<div dir="ltr"><div dir="ltr">Hi Bob,<div><div>Thanks for sharing the case. I wonder if any conductive coating was used on top of the resist? When we do EBL on non-conductive substrates such as SiO2 or Si3N4, because they lack the intrinsic conductivity as Si wafers do, we typically need to use a layer of conductive coating on top, and use conductive tape to ground it to the stage. The aim is to avoid the electron accumulation on the chip during the e-beam writing, which is my suspicion on why your user's sample would have arcings - a lot of electrons go to the sample and will accumulate if there is no way out, resulting in a static charge that arcs later.</div><div>There is a commercial conductive coating product called "DisCharge" that can be spin-coated on top. Before switching to DisCharge, we also tried either a spin-coated layer of PEDOT:PSS or 10 nm of Cr layer, both can do the job if coated properly and the feature size is not too small. Maybe the user in your facility can give these a try if they want to do a quick verification. PEDOT:PSS might have some wetting issues during spin coating. DisCharge performs best overall and in theory will not affect feature resolution. The coating will go off when the developing and lift-off happens and should not leave any residual afterward. </div><div>Hope this info helps.</div><div><br></div><div>Best </div><div>Houpu</div><div> </div></div></div><span class="gmail_signature_prefix">--</span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div>----------------------------------------------</div><div>Houpu Li</div><div>Asst. Project Scientist. </div><div>Jack Baskin School of Engineering</div><div>UC Santa Cruz, California, USA</div><div><a href="mailto:hli322@ucsc.edu" target="_blank">hli322@ucsc.edu</a></div><div><a href="mailto:houpuli0@gmail.com" target="_blank">houpuli0@gmail.com</a></div><div>+1-4044229896</div><div><br></div></div></div><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, May 21, 2024 at 3:43 PM Geil, Bob <<a href="mailto:bob.geil@unc.edu" target="_blank">bob.geil@unc.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div>
<div dir="ltr">
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
Hello labnetwork,</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
I have a user that is fabricating some electrodes and has observed what appears to be arcing between the sharp points of the electrodes. Imagine features like this: > < where the distance between them is 2um - 8um. The substrate is quartz. Fabrication approach
is 1) ebeam lithography 2) ebeam evaporation and 3) lift-off.</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
After EBL development, the electrode circuit is open, as intended</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
After evaporation +lift-off, there is a line about few 100nms wide that is shorting the electrodes: >-<</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
There is not a short between the electrodes with the 8um gap, however, there are some metal lines extending from the two sides: >- -<</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
All of this suggests that arcing is occurring. Has anyone observed this before and can you suggest ways to get around it?</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
Thanks,</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
Bob</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<div id="m_-1657089056678446982m_4698660626797040697Signature">
<div style="font-family:Calibri,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<div dir="ltr" id="m_-1657089056678446982m_4698660626797040697divtagdefaultwrapper" style="font-size:12pt;font-family:Calibri,Helvetica,sans-serif;color:rgb(0,0,0)">
<div style="margin:0px;font-family:Arial,sans-serif;font-size:10pt;color:rgb(0,0,0)">
Bob Geil, PhD </div>
<div style="margin:0px;font-family:Arial,sans-serif;color:rgb(0,0,0)"><span style="font-size:10pt">Technical Director
</span><span style="font-size:13px">•</span><span style="font-size:10pt"> CHANL</span></div>
<div style="margin:0px;font-family:Arial,sans-serif;font-size:13px;color:rgb(0,0,0)">
Dept. of Chemistry • UNC-CH</div>
<div style="margin:0px;font-family:Arial,sans-serif;font-size:13px;color:rgb(0,0,0)">
Chapel Hill, NC </div>
<div style="margin:0px;font-family:Arial,sans-serif;font-size:13px;color:rgb(0,0,0)">
<br>
</div>
<div style="margin:0px;font-family:Arial,sans-serif;font-size:13px"><br>
</div>
<p style="margin:0px;font-family:Calibri,Helvetica,sans-serif,Helvetica,EmojiFont,"Apple Color Emoji","Segoe UI Emoji",NotoColorEmoji,"Segoe UI Symbol","Android Emoji",EmojiSymbols;font-size:16px">
<br>
</p>
</div>
</div>
</div>
_______________________________________________<br>
labnetwork mailing list<br>
<a href="mailto:labnetwork@mtl.mit.edu" target="_blank">labnetwork@mtl.mit.edu</a><br>
<a href="https://mtl.mit.edu/mailman/listinfo.cgi/labnetwork" rel="noreferrer" target="_blank">https://mtl.mit.edu/mailman/listinfo.cgi/labnetwork</a><br>
</div></blockquote></div><br clear="all"><div><br></div><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><br style="color:rgb(34,34,34)"></div></div></div>
</div>