<div dir="ltr">Hi Emma,<div><br></div><div>To see what compounds I may have in the chamber, I use the "compounds" section of this link: <a href="https://ptable.com/#Compounds">https://ptable.com/#Compounds</a></div><div>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.</div><div><br></div><div>SA </div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, May 15, 2024 at 7:53 AM Wirth, Justin C <<a href="mailto:jcwirth@purdue.edu">jcwirth@purdue.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="msg3467678826546879052">





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<p class="MsoNormal">Hi Emma,<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">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
<a href="https://urldefense.com/v3/__https://purdue.atlassian.net/wiki/spaces/BNCWiki/pages/6246876/Tutorial*on*Etching*TutorialonEtching-GeneralMaterials-Willitetch*3F__;KysjJQ!!IBzWLUs!TANTwddpDwOfbj22F_YUpJEtqvljiVHzw7Z1iLBNvvrYiTz08eoNY0T9ifutauC6eyGzMMW23dZa00RKLcLjUQ$" target="_blank">
this</a> (reproduced below, not sure if it will come through or not) is a very rough starting point I’ve come up with that I think (hope) helps get in the ballpark. Would love to hear from other folks as to how they approach this.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal" style="margin-left:0.5in">Materials can generally be etched in the RIEs as long as they form volatile byproducts, or products for which the vapor pressure (at the temperature of the etch) is higher than the pressure of the chamber.<u></u><u></u></p>
<p class="MsoNormal" style="margin-left:0.5in"><b><u></u> <u></u></b></p>
<p class="MsoNormal" style="margin-left:0.5in"><b>Etching is very complicated and this will be massive oversimplification</b>...but generally volatile byproducts can be determined from literature, or as a fallback, the CRC Handbook of Chemistry and Physics Online,
 (4) Properties of the Elements & Inorganics, Physical Constants of Inorganic Compounds: <a href="https://urldefense.com/v3/__https://hbcp.chemnetbase.com/faces/documents/04_02/04_02_0001.xhtml__;!!IBzWLUs!TANTwddpDwOfbj22F_YUpJEtqvljiVHzw7Z1iLBNvvrYiTz08eoNY0T9ifutauC6eyGzMMW23dZa00S9rICseA$" target="_blank">https://hbcp.chemnetbase.com/faces/documents/04_02/04_02_0001.xhtml</a>. 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.<u></u><u></u></p>
<p class="MsoNormal" style="margin-left:0.5in"><u></u> <u></u></p>
<p class="MsoNormal" style="margin-left:0.5in">As a VERY general rule of thumb, anything with a boiling point (t_bp) < 185 C will be volatile in the ICP RIEs.<u></u><u></u></p>
<p class="MsoNormal" style="margin-left:0.5in"><u></u> <u></u></p>
<p class="MsoNormal" style="margin-left:0.5in">As an example, aluminum chloride is volatile, and aluminum fluoride and aluminum are not.<u></u><u></u></p>
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<p class="MsoNormal" style="margin-left:0.5in"><u></u> <u></u></p>
<p class="MsoNormal" style="margin-left:0.5in">Neither Copper chloride or copper fluoride is volatile, which is why it is not allowed in any chamber:<u></u><u></u></p>
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<p class="MsoNormal" style="margin-left:0.5in"><u></u> <u></u></p>
<p class="MsoNormal" style="margin-left:0.5in">Byproducts of silicon are very volatile:<u></u><u></u></p>
<p class="MsoNormal" style="margin-left:0.5in"><img border="0" width="1574" height="32" style="width: 16.3958in; height: 0.3333in;" id="m_3467678826546879052Picture_x0020_21" src="cid:ii_18f7c99e0ff20fef51c"><u></u><u></u></p>
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<p class="MsoNormal" style="margin-left:0.5in"><u></u> <u></u></p>
<p class="MsoNormal" style="margin-left:0.5in">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:<u></u><u></u></p>
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<p class="MsoNormal" style="margin-left:0.5in"><img border="0" width="1583" height="29" style="width: 16.4895in; height: 0.302in;" id="m_3467678826546879052Picture_x0020_17" src="cid:ii_18f7c99e0ff2484d5510"><u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal" style="background:repeat white"><span style="color:black;border:1pt windowtext;padding:0in">Thanks,<u></u><u></u></span></p>
