<div dir="ltr">Hi Larry,<div><br></div><div>I'll reach out to you from my Veeco email. Long story short is that we have established processes for PE-ALD of Cu, other thermal processes for Ru / Pt to use as seed layers prior to Cu electroplating.</div><div><br></div><div>We also typically do a SiO2 / TiN deposition prior to this to act as an adhesion and barrier layer.</div><div><br></div><div>Lot of experience with this - shouldn't be an issue.</div><div><br></div><div>Best,</div><div><br></div><div>Eric</div><div><br></div><div><br></div><div><br></div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Wed, Feb 26, 2025 at 5:06 PM Hathaway, Malcolm R <<a href="mailto:hathaway@cns.fas.harvard.edu">hathaway@cns.fas.harvard.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="msg3532350801017765596">
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Hi Larry,</div>
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As it happens, Cu is not an established ALD process yet (that I am aware of).</div>
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Pt is common, but for your purposes (filling a 20um diameter hole) Pt would likely too expensive. In fact, ALD is probably not a viable option because you will need a layer slightly thicker than the radius of the hole (i.e. 10 um) and ALD of almost anything
in a 10um thickness will take 2-3 weeks (at least in our systems). We tend to speak of dep thickness/cycle (~1A) because to speak of rate in thickness/min is too embarrassing!</div>
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Which is to say, ALD is slow. </div>
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Typical films are under 200nm.</div>
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Material-wise, Pt, Ru, and some other conductors are available, but they tend to be on the (even) slower side. Some newer systems will get cycle times down to achieve 20-30 cy/min, but still nothing approaching CVD growth rates.</div>
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A Pt liner (or other conductive material) with Cu electroplating is much closer to a standard process for this sort of thing. And if you wanted to get fancy you could even consider selective W CVD, but that would require a bit of process development.</div>
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I'm happy to chat about this off-line if you like. Hopefully others with proper electroplating experience will chime in shortly.</div>
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Mac</div>
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Harvard CNS</div>
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<div id="m_-8561097841109263301divRplyFwdMsg" dir="ltr"><span style="font-family:Calibri,sans-serif;font-size:11pt;color:rgb(0,0,0)"><b>From:</b> labnetwork <<a href="mailto:labnetwork-bounces@mtl.mit.edu" target="_blank">labnetwork-bounces@mtl.mit.edu</a>> on behalf of Hess, Larry A. (GSFC-5530) <<a href="mailto:larry.hess-1@nasa.gov" target="_blank">larry.hess-1@nasa.gov</a>><br>
<b>Sent:</b> Wednesday, February 26, 2025 9:36 AM<br>
<b>To:</b> <a href="mailto:labnetwork@mtl.mit.edu" target="_blank">labnetwork@mtl.mit.edu</a> <<a href="mailto:labnetwork@mtl.mit.edu" target="_blank">labnetwork@mtl.mit.edu</a>><br>
<b>Subject:</b> [labnetwork] Copper Through-Glass Vias on fused silica</span>
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<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">Hi,</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">I am looking for a (hopefully established) source to deposit ALD copper on Though-Glass Vias.</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">The vias are about 20um in diameter with an aspect ratio of about 10:1.</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">I would also consider Cu electroplating( after an appropriate ALD adhesion/base layer), but I’m not sure how feasible that is given the via diameter and aspect ratio.</p>
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<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">Thanks for your help!</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt"> </p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">Larry</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt"> </p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">Larry A. Hess, PhD</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">NASA</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">Goddard Space Flight Center</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">8800 Greenbelt Road</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">Code 553, Detector Systems Branch</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">Building 11, Room E011</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">Greenbelt, MD 20771</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">301-286-0259 (P)</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt">301-286-1672 (F)</p>
<p style="margin:0in;font-family:Calibri,sans-serif;font-size:11pt"> </p>
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