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<p class="MsoNormal">Agree with Jim. If after chamber clean and reconditioning, the problem still exists, check all the MFC and make sure there is no leak and calibrated. We ended up replaced one of the MFCs last spring to end the battle with black silicon
on our Unaxis DSE.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Jessie<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b>From:</b> labnetwork-bounces@mtl.mit.edu <labnetwork-bounces@mtl.mit.edu>
<b>On Behalf Of </b>Beall, James A. (Fed)<br>
<b>Sent:</b> Monday, July 27, 2020 4:52 PM<br>
<b>To:</b> Pallavi Sharma <pnsharma@unm.edu>; labnetwork@mtl.mit.edu<br>
<b>Subject:</b> Re: [labnetwork] Deep Reactive Ion Etch Problems<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">When we see that it often means you are overdue for chamber cleaning and reconditioning.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">For us (SPTS Pegasus 150 mm tool) that is a long O2 chamber clean with a wafer on the chuck) followed by running our standard Bosch process on bare silicon full wafers until they come out shiny.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">If that fails then you need manual chamber wall clean (iso and scotchbrite) followed by the above.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Best of luck,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Jim<o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="color:black">From:</span></b><span style="color:black">
<a href="mailto:labnetwork-bounces@mtl.mit.edu">labnetwork-bounces@mtl.mit.edu</a> <<a href="mailto:labnetwork-bounces@mtl.mit.edu">labnetwork-bounces@mtl.mit.edu</a>> on behalf of Pallavi Sharma <<a href="mailto:pnsharma@unm.edu">pnsharma@unm.edu</a>><br>
<b>Sent:</b> Monday, July 27, 2020 10:02 AM<br>
<b>To:</b> <a href="mailto:labnetwork@mtl.mit.edu">labnetwork@mtl.mit.edu</a> <<a href="mailto:labnetwork@mtl.mit.edu">labnetwork@mtl.mit.edu</a>><br>
<b>Subject:</b> [labnetwork] Deep Reactive Ion Etch Problems</span> <o:p></o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Hello all,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">I am having problem with anisotropic etching of silicon by Deep Reactive ion etch. Grass or black silicon is the issue all the time, attaching some of the SEM pictures of the sample. Every recipe
I tried to fine tune result in grass formation, even as the process initiates in tool wafer surface starts to turn brown and ultimately black. I tried varying SF6 gas flow, Bias power, Substrate temperature but every time I see is highly dense grass with no
clean surface. <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Any help will be greatly appreciated.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Thank you,<br>
Pallavi<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
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