<p class="MsoNormal" style="background:repeat white"><span style="color:black;border:1pt windowtext;padding:0in">Justin<u></u><u></u></span></p>
<p class="MsoNormal" style="background:repeat white"><span style="color:black;border:1pt windowtext;padding:0in"><u></u> <u></u></span></p>
<p class="MsoNormal" style="background:repeat white"><span style="color:black;border:1pt windowtext;padding:0in">Justin C. Wirth, PhD </span><span style="color:black"><u></u><u></u></span></p>
<p class="MsoNormal" style="background:repeat white"><span style="color:black;border:1pt windowtext;padding:0in">Senior Research Engineer – EBL Processes & Nanofab Process Consultation </span><span style="color:black"><u></u><u></u></span></p>
<p class="MsoNormal" style="background:repeat white"><span style="color:black;border:1pt windowtext;padding:0in">Birck Nanotechnology Center | Room 2287A<br>
765.494.8203 | </span><span style="color:black"><a href="mailto:jcwirth@purdue.edu" target="_blank"><span style="color:rgb(5,99,193);border:1pt windowtext;padding:0in">jcwirth@purdue.edu</span></a><span style="border:1pt windowtext;padding:0in"> </span><u></u><u></u></span></p>
<p class="MsoNormal" style="background:repeat white"><span style="color:black"><a href="https://urldefense.com/v3/__https://purdue.atlassian.net/wiki/spaces/BNCWiki__;!!IBzWLUs!TANTwddpDwOfbj22F_YUpJEtqvljiVHzw7Z1iLBNvvrYiTz08eoNY0T9ifutauC6eyGzMMW23dZa00SOT9T6ag$" target="_blank"><span style="color:rgb(5,99,193);border:1pt windowtext;padding:0in">BNCWiki</span></a> |
<a href="https://urldefense.com/v3/__https://purdue.ilabsolutions.com/__;!!IBzWLUs!TANTwddpDwOfbj22F_YUpJEtqvljiVHzw7Z1iLBNvvrYiTz08eoNY0T9ifutauC6eyGzMMW23dZa00T7I8wVQg$" target="_blank"><span style="color:rgb(5,99,193)">Purdue iLab</span></a> |
<a href="https://urldefense.com/v3/__https://outlook.office.com/bookwithme/user/5ad94572a9c04a4e8aa9159479128868@purdue.edu?anonymous&ep=plink__;!!IBzWLUs!TANTwddpDwOfbj22F_YUpJEtqvljiVHzw7Z1iLBNvvrYiTz08eoNY0T9ifutauC6eyGzMMW23dZa00Tyx7nbGQ$" target="_blank">
<span style="color:rgb(5,99,193)">Book time on my calendar</span></a><u></u><u></u></span></p>
<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal"><b>From:</b> labnetwork <<a href="mailto:labnetwork-bounces@mtl.mit.edu" target="_blank">labnetwork-bounces@mtl.mit.edu</a>> <b>
On Behalf Of </b>Emma Anquillare<br>
<b>Sent:</b> Friday, May 10, 2024 12:07 PM<br>
<b>To:</b> <a href="mailto:labnetwork@mtl.mit.edu" target="_blank">labnetwork@mtl.mit.edu</a><br>
<b>Subject:</b> [labnetwork] Predicting Solid Etch Products<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<span style="font-size:9pt;font-family:wf_segoe-ui_normal;color:rgb(33,33,33)">You don't often get email from
<a href="mailto:eanquillare@gc.cuny.edu" target="_blank">eanquillare@gc.cuny.edu</a>. <a href="https://urldefense.com/v3/__https://aka.ms/LearnAboutSenderIdentification__;!!IBzWLUs!TANTwddpDwOfbj22F_YUpJEtqvljiVHzw7Z1iLBNvvrYiTz08eoNY0T9ifutauC6eyGzMMW23dZa00RjgrJ9kQ$" target="_blank">
Learn why this is important</a><u></u><u></u></span></p>
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<b>External Email</b>: Use caution with attachments, links, or sharing data ----<u></u><u></u></span></p>
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<p class="m_3467678826546879052elementtoproof"><span style="font-size:12pt;font-family:Aptos;color:black">Dear Lab network,</span><u></u><u></u></p>
<p><span style="font-size:12pt;font-family:Aptos;color:black"> </span><u></u><u></u></p>
<p class="m_3467678826546879052elementtoproof"><span style="font-size:12pt;font-family:Aptos;color:black">First time caller here
</span><span style="font-size:12pt;font-family:"Segoe UI Emoji",sans-serif;color:black">😊</span><span style="font-size:12pt;font-family:"Segoe UI Emoji",sans-serif;color:black"> </span><u></u><u></u></p>
