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You're referring to the fact that the edges aren't really sharp and are kind of 'soft', right? Like, everything isn't 90 degree angles and is kinda rippley in

You're referring to the fact that the edges aren't really sharp and are kind of 'soft', right? Like, everything isn't 90 degree angles and is kinda rippley in places? If so, that's not an SEM issue, that's just what it looks like. Photo exposure by it's very nature doesn't edge things 100% properly, diffraction or tiny misalignments causes stuff to end up being 'soft'. Also, keep in mind that was from 1997. Fab tech has gotten way better; although we don't have a scale reference, I imagine if you were to make the same device on modern tech everything would look a lot 'sharper'. You still can't get away from some softness though.

bogomipz 7y ago
>"You're referring to the fact that the edges aren't really sharp and are kind of 'soft', right? Like, everything isn't 90 degree angles and is kinda rippley in places?" Yes to both of these questions. "Soft" is probably a better way to articulate this, thanks. I'm not following the explanation of this being caused by photography however. Is this specific to photography at this scale? >"I imagine if you were to make the same device on modern tech everything would look a lot 'sharper." I don't have an example handy however I have seen more recent micrographs and they display the same "softness" and lack of true 90 degree angles etc.
- marcosdumay 7y ago
  > Is this specific to photography at this scale? Yes. A smaller scale makes it worse, a larger scale makes it better. If you reduce things enough, everything will become so blurred that you won't be able to see anything (that's why we can't photograph atoms using visible light), and if you make things large enough your camera will become the bottleneck so a very small amount of blur is added to any object, whatever the size.
  - bogomipz 7y ago
    Ah I see, when you say "photo" you are referring to the photolithography used in the chip making and not the captured photo of the finished chip is that correct?
    - marcosdumay 7y ago
      I mean the captured photography of the chip. Most of the time it is not done with ultraviolet light or electron microscopes, just with normal visible light cameras ans some very good lenses.
- Kirby64 7y ago
  By photography, I meant the photolithography, as you mentioned to another replier. This inherently will cause softness as described since there's always going to be light leakage and the masks you use will never be truly perfect. Given the sizes though, they're pretty damn good. As for 'modern tech' vs. old tech, I'm referring to if you made the same size silicon structure on newer tech. When you get down to 7nm or whatever, the same problems show up (or even new ones) because the sizes get smaller. I wouldn't be surprised if the image from 1997 is 180nm or larger nodes. Also, unlike the other replier, I don't think there's any meaningful diffraction (causing softness) by the actual SEM images... they don't use glass lenses like traditional cameras.
  - bogomipz 7y ago
    Thanks for the clarification. Agreed, given the scale of these they're pretty damn good :) Cheers.
deleted 7y ago
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bogomipz 7y ago

>"You're referring to the fact that the edges aren't really sharp and are kind of 'soft', right? Like, everything isn't 90 degree angles and is kinda rippley in places?" Yes to both of these questions. "Soft" is probably a better way to articulate this, thanks. I'm not following the explanation of this being caused by photography however. Is this specific to photography at this scale? >"I imagine if you were to make the same device on modern tech everything would look a lot 'sharper." I don't have an example handy however I have seen more recent micrographs and they display the same "softness" and lack of true 90 degree angles etc.

marcosdumay 7y ago
> Is this specific to photography at this scale? Yes. A smaller scale makes it worse, a larger scale makes it better. If you reduce things enough, everything will become so blurred that you won't be able to see anything (that's why we can't photograph atoms using visible light), and if you make things large enough your camera will become the bottleneck so a very small amount of blur is added to any object, whatever the size.
- bogomipz 7y ago
  Ah I see, when you say "photo" you are referring to the photolithography used in the chip making and not the captured photo of the finished chip is that correct?
  - marcosdumay 7y ago
    I mean the captured photography of the chip. Most of the time it is not done with ultraviolet light or electron microscopes, just with normal visible light cameras ans some very good lenses.
Kirby64 7y ago
By photography, I meant the photolithography, as you mentioned to another replier. This inherently will cause softness as described since there's always going to be light leakage and the masks you use will never be truly perfect. Given the sizes though, they're pretty damn good. As for 'modern tech' vs. old tech, I'm referring to if you made the same size silicon structure on newer tech. When you get down to 7nm or whatever, the same problems show up (or even new ones) because the sizes get smaller. I wouldn't be surprised if the image from 1997 is 180nm or larger nodes. Also, unlike the other replier, I don't think there's any meaningful diffraction (causing softness) by the actual SEM images... they don't use glass lenses like traditional cameras.
- bogomipz 7y ago
  Thanks for the clarification. Agreed, given the scale of these they're pretty damn good :) Cheers.

deleted 7y ago

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