<div dir="auto">Attached is a paper that mentions and cites the reference regarding Ta pellet addition. We have good success with this method in a crucible. </div><div dir="auto"><br></div><div dir="auto">(Thank you Tom Reynolds for sharing that, and for reading this mailing list even after your retirement!)<br clear="all"><br clear="all"><div dir="auto"><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><font face="georgia, serif" size="4" style="font-family:georgia,serif;color:rgb(0,0,0)">-- Demis </font><font face="georgia, serif" size="1" style="font-family:georgia,serif;color:rgb(0,0,0)">(<a href="https://wiki.nanotech.ucsb.edu/wiki/Demis_D._John" target="_blank" style="font-family:georgia,serif">contact info</a>)</font><div><i style="font-family:"times new roman",serif">Reminder</i><span style="font-family:"times new roman",serif">: The NanoFab has a </span><a href="https://wiki.nanotech.ucsb.edu/wiki/Frequently_Asked_Questions#Publications_acknowledging_the_Nanofab" style="font-family:"times new roman",serif" target="_blank">publications policy</a><font face="georgia, serif" size="4" style="font-family:georgia,serif;color:rgb(0,0,0)"><br></font></div></div></div></div></div><div><br></div><div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Sat, Feb 1, 2025 at 07:43 Demis D. John <<a href="mailto:demis@ucsb.edu">demis@ucsb.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;padding-left:1ex;border-left-color:rgb(204,204,204)"><div dir="auto">Adding a tantalum pellet to the Au source will getter the carbon and reduce spitting. </div><div dir="auto"><br></div><div dir="auto">I can’t quite find the original paper, but here are some web pages that reference it:</div><div dir="auto">1)</div><div dir="auto"><div><a href="https://compoundsemiconductor.net/article/116629/Tackling_the_foot#:~:text=concern.-,The%20combination%20of%20the%20crucible%20liner%20and%20tantalum%20%E2%80%98getters%E2%80%99%20looks%20like%20a%20win%2Dwin:%20the%20deposition%20rate%20increases%20while%20reducing%20gold%20spitting.,-But" target="_blank">https://compoundsemiconductor.net/article/116629/Tackling_the_foot#:~:text=concern.-,The%20combination%20of%20the%20crucible%20liner%20and%20tantalum%20%E2%80%98getters%E2%80%99%20looks%20like%20a%20win%2Dwin:%20the%20deposition%20rate%20increases%20while%20reducing%20gold%20spitting.,-But</a></div><div dir="auto"><br></div><div dir="auto">2)</div><div dir="auto"><div><a href="https://www.memsnet.org/memstalk/16896/#:~:text=look%20for%20a%20paperwritten%20in%20the%201970s%20that%20suggests%20adding%20a%20small%20piece%20of%20tantalum%20to%20yourgold.%20%20The%20Ta%20will%20not%20melt%20but%20it%20will%20control%20the%20spitting." target="_blank">https://www.memsnet.org/memstalk/16896/#:~:text=look%20for%20a%20paperwritten%20in%20the%201970s%20that%20suggests%20adding%20a%20small%20piece%20of%20tantalum%20to%20yourgold.%20%20The%20Ta%20will%20not%20melt%20but%20it%20will%20control%20the%20spitting.</a></div><br></div><br clear="all">I don’t have measurements of carbon contamination with this - although we do this in our e-beam evaporators. </div><div dir="auto"><br clear="all"><div dir="auto"><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><font face="georgia, serif" size="4" style="font-family:georgia,serif;color:rgb(0,0,0)">-- Demis </font><font face="georgia, serif" size="1" style="font-family:georgia,serif;color:rgb(0,0,0)">(<a href="https://wiki.nanotech.ucsb.edu/wiki/Demis_D._John" style="font-family:georgia,serif" target="_blank">contact info</a>)</font><div><i style="font-family:"times new roman",serif">Reminder</i><span style="font-family:"times new roman",serif">: The NanoFab has a </span><a href="https://wiki.nanotech.ucsb.edu/wiki/Frequently_Asked_Questions#Publications_acknowledging_the_Nanofab" style="font-family:"times new roman",serif" target="_blank">publications policy</a><font face="georgia, serif" size="4" style="font-family:georgia,serif;color:rgb(0,0,0)"><br></font></div></div></div></div></div><div><br></div><div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sat, Feb 1, 2025 at 05:17 Czwakiel, James <<a href="mailto:czwakj@rpi.edu" target="_blank">czwakj@rpi.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;padding-left:1ex;border-left-color:rgb(204,204,204)">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div dir="ltr">Youry</div>