<p class="m_3467678826546879052elementtoproof"><u></u> <u></u></p>
<p class="m_3467678826546879052elementtoproof"><span style="font-size:12pt;font-family:Aptos;color:black">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.</span><u></u><u></u></p>
<p class="m_3467678826546879052elementtoproof"><u></u> <u></u></p>
<p class="m_3467678826546879052elementtoproof"><span style="font-size:12pt;font-family:Aptos;color:black">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?</span><u></u><u></u></p>
<p><span style="font-size:12pt;font-family:Aptos;color:black"> </span><u></u><u></u></p>
<p class="m_3467678826546879052elementtoproof"><span style="font-size:12pt;font-family:Aptos;color:black">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.</span><u></u><u></u></p>
<p class="m_3467678826546879052elementtoproof"><u></u> <u></u></p>
<p><span style="font-size:12pt;font-family:Aptos;color:black">Best,</span><u></u><u></u></p>
<p><span style="font-size:12pt;font-family:Aptos;color:black">Emma</span><u></u><u></u></p>
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<p class="MsoNormal"><b><span style="font-size:12pt;font-family:Aptos;color:black">_____________________________________________</span></b><span style="font-size:12pt;font-family:Aptos;color:black"><u></u><u></u></span></p>
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<p class="MsoNormal"><b><span style="font-size:12pt;font-family:Aptos;color:black">Emma Anquillare, PhD</span></b><span style="font-size:12pt;font-family:Aptos;color:black"><u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:12pt;font-family:Aptos;color:black">Research Scientist<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:12pt;font-family:Aptos;color:black">ASRC
<span style="background:repeat white">Nanofabrication Facility</span></span><span style="font-family:Aptos;color:black"><u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:12pt;font-family:Aptos;color:black;background:repeat white">City University of New York</span><span style="font-size:12pt;font-family:Aptos;color:black"><u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:12pt;font-family:Aptos;color:black"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span style="font-size:12pt;font-family:Aptos;color:black"><img border="0" width="337" height="77" style="width: 3.5104in; height: 0.802in;" id="m_3467678826546879052image_0" src="cid:ii_18f7c99e0fe4ce8e91"></span><span style="font-size:12pt;font-family:Aptos;color:black"><u></u><u></u></span></p>
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<p class="MsoNormal"><i><span style="font-size:12pt;font-family:Aptos;color:black">Catalyzing Change, Celebrating Gains: </span></i><span style="font-size:12pt;font-family:Aptos;color:black"><u></u><u></u></span></p>
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<p class="MsoNormal"><i><span style="font-size:12pt;font-family:Aptos;color:black">A decade of visionary science for the public good.</span></i><span style="font-size:12pt;font-family:Aptos;color:black"><u></u><u></u></span></p>
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</div></blockquote></div><br clear="all"><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div dir="ltr"><div><div style="color:rgb(136,136,136)"><span style="font-size:12.8px">Mohsen (Sam) Azadi</span></div><div style="color:rgb(136,136,136)"><span style="font-size:12.8px">Principal Scientist</span></div><div style="color:rgb(136,136,136)"><span style="font-size:12.8px">Quattrone Nanofabrication Facility</span><br></div><div style="color:rgb(136,136,136)"><span style="font-size:12.8px">Singh Center for Nanotechnology</span></div><div style="color:rgb(136,136,136)">University of Pennsylvania</div><div style="color:rgb(136,136,136)">3205 Walnut St. <span style="font-size:12.8px">Room 116</span><br></div><div style="color:rgb(136,136,136)">Philadelphia, PA 19104</div></div><div>-------------------------------------</div><div>Pronouns: he/him/his</div></div></div></div>