[labnetwork] Dry Plasma Etch Cleaning Recipes and Evaluation

[Sun, Yong]

Hi Emma,

Here is what we have been doing to maintain a reasonably clean etching chamber  — we have an Oxford 100 ICP-RIE.

1. A standard 30min chamber cleaning recipe has 3 parts
    (i) 5min O2/Ar plasma at low plasma power for a gentle clean, with 80sccm O2 + 20sccm Ar, 30mtorr chamber pressure, 25W RF power + 500W ICP power. The purpose of this step is to gently remove some of the chamber residue before hitting it with a stronger plasma, so the initial reflected RF/ICP power won't spike up to cause alarms.
   (ii) 20min O2/SF6/Ar plasma at high plasma power for a deep clean, with 80sccm O2 + 20sccm Ar + 20sccm SF6, 30mtorr chamber pressure, 100W RF power + 1500W ICP power. The purpose of this step is to do a thorough cleaning of the residue accumulated in the chamber.
   (iii) 5min O2 plasma at low plasma power at the end, with 100sccm O2, 30mtorr chamber pressure, 25W RF power + 500W ICP power. The purpose of this step is to allow the electrostatic charges to dissipate, and remove any potential H2S residue on the wafer before unloading it to the loadlock.

If users' sample are sensitive to contamination (e.g. photonics), we typically vent the chamber, do a thorough physical cleaning of (i) the stage (ii) the chamber sidewall (iii) the interior of the ICP ceramic cylinder. We use IPA + Alphawipe to do most of the physical cleaning, if there is stubborn residue on the quartz clamp or the stage, then we do a gentle polishing with the scotch brite pad + IPA. The indication of a good clean chamber is that, following the cleaning process, the Alphawipe does not show any discoloration. After the physical cleaning, which typically takes 30min, we then run a full 30min chamber cleaning recipe to complete the service.

The above processes allow us to get decent etching results with an 18-year-old Oxford 100 ICP-RIE. Hope the information is helpful.

Best,

Yong Sun - Yale University Cleanroom
________________________________
From: labnetwork <labnetwork-bounces at mtl.mit.edu> on behalf of Martin, Michael <michael.martin at louisville.edu>
Sent: Wednesday, March 19, 2025 4:26 PM
To: Emma Anquillare <eanquillare at gc.cuny.edu>; Labnetwork (labnetwork at mtl.mit.edu) <labnetwork at mtl.mit.edu>
Subject: Re: [labnetwork] Dry Plasma Etch Cleaning Recipes and Evaluation

Hi Emma,
    Our go to method on our DRIE tools is just a relatively high power O2 clean for like 30 min at a kW or 2.  Although I was talking to our Oxford technician and he says occasionally it's necessary to mechanically clean these reactors with scotchbright followed by O2 clean.

-Michael

________________________________
From: labnetwork <labnetwork-bounces at mtl.mit.edu> on behalf of Emma Anquillare <eanquillare at gc.cuny.edu>
Sent: Monday, March 17, 2025 6:59 PM
To: Labnetwork (labnetwork at mtl.mit.edu) <labnetwork at mtl.mit.edu>
Subject: [labnetwork] Dry Plasma Etch Cleaning Recipes and Evaluation


CAUTION: This email originated from outside of our organization. Do not click links, open attachments, or respond unless you recognize the sender's email address and know the contents are safe.

Dear Labnetwork Hivemind,

I am looking to assemble what we know collectively about dry plasma etch cleaning recipes so that I can summarize, compare, and ultimately experimentally evaluate them.

I am interested in:
-Do your facility's etchers (ICP/ RIE) have custom clean recipes specific to certain etch recipes or materials? If so, what are they and what are both the recipe and clean parameters?
-Do you use an emission spectrometer (or any other method) to develop or evaluate these cleans?
-How did you come up with these cleans in the first place?
-Have you seen any good talks, literature, or other resources relevant to this subject?


Anything you can share is appreciated and (I hope) will be worth your efforts to provide, as I am seeking to compile this for public benefit.

Thanks!
Emma

_____________________________________________
Emma Anquillare, PhD
Research Scientist
ASRC Nanofabrication Facility
City University of New York

[cid:ab3ca695-ab87-43e4-9e5b-70612dfac19b]
Catalyzing Change, Celebrating Gains:
A decade of visionary science for the public good.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20250320/7187b66c/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Outlook-mzn1fp0b.jpg
Type: image/jpeg
Size: 141606 bytes
Desc: Outlook-mzn1fp0b.jpg
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20250320/7187b66c/attachment.jpg>