<div><div dir="auto" style="font-size:1rem;word-spacing:1px;border-color:rgb(49,49,49);color:rgb(49,49,49)">Hi Kurt,</div><div dir="auto" style="font-size:1rem;word-spacing:1px;border-color:rgb(49,49,49);color:rgb(49,49,49)">We “forced” the <span class="term-highlighted" style="background-color:rgba(253,214,99,0.24)">Bismuth</span> users to try the “dirty” thermal evaporator for their process first. </div><div dir="auto" style="font-size:1rem;word-spacing:1px;border-color:rgb(49,49,49);color:rgb(49,49,49)">We make sure to deposit a 50-100 nm Ti film prior their deposition, a new boat and a new Bi material is always used and the users pump overnight when loading their samples, bringing the chamber pressure to high-8 mbar pressure range. So far they (and we) are happy. </div><div dir="auto" style="font-size:1rem;word-spacing:1px;border-color:rgb(49,49,49);color:rgb(49,49,49)">I got a negative feedback from the ebeam vendor with regards to <span class="term-highlighted" style="background-color:rgba(253,214,99,0.24)">Bismuth</span> deposition, since it’s such a low melting/vapor pressure point metal. It will be very hard to get rid of, because it will get on many unshielded surfaces. </div><div dir="auto" style="font-size:1rem;word-spacing:1px;border-color:rgb(49,49,49);color:rgb(49,49,49)">Theoretically you can get over this issue by encapsulating the Bi with thick Ti layer after Bi deposition in a shared ebeam tool, but luckily we didn’t have to test this theory. </div><div dir="auto" style="font-size:1rem;word-spacing:1px;border-color:rgb(49,49,49);color:rgb(49,49,49)"><br></div><div dir="auto" style="font-size:1rem;word-spacing:1px;border-color:rgb(49,49,49);color:rgb(49,49,49)"><b>So eventually we never tried it in the ebeam. </b></div><div dir="auto" style="font-size:1rem;word-spacing:1px;border-color:rgb(49,49,49);color:rgb(49,49,49)">I will be happy to hear from experience of someone who did, since we do get many requests for Bi, and I’m not sure for how long we will be able to keep accommodating these on the thermal evap. </div><div dir="auto" style="word-spacing:1px;border-color:rgb(49,49,49);color:rgb(49,49,49)"><br></div><div dir="auto" style="font-size:1rem;word-spacing:1px;border-color:rgb(49,49,49);color:rgb(49,49,49)">Hope that is helpful. </div><div dir="auto" style="word-spacing:1px;border-color:rgb(49,49,49);color:rgb(49,49,49)"><br></div><div dir="auto" style="font-size:1rem;word-spacing:1px;border-color:rgb(49,49,49);color:rgb(49,49,49)">Best,</div><div dir="auto" style="font-size:1rem;word-spacing:1px;border-color:rgb(49,49,49);color:rgb(49,49,49)">Youry CNI- Columbia University </div></div><div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Nov 11, 2022 at 3:42 PM Kurt Kupcho <<a href="mailto:kurt.kupcho@wisc.edu">kurt.kupcho@wisc.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)">
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<p class="MsoNormal">Hi Labnetwork<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">I am wondering if anyone out there allows the deposition of Bi in their ebeam evaporator and any potential problems it may cause related to safety or vacuum chamber contamination/particulate generation.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Bismuth as a solid material seems rather safe but I have no experience with it in PVD tools.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Any info or experiences you could share with me is much appreciated.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Thanks<u></u><u></u></p>
<p class="MsoNormal">Kurt <u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<div style="border-style:none none dotted;border-bottom-width:3pt;padding:0in 0in 1pt;border-bottom-color:windowtext">
<p class="MsoNormal" style="border:none;padding:0in"><u></u> <u></u></p>
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<p class="MsoNormal">Kurt Kupcho<u></u><u></u></p>
<p class="MsoNormal">Materials Science Engineer<u></u><u></u></p>
<p class="MsoNormal">Nanoscale Fabrication Center (NFC)<u></u><u></u></p>
<p class="MsoNormal">University of Wisconsin<u></u><u></u></p>
<p class="MsoNormal"><a href="https://www.google.com/maps/search/1550+Engineering+Dr?entry=gmail&source=g">1550 Engineering Dr</a>.<u></u><u></u></p>
<p class="MsoNormal">ECB 3110<u></u><u></u></p>
<p class="MsoNormal">Madison, WI 53706<u></u><u></u></p>
<p class="MsoNormal"><span lang="ES">E: </span><a href="mailto:kurt.kupcho@wisc.edu" target="_blank"><span lang="ES">kurt.kupcho@wisc.edu</span></a><span lang="ES"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="ES">T: 608-262-2982<u></u><u></u></span></p>
<p class="MsoNormal"><img border="0" src="cid:18468d5f779ad7999131" style="width:614px;max-width:100%"><u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
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