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<p class="MsoNormal"><span style="color:#1F497D">Hi Shiva,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I believe we’ve had a thread on this subject in the last year or so. Can someone remind me how to find the old/archived threads (or do we just look in our email history)?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Past that, we have had this several different times on a couple different evaporators, almost always with Ti/Au or Ni/Au … Assuming we’ve baked the PMMA sufficiently it appears to be heating, though we’ve tried
thermal dots alongside and not found very high temps. Our solution has been to slow the deposition rate and put a “wait” step in during thick Au, Ni, sometimes Pt steps. The rate we use is 1-2A/s in most cases and the wait times vary but are usually halfway
through the Au step. <o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Lastly, we have a lot of people working with piezoelectric materials and this happens sometimes with those. That’s a separate topic. I’m assuming you are working with more “standard” semiconductor substrates
and the issue is caused by the metal/PMMA not the substrate itself?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Feel free to reach out to me off-line at
<a href="mailto:price.798@osu.edu">price.798@osu.edu</a> if you want more details. We did a lot of work with this at two different times, about 3 years ago and 10 years ago. We even had students travel back to UlUC to use their evaporator when we were diagnosing
this issue the first time.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Best of luck.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Aimee<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> labnetwork-bounces@mtl.mit.edu [mailto:labnetwork-bounces@mtl.mit.edu]
<b>On Behalf Of </b>Shivakumar Bhaskaran<br>
<b>Sent:</b> Wednesday, April 05, 2017 10:03 PM<br>
<b>To:</b> LabNet (labnetwork@mtl.mit.edu)<br>
<b>Subject:</b> [labnetwork] Blisters on PMMA resists<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif"">Hi All,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif"">We are getting blisters or metal film peeling off when depositing metals (Ti/Au/Al) on PMMA resists using EBeam Evaporation.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif"">Did anyone had this issue in your EBeam Evaporation tool. If so how did you fix this?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif"">-thanks<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif"">-Shiva<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif"">SNSF<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Times New Roman","serif";color:#4472C4"><a href="http://snsf.stanford.edu/">http://snsf.stanford.edu/</a><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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