[labnetwork] Photoresist and Ebeam Resist In Same Spinner?

[Owain Clark]

We find that LOR10 is the worst culprit for clogging and will precipitate with acetone. DMSO cleans it well, but then your users ideally need barrier glove PPE to prevent anything dissolved in it crossing their skin barrier. I don't see normal nitrile cleanroom gloves as effective protection. We run a extra training session for LOR10 users to clean with DMSO.

We also separate EBL and optical resist spinning. Most of our optical resists are acetone/IPA compatible. We have no problem cleaning S1813, AX20x0, and AZ10XT from the same spin bowl with them. Some spinner drain designs are more prone to clogging than others if provoked.

BR, Owain

From: labnetwork <labnetwork-bounces at mtl.mit.edu> On Behalf Of Dan P. Woodie
Sent: 19 February 2025 17:22
To: labnetwork at mtl.mit.edu
Subject: Re: [labnetwork] Photoresist and Ebeam Resist In Same Spinner?

CAUTION: This e-mail originated outside the University of Southampton.
The other consideration is your bowl cleaning protocols after each spin. Some resists will precipitate when mixed with common cleaning solvents like acetone or PGMEA / ethyl lactate, which can make cleaning harder or if your bowl has a drain, can lead to a clogged line. So even typical "photoresist-like" materials such as PGMI based LOR, which is in a different solvent than most photoresists, can be an issue to mix. At Cornell we developed solvent "classes" based on this sensitivity to precipitate and grouped spinners to avoid clogged drain lines. A lot of grad students will assume acetone will dissolve everything...

Now if you don't rinse your bowls with solvent to clean the spun off resist down a drain, that mixing may not be an issue.

Dan

Daniel Woodie
Director, Micro/Nano Fabrication Center, Princeton Materials Institute

From: labnetwork <labnetwork-bounces at mtl.mit.edu<mailto:labnetwork-bounces at mtl.mit.edu>> On Behalf Of Golan Tanami
Sent: Wednesday, February 19, 2025 9:25 AM
To: Grant Shao <shaog at stanford.edu<mailto:shaog at stanford.edu>>; labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>
Cc: Galina Chechelnitsky <galinac at savion.huji.ac.il<mailto:galinac at savion.huji.ac.il>>; yuval.yanushpolsk at mail.huji.ac.il<mailto:yuval.yanushpolsk at mail.huji.ac.il>; itzhak.shweky at mail.huji.ac.il<mailto:itzhak.shweky at mail.huji.ac.il>
Subject: Re: [labnetwork] Photoresist and Ebeam Resist In Same Spinner?

Hi Grant,

After consulting with my team cc'd here, there may be two possible reasons that perhaps facilitate this separation:


  1.  Avoiding potential contamination, ease of cleanup etc.
  2.  E-Beam resist is not sensitive to light, thus you'd prefer working under natural lighting conditions (i.e., white light), whereas photoresist (PR) is sensitive to white light (incl. UV) and this is why yellow lightning is a must. To avoid situations where one may bring PR coated wafer into E-beam spinner that works at the environment of white light, physical separation between the two is necessary.

Best,

Golan.



[cid:image001.jpg at 01DB8317.A4F7C7B0]
Golan A. Tanami, PhD | Head of the Unit for Nanofabrication (UNF)

Center for Nanoscience and Nanotechnology
Edmond J. Safra Campus
The Hebrew University of Jerusalem
T +972.2.6584179 | M +972.50.9891111
golant at savion.huji.ac.il<mailto:golant at savion.huji.ac.il>
Website: https://nano.huji.ac.il/UNF


From: labnetwork <labnetwork-bounces at mtl.mit.edu<mailto:labnetwork-bounces at mtl.mit.edu>> On Behalf Of Grant Shao
Sent: Wednesday, February 19, 2025 4:27 AM
To: labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>
Subject: [labnetwork] Photoresist and Ebeam Resist In Same Spinner?

Hello Labnetwork,

I'm wondering if there's a chemical reason for having dedicated spinners to keep photoresist and ebeam resist separated. I think quite a few of the university nanofabs do this, but wondering what the rationale is. Is there some sort of chemical reaction that makes it more likely to contaminate or harder to clean up?

Thanks,
Grant

--
Grant Shao
Nanofabrication Operations Manager
Stanford Nano Shared Facilities<http://snsf.stanford.edu/>

shaog at stanford.edu<mailto:shaog at stanford.edu> | 650.441.9042
Spilker Building, Room 004
348 Via Pueblo
Stanford, CA 94305-4088
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