[labnetwork] Diamond Etching

[Martin, Michael]

Hi Emma,
    We've done quite a bit of diamond here at U. of Louisville.  We used to use our Trion ICP RIE but decided to switch to our deep reactive ion etcher (Oxford Estrelas) because it has a 5 kW power supply (I think) on the icp. We used an alumina mask deposited via ALD and have had some really good results.  I don't think there's a real concern of contamination here because the diamond is essentially just carbon and much of the reactor is made out of aluminum or aluminum oxide.  We did check with the manufacturer and they okayed aluminum oxide as a mask.  The film's etch very quickly at 20 degrees C and ICP at 2500W.  I'll talk to the person who did the etching to get some details.
    ALSO,  just yesterday at our NNCI conference we had a presentation from Oakridge and they mentioned etching diamond using a SEM in Loc Vac mode, i.e. with water vapor! So that may be a trick you should be aware of as it might be handy for producing nano-scale features.  Here's a paper I found https://iopscience.iop.org/article/10.1088/1361-6528/ab25fe

Regards,
   Michael
Patterning of diamond with 10 nm resolution by electron-beam-induced etching - IOPscience<https://iopscience.iop.org/article/10.1088/1361-6528/ab25fe>
Patterning of diamond with 10 nm resolution by electron-beam-induced etching, Vasilis Dergianlis, Martin Geller, Dennis Oing, Nicolas Wöhrl, Axel Lorke
iopscience.iop.org



________________________________
From: labnetwork <labnetwork-bounces at mtl.mit.edu> on behalf of Demis D. John <demis at ucsb.edu>
Sent: Wednesday, July 31, 2024 5:53 PM
To: Emma Anquillare <eanquillare at gc.cuny.edu>
Cc: Labnetwork (labnetwork at mtl.mit.edu) <labnetwork at mtl.mit.edu>
Subject: Re: [labnetwork] Diamond Etching

Some people who received this message don't often get email from demis at ucsb.edu. Learn why this is important<https://aka.ms/LearnAboutSenderIdentification>

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.

Emma,
I know some of our users run Cl2/O2 etches of Diamond, hours-long to get through ~50-100µm or so if I remember correctly.  No contaminations as far as I know.  We've even run it on our III-V etcher (just a few times) and not had any obvious process issues.
https://wiki.nanofab.ucsb.edu/wiki/Process_Group_-_Process_Control_Data#Oxford_PlasmaPro_Cobra_Etcher

Probably Ania Jayich's group at UCSB has some papers about this.
-- Demis (contact info<https://wiki.nanotech.ucsb.edu/wiki/Demis_D._John>)
Reminder: The NanoFab has a publications policy<https://wiki.nanotech.ucsb.edu/wiki/Frequently_Asked_Questions#Publications_acknowledging_the_Nanofab>


On Wed, Jul 31, 2024 at 1:07 PM Emma Anquillare <eanquillare at gc.cuny.edu<mailto:eanquillare at gc.cuny.edu>> wrote:
Hello Lab network!

We have a user that is interested in etching a CVD grown slab of Diamond (Area: 3mmx3mm) about ~300 um thick via CF4/O2 or SF6 plasma (CF4 process described here-
 https://www.sciencedirect.com/science/article/abs/pii/S0925963501006173<https://urldefense.com/v3/__https://www.sciencedirect.com/science/article/abs/pii/S0925963501006173__;!!GekbXoL5ynDpFgM!WxaE7hfA6-iCIfo3iRBj8F1Agt1XD-R1rG2Erff2xgbqNr8azLuLPVme0Bu1-MPWWvbxOATSjMfwV6cW23nVbunPXr7k$> , though they would use a SiO2/ PMMA instead of Al mask and an ICP instead of an RIE).

Here is what I have read on diamond so far:
There is no precedent category for Carbon or diamond in the Cornell CNF materials categories (though SiC was allowed in even the most restricted tools) or in labnetwork. The sputter yield should be very low (~0.2 with Xe at 750ev- though most of the other values we have for comparison were with Ar at 600eV) and I could not find a vapor pressure curve for it. MP/BP at atmosphere is absurdly high (in the thousands) and I don't think the etch temperature would be hot enough for it to degrade to graphite. (Actually- I don't even know if our etcher will get hot enough to prompt the fluorine reaction based on literature, but apparently it has been etched before.) Not a toxic material. We might get HF vapor as a side product but usually figure scrubbers can handle that without further risk or precautions.

Do any facilities out there have experience plasma etching CVD diamond? What level-of-cleanliness tool did you allow it in? Were there any contamination problems (especially relevant to waveguides) or other safety aspects I should be aware of? What cleaning recipe did you use?

Thanks,
Emma









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

[cid:ii_1910ac54523b30e1d8f1]
Catalyzing Change, Celebrating Gains:
A decade of visionary science for the public good.
_______________________________________________
labnetwork mailing list
labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>
https://mtl.mit.edu/mailman/listinfo.cgi/labnetwork
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240801/66fa263e/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Outlook-1t1zxbk1.jpg
Type: image/jpeg
Size: 141606 bytes
Desc: Outlook-1t1zxbk1.jpg
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240801/66fa263e/attachment.jpg>