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<p style="margin-top:0;margin-bottom:0">Ron, </p>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px;">1. F in an etch chamber from previous etch runs can slow down a Cl2 etching process. This is of most concern to III-V users. So for a well-controlled Cl2 etch process you want to get
all the F based polymers out of the chamber. </div>
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<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px;">2. In Poly Si etching C2F6, CF4 or NF3 are often used to remove surface oxides before start the HBr / Cl2 Si etch.</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px;"><br>
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<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px;">3. " Small amounts of CF4 (5-10 sccm) are added to the standard BCl3/Cl2/N2 process for residue removal. In some cases (particularly for copper residue), CF4 appears to widen the process
window for residue control.CF4 typically helps to eliminate open field residue, but there have been cases where CF4 helped with dense area residue as well. Since the addition of another gas introduces more variables to the process, the use ofCF4 should be
minimized." From old AMT Metal (Al) Etch Process Manual </div>
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<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px;"> In the Stanford Nanofabrication Facility (SNF) we have F containing gases in all our Cl2 etchers. Our Cl2 Si etchers have CF4 and C2F6. Our ICP metal etcher has CF4, and Our III-V etcher
has SF6. </div>
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<p>James (Jim) McVittie, Ph.D.</p>
<p>Senior Research Engineer</p>
<p>Electrical Engineering</p>
<p>Stanford University</p>
<p><span style="color:rgb(34,34,34); font-family:arial,sans-serif; font-size:13px; line-height:21.4933338165283px">336x Paul G. Allen Bldg</span></p>
<p><span style="color:rgb(34,34,34); font-family:arial,sans-serif; font-size:13px; line-height:21.4933338165283px">420 Via Palou Mall </span></p>
<p><span style="color:rgb(34,34,34); font-family:arial,sans-serif; font-size:13px; line-height:21.4933338165283px">Stanford, CA 94305</span><br>
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<p><span style="color:rgb(34,34,34); font-family:arial,sans-serif; font-size:13px; line-height:21.4933338165283px">mcvittie@stanford.edu</span></p>
<p><span style="color:rgb(34,34,34); font-family:arial,sans-serif; font-size:13px; line-height:21.4933338165283px">650-725-3640</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-bounces@mtl.mit.edu <labnetwork-bounces@mtl.mit.edu> on behalf of Reger, Ronald K <rreger@purdue.edu><br>
<b>Sent:</b> Thursday, November 8, 2018 10:45 AM<br>
<b>To:</b> labnetwork@mtl.mit.edu<br>
<b>Subject:</b> [labnetwork] Mixing Fluorine and Chlorine Chemistries</font>
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<p class="x_MsoNormal"><span style="font-size:14.0pt">Dear Colleagues,</span></p>
<p class="x_MsoNormal"><span style="font-size:14.0pt"> </span></p>
<p class="x_MsoNormal"><span style="font-size:14.0pt">Here at the Birck Nanotechnology Center we have a Panasonic E620 RIE ICP etcher that uses a variety of gases for etching of various materials. It has capability to do both chlorine-based and fluorine-based
processes. This has given us a lot of versatility for a wide variety of materials. We’re now exploring the implications of using both chemistries in the same etcher, particularly when it comes to making electron devices.
</span></p>
<p class="x_MsoNormal"><span style="font-size:14.0pt"> </span></p>
<p class="x_MsoNormal"><span style="font-size:14.0pt">We had done a small survey of a few other facilities and are finding a mixed response….. some facilities use dedicated etchers to keep these chemistries separated while others have both gases in the same
etcher and use one type of recipe or the other. Particularly for electron devices are there cross-contamination issues/models with using both gases in the same chamber? What would be the failure physics/mechanisms from this? If both chemistries are used
in the same system are there standard protocols between switching etch chemistries that we need to follow?</span></p>
<p class="x_MsoNormal"><span style="font-size:14.0pt"> </span></p>
<p class="x_MsoNormal"><span style="font-size:14.0pt">Any advice would be greatly appreciated as we’re getting into more electron device processing!</span></p>
<p class="x_MsoNormal"><span style="font-size:14.0pt"> </span></p>
<p class="x_MsoNormal"><span style="font-size:14.0pt">Thanks,<br>
Ron</span></p>
<p class="x_MsoNormal"><b><span style="font-size:12.0pt; font-family:"Microsoft PhagsPa",sans-serif"> </span></b></p>
<p class="x_MsoNormal"><b><span style="font-size:12.0pt; font-family:"Microsoft PhagsPa",sans-serif"> </span></b></p>
<p class="x_MsoNormal"><b><span style="font-size:14.0pt; font-family:"Microsoft PhagsPa",sans-serif">Ron Reger</span></b></p>
<p class="x_MsoNormal"><i><span style="font-size:10.0pt">Engineering Manager</span></i><i><span style="font-size:10.0pt"></span></i></p>
<p class="x_MsoNormal"><span style="font-size:9.0pt">Birck Nanotechnology Center | Room 2289 |<b></b></span></p>
<p class="x_MsoNormal"><b><span style="font-size:9.0pt">Office:</span></b><span style="font-size:9.0pt">
<span style="color:#0070C0">765.494.6667 </span>| <b>Email:</b> <span style="color:#0070C0">
<a href="mailto:rreger@purdue.edu" id="LPlnk752018" class="OWAAutoLink" previewremoved="true"><span style="color:#0070C0">rreger@purdue.edu</span></a></span></span></p>
<p class="x_MsoNormal">Wiki: <span style="color:#0070C0"><a href="https://wiki.itap.purdue.edu/display/BNCWiki" id="LPlnk828453" class="OWAAutoLink" previewremoved="true"><span style="color:#0070C0">https://wiki.itap.purdue.edu/display/BNCWiki</span></a></span></p>
<p class="x_MsoNormal">iLabs: <span style="color:#0070C0"><a href="https://purdue.ilabsolutions.com/homepage/" id="LPlnk689837" class="OWAAutoLink" previewremoved="true"><span style="color:#0563C1">https://purdue.ilabsolutions.com/homepage/</span></a></span></p>
<p class="x_MsoNormal"><span style="font-size:9.0pt; font-family:"Corbel",sans-serif">______________________________________________________________</span></p>
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