[labnetwork] Predicting Solid Etch Products

Wed May 15 10:22:28 EDT 2024

Hi Emma,

To see what compounds I may have in the chamber, I use the "compounds"
section of this link: https://ptable.com/#Compounds
You can just drag and drop the primary elements in the box in the middle,
and on the left you'll see a list of all possible and known compounds that
have the selected elements. You can start by looking at the boiling point
of the ones that may exist inside the chamber, and as Justin said, as a
rule of thumb consider the ones with Tbp < 185 C as volatile.

SA

On Wed, May 15, 2024 at 7:53 AM Wirth, Justin C <jcwirth at purdue.edu> wrote:

> Hi Emma,
>
>
>
> This is a very good question, and one that I’ve struggled to answer as
> well. I’m not an etch expert but by necessity have had to try to answer
> some of these questions, and this
> <https://urldefense.com/v3/__https://purdue.atlassian.net/wiki/spaces/BNCWiki/pages/6246876/Tutorial*on*Etching*TutorialonEtching-GeneralMaterials-Willitetch*3F__;KysjJQ!!IBzWLUs!TANTwddpDwOfbj22F_YUpJEtqvljiVHzw7Z1iLBNvvrYiTz08eoNY0T9ifutauC6eyGzMMW23dZa00RKLcLjUQ$>
> (reproduced below, not sure if it will come through or not) is a very rough
> starting point I’ve come up with that I think (hope) helps get in the
> ballpark. Would love to hear from other folks as to how they approach this.
>
>
>
> Materials can generally be etched in the RIEs as long as they form
> volatile byproducts, or products for which the vapor pressure (at the
> temperature of the etch) is higher than the pressure of the chamber.
>
>
>
> *Etching is very complicated and this will be massive oversimplification*...but
> generally volatile byproducts can be determined from literature, or as a
> fallback, the CRC Handbook of Chemistry and Physics Online, (4) Properties
> of the Elements & Inorganics, Physical Constants of Inorganic Compounds:
> https://hbcp.chemnetbase.com/faces/documents/04_02/04_02_0001.xhtml
> <https://urldefense.com/v3/__https://hbcp.chemnetbase.com/faces/documents/04_02/04_02_0001.xhtml__;!!IBzWLUs!TANTwddpDwOfbj22F_YUpJEtqvljiVHzw7Z1iLBNvvrYiTz08eoNY0T9ifutauC6eyGzMMW23dZa00S9rICseA$>.
> From there, click "Go to Interactive Table", and find products that may be
> formed (i.e. chloride, fluorides, oxides, depending on the gasses). A
> compound is deemed volatile if it has a boiling point at a reasonable
> temperature range for the temperature and pressure of the system. Note that
> at lower pressures, boiling points decrease, so these are just a good
> starting point reference.
>
>
>
> As a VERY general rule of thumb, anything with a boiling point (tbp) <
> 185 C will be volatile in the ICP RIEs.
>
>
>
> As an example, aluminum chloride is volatile, and aluminum fluoride and
> aluminum are not.
>
>
>
> Neither Copper chloride or copper fluoride is volatile, which is why it is
> not allowed in any chamber:
>
>
>
> Byproducts of silicon are very volatile:
>
>
>
> Many times different fluorides/chlorides of the same material will have
> drastically different boiling points. It's important to research which will
> be formed in the plasma. Titanium is a good example of this, with TiCl2
> and TiCl3 being non-volatile, and TiCl4 being volatile:
>
>
>
>
>
> Thanks,
>
> Justin
>
>
>
> Justin C. Wirth, PhD
>
> Senior Research Engineer – EBL Processes & Nanofab Process Consultation
>
> Birck Nanotechnology Center | Room 2287A
> 765.494.8203 | jcwirth at purdue.edu
>
> BNCWiki
> <https://urldefense.com/v3/__https://purdue.atlassian.net/wiki/spaces/BNCWiki__;!!IBzWLUs!TANTwddpDwOfbj22F_YUpJEtqvljiVHzw7Z1iLBNvvrYiTz08eoNY0T9ifutauC6eyGzMMW23dZa00SOT9T6ag$>
> | Purdue iLab
> <https://urldefense.com/v3/__https://purdue.ilabsolutions.com/__;!!IBzWLUs!TANTwddpDwOfbj22F_YUpJEtqvljiVHzw7Z1iLBNvvrYiTz08eoNY0T9ifutauC6eyGzMMW23dZa00T7I8wVQg$>
> | Book time on my calendar
> <https://urldefense.com/v3/__https://outlook.office.com/bookwithme/user/5ad94572a9c04a4e8aa9159479128868@purdue.edu?anonymous&ep=plink__;!!IBzWLUs!TANTwddpDwOfbj22F_YUpJEtqvljiVHzw7Z1iLBNvvrYiTz08eoNY0T9ifutauC6eyGzMMW23dZa00Tyx7nbGQ$>
>
>
>
> *From:* labnetwork <labnetwork-bounces at mtl.mit.edu> * On Behalf Of *Emma
> Anquillare
> *Sent:* Friday, May 10, 2024 12:07 PM
> *To:* labnetwork at mtl.mit.edu
> *Subject:* [labnetwork] Predicting Solid Etch Products
>
>
>
> You don't often get email from eanquillare at gc.cuny.edu. Learn why this is
> important
> <https://urldefense.com/v3/__https://aka.ms/LearnAboutSenderIdentification__;!!IBzWLUs!TANTwddpDwOfbj22F_YUpJEtqvljiVHzw7Z1iLBNvvrYiTz08eoNY0T9ifutauC6eyGzMMW23dZa00RjgrJ9kQ$>
