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It's just stunning how they have been able to achieve 7nm features. With a 193nm wavelength laser no less.
2. Immersion lithography (water as refractive index) + multiple patterning + computational lithography.
Also, IIRC SRAMs are just about the simplest blocks you can make, which means they're the simplest lithography wise. Simple blocks to make, so they're usually good candidates for exploration of new process...
7nm is hard (I've said in a previous post, but you're just fighting physics at that point, nevermind all the issues you start facing with crosstalk/etc), color me skeptical that they've really nailed down a "volume" process for doing it just yet.
I have a question - why does the fab machine lithographic printing etch out a half a chip on the edge of the wafer like in the article picture. I presume the wafers are a standard 300mm size, so is it just because the designers were too lazy to remove the half chips on the edges from their mask template designs ?
Aha I had a question too why wafers are round. The answer is Crystals form in a cylinder then sliced. https://en.wikipedia.org/wiki/Wafer_(electronics)#Formation . Sorry it doesn't answer your question but helped me. :)
I have a question - why does the fab machine lithographic printing etch out a half a chip on the edge of the wafer like in the article picture. I presume the wafers are a standard 300mm size, so is it just because the designers were too lazy to remove the half chips on the edges from their mask template designs ?
Earlier quoted context omitted.
ICs have just looked like mirrors for a while now. See this shot of a 14nm Vega die on the left and 28nm Fury die on the right: https://www.techpowerup.com/reviews/AMD/Radeon_RX_Vega_Previ...
I think you linked to a flip chip---you would expect a mirror finish from the bulk silicon side.
Earlier quoted context omitted.
Aha I had a question too why wafers are round. The answer is Crystals form in a cylinder then sliced. https://en.wikipedia.org/wiki/Wafer_(electronics)#Formation . Sorry it doesn't answer your question but helped me. :)
You could slice a cylinder the other way. That would give you rectangles, with the short dimension varying. I'm not so sure you'd save any space, but recycling the unused portion might be more reasonable to do.
In order to have uniform rectangular slices of the silicon crystal, you'd have to slice off horizontal cylinder segments. And that would defeat the purpose because if you just used circular wafers you'd have been able to get a couple dies out of that area.
It's just stunning how they have been able to achieve 7nm features. With a 193nm wavelength laser no less.
It’s not 7nm in any feature size it’s seceral times that. It’s achievable usually with multiple patterning and submersion 193nm wavelength in vacuum which goes to about 145 in water and they likely are using something other than water and you also have temperature which affects the refractive index.
So one of the most important questions when producing >10nm process is yield . In the article I can't really find yield numbers, and the only thing they mention is the SRAM chips getting "consistent double digits" -- so pessimistically consistently 10% yield. That's not "good" yield. Also, IIRC SRAMs are just about the simplest blocks you can make, which means they're the simplest lithography wise. Simple blocks to m…