www.photomacrography.net :: View topic - 1999 AMI Wafer
www.photomacrography.net Forum Index
An online community dedicated to the practices of photomacrography, close-up and macro photography, and photomicrography.
Photomacrography Front Page Amateurmicrography Front Page
Old Forums/Galleries
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
1999 AMI Wafer
Goto page Previous  1, 2, 3
 
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Photography Through the Microscope
View previous topic :: View next topic  
Author Message
mawyatt



Joined: 22 Aug 2013
Posts: 1666
Location: Clearwater

PostPosted: Thu Mar 01, 2018 7:12 am    Post subject: Reply with quote

rjlittlefield wrote:
mawyatt wrote:
Of course you have the lens effect taking place at the chip surface with the index of refraction for the insulators hovering around 1.5.

I was wondering if the lower levels were somehow exposed, versus being seen through transparent stuff.

If I recall correctly, apparent depth goes as 1/RI, so 3 microns apparent at refractive index 1.5 would be actual depth 4.5 microns.

Your diagram shows about 10 microns.

That discrepancy strikes me as large enough to be interesting, but given the direct measurement method, not large enough to indicate an error. That judgement could change with more info, of course.

While I have you here, I have another question. In JW's images, the top layer of elements, oriented vertically in these images, seems to bump up-and-over the elements that are oriented horizontally. In the diagram that you've provided, I notice that the "metal 5" layer seems actually to be two sets of wires, with one crossing up and over the other. Is that perception correct?

--Rik


Since I don't have details on the AMI process, my comments are speculative.

Usually the individual metal layers are planarized during processing as they are "built up" by deposition, same for insulator layer. The last metal layer generally is not planarized nor is the final passivation layer, so you expect to see some vertical 3D effects with these layers.

As you mention, in James's images it shows what appears to be metal ridges in the lower layers as they go over other metal lines. I don't think these are actual ridges because of the mentioned layer planarization but an optical effect that caused by a different metal orientation that occurs during the metal deposition process. This might be caused by the metal grain boundaries getting oriented differently when the metal is deposited over another insulated layer that has a metal line underneath. Since the metal may have a slight different surface texture due to the grain boundary orientation it has a different optical micro reflectance.

Best,
_________________
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike


Last edited by mawyatt on Thu Mar 01, 2018 7:31 am; edited 1 time in total
Back to top
View user's profile Send private message
mawyatt



Joined: 22 Aug 2013
Posts: 1666
Location: Clearwater

PostPosted: Thu Mar 01, 2018 7:25 am    Post subject: Reply with quote

Smokedaddy wrote:
Thanks Mike. I dug this up this morning.





-JW:


James,

Your post popped up just before I posted Rik's response.

This is an experimental 0.35 micron MEMs process and not a standard CMOS production process.

It seems to confirm the depth being greater than 3 microns, as I get something ~7.8 microns from top to bottom, and ~7.2 microns from the top surface of the bottom metal to top of the passivation layer.

BTW how did you light the chip?

Best,
_________________
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
Back to top
View user's profile Send private message
Smokedaddy



Joined: 07 Oct 2006
Posts: 1187
Location: Phoenix, Arizona

PostPosted: Thu Mar 01, 2018 1:23 pm    Post subject: Reply with quote

mawyatt wrote:

BTW how did you light the chip?


The stereo image was done with epi illumination with a GIF filter then converted to monochrome in Photoshops Channel Mixer. I can't guarantee the steps were 333nm, nor the exact overall depth. It could of been 4um but I don't think so. I usually note that 'stuff' but didn't this time. The color images were epi Nomarski. The video I posted was with a Mirau Interferometer objective using my Nikon MM-11 with universal epi illuminator using bright field.

-JW:

Oops ... here's the link for the info I posted.

https://www.hindawi.com/journals/js/2010/937301/

Some interesting SEM images there too.
Back to top
View user's profile Send private message Visit poster's website
Smokedaddy



Joined: 07 Oct 2006
Posts: 1187
Location: Phoenix, Arizona

PostPosted: Thu Mar 01, 2018 5:47 pm    Post subject: Reply with quote

Thought I'd test the 28mm Schneider Kreuznach Componon before making a panorama. I probably won't use it. The areas circled in red are the areas I photographed and posted at the beginning of this thread.



-JW:
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Photography Through the Microscope All times are GMT - 7 Hours
Goto page Previous  1, 2, 3
Page 3 of 3

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group