>
> ---- *External Email*: Use caution with attachments, links, or sharing
> data ----
>
>
>
> Dear Lab network,
>
>
>
> First time caller here 😊
>
>
>
> I am new to plasma etching, and working to institute better process
> control in our ICP and RIE etchers in an academic shared use facility. We
> don’t have the capacity to designate a single etcher for each process, so
> between our three tools, we essentially have a most-restricted, somewhat
> restricted, and “dirty” tool. To avoid cross contamination and chamber
> residue buildup, we have a technician manually scrub out the chambers with
> IPA every week- usually seeing the most solid residue in our ICP that
> handles Lithium Niobate milling.
>
>
>
> My question is- while many products of etch reactions get pumped away as
> vapors, what about the reactions that do leave solid residues? Is there a
> systematic way to predict or look up what solids will be left from common
> (or unusual) reactions, and know how they will react and interact with
> other solids and gasses present in your chamber? Especially with such
> frequent manual cleaning, how do you ensure that you don’t inadvertently
> open the chamber to something acutely toxic, pyrophoric, shock sensitive,
> etc?
>
>
>
> Very curious to learn what steps people take and tools they use
> (literature? calculations? databases? forums?)  when approaching this
> problem, and when asked to allow a new material into a tool.
>
>
>
> Best,
>
> Emma
>
>
>
> *_____________________________________________*
>
> *Emma Anquillare, PhD*
>
> Research Scientist
>
> ASRC Nanofabrication Facility
>
> City University of New York
>
>
>
> *Catalyzing Change, Celebrating Gains: *
>
> *A decade of visionary science for the public good.*
> _______________________________________________
> labnetwork mailing list
> labnetwork at mtl.mit.edu
>
> https://urldefense.com/v3/__https://mtl.mit.edu/mailman/listinfo.cgi/labnetwork__;!!IBzWLUs!TANTwddpDwOfbj22F_YUpJEtqvljiVHzw7Z1iLBNvvrYiTz08eoNY0T9ifutauC6eyGzMMW23dZa00Sz0F4lnw$
>

-- 
Mohsen (Sam) Azadi
Principal Scientist
Quattrone Nanofabrication Facility
Singh Center for Nanotechnology
University of Pennsylvania
3205 Walnut St. Room 116
Philadelphia, PA 19104
-------------------------------------
Pronouns: he/him/his
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.jpg
Type: image/jpeg
Size: 141606 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.png
Type: image/png
Size: 10436 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image003.png
Type: image/png
Size: 11185 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0001.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image004.png
Type: image/png
Size: 9552 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image005.png
Type: image/png
Size: 9109 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0003.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image006.png
Type: image/png
Size: 8407 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0004.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image007.png
Type: image/png
Size: 10144 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0005.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image008.png
Type: image/png
Size: 8057 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0006.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image009.png
Type: image/png
Size: 8693 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0007.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image010.png
Type: image/png
Size: 8631 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0008.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image011.png
Type: image/png
Size: 9702 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0009.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image012.png
Type: image/png
Size: 9804 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0010.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image013.png
Type: image/png
Size: 8875 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0011.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image014.png
Type: image/png
Size: 9844 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0012.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image015.png
Type: image/png
Size: 9531 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0013.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image016.png
Type: image/png
Size: 9762 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240515/847b5f35/attachment-0014.png>