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<p class="MsoNormal">Joe<o:p></o:p></p>
<p class="MsoNormal">Couple of options here:<o:p></o:p></p>
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<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">Vapor HF tools work well for mems structures where you need to etch SiO2 in the presence of Aluminum. Side note: PR doesn’t work as a mask for vapor HF either. Two manufacturers are:<o:p></o:p></li><ol style="margin-top:0in" start="1" type="a">
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level2 lfo1">Memsstar -
<a href="https://memsstar.com/mems-tools/vapor-hf-etching/">https://memsstar.com/mems-tools/vapor-hf-etching/</a> - We at UChicago have this tool.<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level2 lfo1">SPTS -
<a href="https://www.spts.com/categories/hf-vapor-release-etch">https://www.spts.com/categories/hf-vapor-release-etch</a><o:p></o:p></li></ol>
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">Transene Al Pad Etch will etch SiO2 and is designed to minimally etch Al (Ammonium Fluoride based etch). We have used this with a PR mask.
<o:p></o:p></li></ol>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;color:#1F497D">Thanks<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#1F497D">Peter J Duda</span><span style="font-size:13.5pt;font-family:"Segoe UI",sans-serif;color:black"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#1F497D">Technical Director, Pritzker Nanofabrication Facility<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Tahoma",sans-serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:maroon;background:white">Pritzker School of Molecular Engineering<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#1F497D">University of Chicago</span><span style="font-size:13.5pt;font-family:"Segoe UI",sans-serif;color:black"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#1F497D">5640 South Ellis Avenue</span><span style="font-size:10.0pt;color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#1F497D">ERC LL178<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#1F497D">Chicago, IL 60637</span><span style="font-size:13.5pt;font-family:"Segoe UI",sans-serif;color:black"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#1F497D">Office: 773-702-8903<br>
Pager/Text: 773-652-0480</span><span style="font-size:13.5pt;font-family:"Segoe UI",sans-serif;color:black"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#1F497D"><a href="mailto:duda@uchicago.edu">duda@uchicago.edu</a></span><span style="font-size:10.0pt;color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#1F497D">pme.uchicago.edu</span><span style="font-size:13.5pt;font-family:"Segoe UI",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b>From:</b> labnetwork <labnetwork-bounces@mtl.mit.edu> <b>
On Behalf Of </b>Maduzia, Joseph Walter<br>
<b>Sent:</b> Tuesday, October 26, 2021 3:49 PM<br>
<b>To:</b> labnetwork@mtl.mit.edu<br>
<b>Subject:</b> [labnetwork] Mask of Al in HF<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hello,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Does anyone have any suggestions for mask materials to protect Al in HF 49% for SiO2 removal in SOI wafer? The device is SOI, ICP DRIE etched to glass, HF etch to undercut and free devices, but have Al contact pads and AL is dep’d first.
Typically we use PR as pattern mask, but the Al is etching behind the PR. In this case the Al is deposited first, so although order of operations change might help, it’s not a good option atm.<o:p></o:p></p>
<p class="MsoNormal"><br>
Thank you for any suggestions you might have!<o:p></o:p></p>
<p class="MsoNormal"><b><span style="color:#13294B;text-transform:uppercase">JOE MADUZIA</span></b><span style="color:black"><br>
</span><i><span style="color:#13294B">MNMS Laboratory Specialist</span></i><span style="color:black"><br>
<br>
</span><span style="color:#13294B">The Grainger College of Engineering</span><span style="color:black"><br>
</span><span style="color:#13294B">Mechanical Science and Engineering</span><span style="color:black"><br>
<br>
</span><span style="color:#13294B">2239 Sidney Lu Mechanical Engineering Bldg</span><span style="color:black"><br>
</span><span style="color:#13294B">1206 W. Green<br>
Urbana, IL 61801</span><span style="color:black"><br>
</span><span style="color:#13294B">217.244.6302 | </span><a href="mailto:jmaduzi2@illinois.edu">jmaduzi2@illinois.edu</a><o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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