<div dir="ltr"><br>
</div>
<div dir="ltr">Once contamination is detected…. Clean clean clean</div>
<div dir="ltr">All metal covers removed and blasted and ultra sonically cleaned </div>
<div dir="ltr">Plus …. Make sure crucibles are not touched even with gloved hands….. always use tweezers</div>
<div dir="ltr"><br>
</div>
<div dir="ltr">
<p style="font-size:12pt;text-decoration:none;font-family:Aptos,sans-serif;margin:0px;line-height:1.5;color:rgb(33,33,33)">
<span style="font-family:Aptos,sans-serif">James Czwakiel</span></p>
<p style="font-size:12pt;text-decoration:none;font-family:Aptos,sans-serif;margin:0px;line-height:1.5;color:rgb(33,33,33)">
<span style="font-family:Aptos,sans-serif">Semiconductor Equipment Engineer</span></p>
<p style="font-size:12pt;text-decoration:none;font-family:Aptos,sans-serif;margin:0px;line-height:1.5;color:rgb(33,33,33)">
<img src="cid:ii_194c22c5cf5e4e40a5f1" alt="Image" style="width:225px;max-width:100%"></p>
<br>
</div>
<div dir="ltr"><br>
</div>
</div>
</div>
<div id="m_6477205361056948293m_7999255587210345344ms-outlook-mobile-signature">
<div dir="ltr"><br>
</div>
Get <a href="https://aka.ms/o0ukef" target="_blank">Outlook for iOS</a></div>
</div>
<hr style="display:inline-block;width:98%">
<div id="m_6477205361056948293m_7999255587210345344divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(0,0,0)"><b style="font-family:Calibri,sans-serif">From:</b> labnetwork <<a href="mailto:labnetwork-bounces@mtl.mit.edu" style="font-family:Calibri,sans-serif" target="_blank">labnetwork-bounces@mtl.mit.edu</a>> on behalf of Youry Borisenkov <<a href="mailto:yb2471@columbia.edu" style="font-family:Calibri,sans-serif" target="_blank">yb2471@columbia.edu</a>><br>
<b style="font-family:Calibri,sans-serif">Sent:</b> Friday, January 31, 2025 11:59:09 AM<br>
<b style="font-family:Calibri,sans-serif">To:</b> Fab Network <<a href="mailto:labnetwork@mtl.mit.edu" style="font-family:Calibri,sans-serif" target="_blank">labnetwork@mtl.mit.edu</a>><br>
<b style="font-family:Calibri,sans-serif">Subject:</b> [EXTERNAL][labnetwork] Gold e-beam deposition - carbon contamination</font>
<div> </div>
</div>
<div>
<div>
<p style="width:100%;border:1px solid rgb(156,101,0);padding:2pt;background-color:rgb(255,235,156)">
<b>CAUTION:</b> This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.</p>
</div></div></div><div><div>
<div>
<div dir="ltr">
<div>Hi All and happy Friday,</div>
<div>I know it is a topic that has been discussed multiple times, however, I'm still lacking a solution that works and will appreciate you sharing your experience.</div>
<div><br>
</div>
<div>Currently we are using a Fabmate crucible, and getting some carbon contamination . </div>
<div>For clean Gold layers we use thermal evaporation. The films are good but it requires a lot of gold.</div>
<div><br>
</div>
<div>So far we tried using a Molybdenum crucible with and without a spacer. The issue with this approach was that eventually after some time, we get carbon contamination back. I believe it's present in the chamber and eventually a critical mass is built on
top of the gold in the crucible, coming from the chamber.</div>
<div><br>
</div>
<div>Were anyone successful in overcoming carbon contamination in their e-beam deposition overtime? </div>
<div>What are the procedures you are following? Maybe cleaning more frequently?</div>
<div><br>
</div>
<span>-- </span><br>
<div dir="ltr" data-smartmail="gmail_signature">
<div dir="ltr">
<div style="color:rgb(136,136,136)">Thank you,</div>
<div style="color:rgb(136,136,136)">Youry Borisenkov</div>
<div style="color:rgb(136,136,136)"><a href="https://cni.columbia.edu/columbia-university-clean-room" target="_blank">CNI</a></div>
<div style="color:rgb(136,136,136)">Columbia University</div>
<div style="color:rgb(136,136,136)">CEPSR 1017, New York, NY, 10027, United States.</div>
<div style="color:rgb(136,136,136)"><a href="https://sustainable.columbia.edu/crown-commuter" style="color:rgb(17,85,204)" target="_blank"><img src="https://sustainable.columbia.edu/sites/default/files/content/crown%20commuter%20badge_0.png" width="96" height="40"></a></div>
</div>
</div>
</div>
</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>
</blockquote></div></div>
</blockquote></div></div>