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Hi Long,</div>
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One metric for how much those scratches actually matter is your helium leak rate with a wafer installed. Do you find it's been drifting up over the years, even with fresh wafers?</div>
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Regarding cleaning, if you're comfortable with removing the electrode I would recommend using IPA with a scotch-brite sanding pad (green), then finish with an ultra fine scotch brite polishing pad (gray). I'd recommend against doing this with the electrode
installed, as IPA could easily carry debris into the wafer lift/helium cooling channel.</div>
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It looks like your system is an Oxford, and they also sell replacement electrodes. We replace ours about once a decade in our Cl2/BCl3 ICP RIE.</div>
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Best,</div>
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<p style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(32, 31, 30); background-color: rgb(255, 255, 255)">
<span style="font-family: calibri, arial, helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgba(0, 0, 0, 0);">Sean Rinehart (he, him, his)</span></p>
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<span style="font-family: calibri, arial, helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgba(0, 0, 0, 0);">Assistant Director, Cleanroom Operations</span></p>
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<span style="font-family: calibri, arial, helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgba(0, 0, 0, 0);">Yale University</span></p>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> labnetwork-bounces@mtl.mit.edu <labnetwork-bounces@mtl.mit.edu> on behalf of Chang, Long <lvchang@Central.UH.EDU><br>
<b>Sent:</b> Friday, July 17, 2020 4:54 PM<br>
<b>To:</b> labnetwork@mtl.mit.edu <labnetwork@mtl.mit.edu><br>
<b>Subject:</b> [labnetwork] RIE Lower Electrode Question</font>
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<div class="" style="word-wrap:break-word; line-break:after-white-space">Hi All,
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<div class="">The lower electrode to our RIE system has taken quite a bit of abuse over the decade, see photo. There are scratches and pits caused by wafer shards. There’s also a film of something (probably PTFE oil) in the middle.</div>
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<div class="">Does anyone know how these scratches and pits might affect the Bosch Process? Any recommendations for cleaning this up?</div>
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<div class="">Thanks,<br class="">
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Long</div>
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<img id="x_533768D0-6081-49C3-B6B7-86CF797B26EE" class="" style="max-width: 100%; height: auto;" data-outlook-trace="F:1|T:1" src="cid:CEAD01E3-468C-431D-A3F3-56276537FAEC@serc.dhcp.e.uh.edu"></div>
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