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by shepting 2981 days ago
It's just stunning how they have been able to achieve 7nm features. With a 193nm wavelength laser no less.
5 comments

Yeah, you should take the fact they're not using EUV as the tremendous boulder of salt that it is: these are actually 10nm parts. Node names continue to be washed into Megahertz War-style naming schemes.

TSMC's process lines up pretty well with Intel's published numbers for their P1274 10nm process (Contacted Gate Pitch T & I: 54 nm, Minimum Metal Pitch T: 40nm I: 36 nm, High-Density SRAM bitcell size T: 0.027 µm^2 I: 0.0312 µm^2, etc).

What we've learned out of all of this is that Intel's struggles to push tooling towards EUV have benefited the industry at wide, as everyone's spent so much effort there that existing processes and tooling has become cheaper and faster to iterate. They've certainly fallen behind their all-time lead of almost two process generations, but they still appear to be about a generation (18-ish months) ahead of TSMC by published numbers.

But, who actually cares about the numbers, Marketing says 7nm so it's 7nm.

There's a big difference when you compare making 7nm features with about 100 process steps whereas EUV are doing it in like 4 steps.
EUV is still going to be 60+ steps.
7nm is really just a node name. Gate length is probably about 20nm. Still very impressive though!
The gate pitch is 54mm for TSMC and 56nm for Global Foundries @ 7nm.
That's the distance between gate midpoints, not their characteristic dimension.
> 54mm

Typo for nm, presumably :-).

The funny thing about 54mm is that this is pretty close to the original gate pitch, back when we had to use vacuum tubes or relays.
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.

Well... the article didn't say what the line width, say, actually is. It just said that the process is labeled 7nm, which doesn't necessarily correspond to any features actually being 7nm in size. It just means it's that much smaller than the previous process.

Don't get me wrong, it's still amazing, and the line widths are still going to be much less than 193 nm. I just wish they'd say what some standard feature size actually is.

1. Not really 7nm, only the fin width is ~7nm, metals, etc are more like 54nm.

2. Immersion lithography (water as refractive index) + multiple patterning + computational lithography.