[labnetwork] Copper Through-Glass Vias on fused silica

[J_Hagopian at comcast.net]

I think we are only looking to deposit only 1 or 2 microns..is that right Larry?

John
Sent from my iPhone

> On Feb 26, 2025, at 5:07 PM, Hathaway, Malcolm R <hathaway at cns.fas.harvard.edu> wrote:
> 
> 
> Hi Larry,
> 
> As it happens, Cu is not an established ALD process yet (that I am aware of).
> 
> 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!
> 
> Which is to say, ALD is slow.  
> 
> Typical films are under 200nm.
> 
> 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.
> 
> 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.
> 
> I'm happy to chat about this off-line if you like.  Hopefully others with proper electroplating experience will chime in shortly.
> 
> 
> Mac
> Harvard CNS
> 
> 
> From: labnetwork <labnetwork-bounces at mtl.mit.edu> on behalf of Hess, Larry A. (GSFC-5530) <larry.hess-1 at nasa.gov>
> Sent: Wednesday, February 26, 2025 9:36 AM
> To: labnetwork at mtl.mit.edu <labnetwork at mtl.mit.edu>
> Subject: [labnetwork] Copper Through-Glass Vias on fused silica
>  
> Hi,
> I am looking for a (hopefully established) source to deposit ALD copper on Though-Glass Vias.
> The vias are about 20um in diameter with an aspect ratio of about 10:1.
> 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.
>  
> Thanks for your help!
>  
> Larry
>  
> Larry A. Hess, PhD
> NASA
> Goddard Space Flight Center
> 8800 Greenbelt Road
> Code 553, Detector Systems Branch
> Building 11, Room E011
> Greenbelt, MD 20771
> 301-286-0259 (P)
> 301-286-1672 (F)
>  
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