320938>

From: labnetwork <labnetwork-bounces at mtl.mit.edu> On Behalf Of Garry J. Bordonaro
Sent: Wednesday, December 17, 2025 5:18 PM
To: 'Alex Dixon' <agdixon at mines.edu>; 'Lab Network' <labnetwork at mtl.mit.edu>
Subject: Re: [labnetwork] Cleanroom humidity

Alex,

In our building we maintain 21C ( I believe) and 42% RH.  Temp is +/-1C, RH +/-2%.  Different processes are affected in different ways by these, so control is the only way to ensure consistent results.  For example, photolith is very sensitive to RH, wet chemistry to temp.

We also move ~60000 cfm through the HEPAs.


Regards,
Garry J. Bordonaro
Microlithographic Engineer
Cornell NanoScale Facility
250 Duffield Hall
343 Campus Road
Ithaca NY 14853-2700
(607) 254-4936
bordonaro at cnf.cornell.edu<mailto:bordonaro at cnf.cornell.edu>
http://www.cnf.cornell.edu/

Please acknowledge CNF in your publications:
"This work was performed in part at the Cornell NanoScale Science & Technology Facility (CNF), a member of the National Nanotechnology Coordinated Infrastructure (NNCI), which is supported by the National Science Foundation (Grant NNCI-2025233)."




From: labnetwork <labnetwork-bounces at mtl.mit.edu<mailto:labnetwork-bounces at mtl.mit.edu>> On Behalf Of Alex Dixon
Sent: Wednesday, December 17, 2025 12:12 PM
To: Lab Network <labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>>
Subject: [labnetwork] Cleanroom humidity

For those of you with climate controls in your cleanrooms, what relative humidity do your keep your cleanroom at, and how tightly do you control the fluccuations?  How significant an effect have you seen on device performance?

Our campus facilities is doing a climate control audit and asking any lab with special requirements to justify them. Any info you could share would be appreceated.

Thanks!
-Alex

__________________________________________________________


Alex Dixon, Ph.D. (He/Him)
Lab Manager
Nanofabrication and Thin Film Deposition
Shared Instrument Facility
Colorado School of Mines

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