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3X test - Objectives vs Lenses - Final Results Online
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RobertOToole



Joined: 17 Jan 2013
Posts: 1044
Location: United States

PostPosted: Sun Aug 26, 2018 9:38 am    Post subject: Reply with quote

Lou Jost wrote:
I really like that you included the Mag.X. It is good to see what is possible, not just what is practical or easy. I lust after that lens!


Its gets worse once you find one! Now I really want the 8x/0.32 version Mag.x!

Super APO, Double Telecentricity, f/1.4, effective 12.5 at 8x. The Mity 7.5 is f/2.1 and Eff 17.86!

The 8x/0.32 would be pretty awesome pushed down to 5x!

Robert
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RobertOToole



Joined: 17 Jan 2013
Posts: 1044
Location: United States

PostPosted: Sun Aug 26, 2018 9:47 am    Post subject: Reply with quote

ray_parkhurst wrote:
RobertOToole wrote:
...
The Metal markings look like they have a lot more depth than the poly marks.


Poly is below contact, which is below the metals. Poly and contact are both doped, so are quite thin, which is why the resolution is better. Metals are thick, so cannot be spaced as closely, and have worse resolution due to alignment, etching variation (under or over etching producing undercut or shorts), and grain boundary issues. Design rules for line spacings get larger as you go higher.


Thanks for the input Ray.

Any idea the difference in height could be between Poly and Metal?

If those are micron width markings, whats the height, fractions of a Nm?

I am a little surprised that the DOF of the Mity 50x got it all in one image.

Robert
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ray_parkhurst



Joined: 20 Nov 2010
Posts: 1722
Location: Santa Clara, CA, USA

PostPosted: Sun Aug 26, 2018 9:52 am    Post subject: Reply with quote

RobertOToole wrote:
ray_parkhurst wrote:
RobertOToole wrote:
...
The Metal markings look like they have a lot more depth than the poly marks.


Poly is below contact, which is below the metals. Poly and contact are both doped, so are quite thin, which is why the resolution is better. Metals are thick, so cannot be spaced as closely, and have worse resolution due to alignment, etching variation (under or over etching producing undercut or shorts), and grain boundary issues. Design rules for line spacings get larger as you go higher.


Thanks for the input Ray.

Any idea the difference in height could be between Poly and Metal?

If those are micron width markings, whats the height, fractions of a Nm?

I am a little surprised that the DOF of the Mity 50x got it all in one image.

Robert


Poly and Contact are sub-micron. Metals can be up to a couple microns thick but typically average around 1um. So if you have a 4-metal system, you're probably talking total height of a few um.
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mawyatt



Joined: 22 Aug 2013
Posts: 1664
Location: Clearwater

PostPosted: Sun Aug 26, 2018 10:00 am    Post subject: Reply with quote

Robert, Ray,

Sometimes processes have a thick and thin top metal, the thick is often used for inductors to improve the quality factor. The thick can be 5 microns.

During the era of this wafer we utilized a new process at Bell Labs that had a special thick gold top metal, it was 25 microns thick!! You can guess what it was used for!!

Best,
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ray_parkhurst



Joined: 20 Nov 2010
Posts: 1722
Location: Santa Clara, CA, USA

PostPosted: Sun Aug 26, 2018 10:09 am    Post subject: Reply with quote

mawyatt wrote:
Robert, Ray,

Sometimes processes have a thick and thin top metal, the thick is often used for inductors to improve the quality factor. The thick can be 5 microns.

During the era of this wafer we utilized a new process at Bell Labs that had a special thick gold top metal, it was 25 microns thick!! You can guess what it was used for!!

Best,


In my HEMT processes, we top-out around 3um thick for gold. As thickness increases, width and spacing rules must also increase, so these thick metals are only used for high current routing on the very top layers.

By appearance, the process for this wafer probably did not use thick metals, and likely only Al an alloy, so I'd still expect total thickness of only a few um at most.
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AlxndrBrg



Joined: 14 Jan 2014
Posts: 49

PostPosted: Mon Aug 27, 2018 6:44 am    Post subject: Reply with quote

Great stuff - I am kinda missing the Lomo 3,7x though, from what I recall it handles being pushed down quite far, would be interesting to see how it competes with these real glass monsters Wink
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Lou Jost



Joined: 04 Sep 2015
Posts: 2857
Location: Ecuador

PostPosted: Mon Aug 27, 2018 6:57 am    Post subject: Reply with quote

I've been using the Lomo on FF where it does very well (it is not so great on MFT). I tested it against the DiMage at 4x on FF and the Lomo won, even in the corners.
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ray_parkhurst



Joined: 20 Nov 2010
Posts: 1722
Location: Santa Clara, CA, USA

PostPosted: Wed Aug 29, 2018 10:00 am    Post subject: Reply with quote

AlxndrBrg wrote:
Great stuff - I am kinda missing the Lomo 3,7x though, from what I recall it handles being pushed down quite far, would be interesting to see how it competes with these real glass monsters Wink


I was wondering same thing. It should do well due to the low CA, though its NA 0.11 likely won't be competitive from raw resolution perspective. Same situation for the Inspec.x 105mm f4 3.5x lens with NA 0.1. Great coverage, low CAs, but won't beat the resolution of a high NA objective.
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