[labnetwork] Defects after resist spinning

[Demis D. John]

We have seen something like this - but we never investigated further where
they came from, because yield was good enough even with these relatively
sparse spots.
Some looked like yours, others had even further delamination as pictured
below.

This was PR spun onto Gold, so I assumed that we had PR delaminating from
the Au or Au delaminating from the substrate. I believe we only noticed
them after develop, so at the time I hypothesized that the squiggly lines
are something like developer creeping under the resist.
However the jagged lines are indicative of thin-film stress, so it could
instead be the Au (I believe it was TiAu) delaminating from the substrate.
I imagine we had some relatively large, sparse particles on the wafer
before our TiAu EBeam deposition, which caused slight shadowing around
them.  Then either the PR solvent, or Stress from baking, or liquid
immersion developing caused delamination at those defects. Those are my
guesses.

I have this printed in my office - mistakes sometimes make excellent
pictures!
— Demis




On Fri, Oct 22, 2021 at 16:54 Eva Rose <eva.rose at gno.de> wrote:

> Dear all,
>
>
> did anybody  ever see any defects like this on the resist surface after
> resist spinning. The diameter varies from about 20um to over 150um.
>
>
>
>
>
>
> Any idea what the reason could be?
>
>
> Best regards,
>
> Eva
>
> _______________________________________________
> labnetwork mailing list
> labnetwork at mtl.mit.edu
> https://mtl.mit.edu/mailman/listinfo.cgi/labnetwork
>
-- 
-- Demis

----------------------------------------
*   Process Scientist Manager*
 *UCSB Nanofabrication Facility* <https://www.nanotech.ucsb.edu/>
         Demis' Contact Info
<https://wiki.nanotech.ucsb.edu/wiki/Demis_D._John>
----------------------------------------
*Reminder*: The NanoFab has a publications policy
<https://wiki.nanotech.ucsb.edu/wiki/Frequently_Asked_Questions#Publications_acknowledging_the_Nanofab>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20211023/dee7d220/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: ffhliaocjefcijah.bmp
Type: image/bmp
Size: 282906 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20211023/dee7d220/attachment.bmp>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image_50753025.JPG
Type: image/heic
Size: 2983767 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20211023/dee7d220/attachment.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: bgnaccaefkdljllg.bmp
Type: image/bmp
Size: 282906 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20211023/dee7d220/attachment-0001.bmp>