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<span style="font-size:12pt" class="ContentPasted0 elementToProof">Is there any real safety information on these substitutes, or it's just that they are not as common as TMAH hence not regulated? I cannot find as much as a proper SDS on
</span>any of these. <br>
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Remember, TMAH was considered pretty benign until 2005-2010ish when 3 fatal accidents were brought up (hence quoted 75% mortality - 3 out of 4 for major exposure. Along with 20 minor chemical burns in the same dataset). Even then TMAH is a low priority for
toxicological research with mostly anecdotal evidence... <br>
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Mike</div>
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<p style="font-size:11pt; font-family:Calibri,sans-serif; margin:0"><span>_______________________________________________<br>
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<p style="font-size:11pt; font-family:Calibri,sans-serif; margin:0"><span>Michael Yakimov</span></p>
<p style="font-size:11pt; font-family:Calibri,sans-serif; margin:0"><span>Research scientist</span></p>
<p style="font-size:11pt; font-family:Calibri,sans-serif; margin:0"><span>College of Nanoscale Science and Engineering</span></p>
<p style="font-size:11pt; font-family:Calibri,sans-serif; margin:0"><span>SUNY Polytechnic Institute</span></p>
<p style="font-size:11pt; font-family:Calibri,sans-serif; margin:0"><span> </span></p>
<p style="font-size:11pt; font-family:Calibri,sans-serif; margin:0"><span>253 Fuller rd.
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<p style="font-size:11pt; font-family:Calibri,sans-serif; margin:0"><span>Albany NY 12203</span></p>
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<p style="font-size:11pt; font-family:Calibri,sans-serif; margin:0"><span>Phone: 518-437-8609 lab</span></p>
<p style="font-size:11pt; font-family:Calibri,sans-serif; margin:0"><span>e-mail: yakimom@sunypoly.edu</span></p>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> labnetwork <labnetwork-bounces@mtl.mit.edu> on behalf of Hathaway, Malcolm R <hathaway@cns.fas.harvard.edu><br>
<b>Sent:</b> Thursday, June 15, 2023 2:20 PM<br>
<b>To:</b> Labnetwork Mailing List <labnetwork@mtl.mit.edu><br>
<b>Subject:</b> [labnetwork] TMAH alternatives</font>
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Hello Labnetworkers,</div>
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Has anyone tried one of the TMAH substitutes that have become available?</div>
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How do they work? Are your users satisfied with their results?</div>
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For background, TMAH (tetramethylammonium hydroxide) is widely used in commercial resist developers (3%) and for HSQ developing (25%). In its 25% concentration, TMAH is a potent contact neurotoxin, which is fatal roughly 75% of the time, for exposures greater
than 7.5% of body area. Nasty stuff.<br>
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Several companies now have safer alternatives available, which we'd like to try out, such as:</div>
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<font class="x_ContentPasted0" face="Times New Roman,Times,serif">Envure 3330</font> (Sachem Chemical),
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E-Grade THEMAH SLM ((hydroxyethyl) methylammonium hydroxide, from Huntsman Chemical), and</div>
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Novo-safe SE-33 (ethyl tri-methy ammonium hydroxide from Transene).</div>
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We are particularly interested in using one of these as an HSQ developer, so we can do away with 25% TMAH.<br>
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Any experiences, good or bad, will be most welcome. <br>
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Thanks,</div>
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Mac Hathaway</div>
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Senior Process and Systems Engineer</div>
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Harvard Center for Nanoscale Systems<br>
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