Foreign object analysis of CMOS sensor via SEM/EDS

[Old School]

Hi All,
I was confused of about the failure analysis while I studying the foreign object on CMOS analysis.
Few un-identified objects were found in sensor surface after die/wire bonding.
Any comments on these objects are highly appreciated.

Thank you


All best,
Confused Engineer

 

[IRstuff]

What kind of sensor?

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[Old School]

A typical CMOS sensor

 

[IRstuff]

Do you really care? Contamination is contamination.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[hendersdc]

Are you sure this came from the wire bonding step? Could this be left over photoresist that didn't get washed off?

 

[btrueblood]

Or a flake of dead skin...

 

[mrfailure]

The analyses you presented suggests this is composed of nitrogen, sulfur, and calcium. It may well be organic but carbon is the overwhelming peak for exemplar and contaminant so you can't tell that way. Two things I would do is recollect the spectra down at about 8 keV to crank down the beam penetration, helping with contaminant identification. Semiquants are useful for this purpose of contaminant identification, but I would not include carbon at all - procedure notes carbon cannot be quantified due to its low atomic weight, so the numbers for it just confuses the issue.