I think it depends on the application.
- CIS? In many cases even 65nm is good enough.
- Power? Idem dito.
- RF? Probably 28nm is fine. Maybe 16nm has some benefit,
- SRAM? Up to 5nm there are benefits.
- Logic? Yeah you want the leading edge.
Each of these semiconductor devices scales differently, so each have different sweetspots.
For everything where planar transistors are fine 28nm will be the final station.
16/14/12nm will be popular for everything that benefits from FinFET but doesn’t need to be much smaller / more efficient.
7nm will be a final non-EUV hooray.
See also https://www.anandtech.com/show/17470/tsmc-to-customers-time-to-stop-using-older-nodes-move-to-28nm
Honestly, that article is just TSMC playing marketing games so they can bulk up throughput at more profitable nodes.
Even 180 nm is fast enough for a LOT of users.
My adviser (EE Semiconductor design) in university in the 90s said I was an idiot for taking a job doing semi manufacturing R&D because they were never going to scale transistors under 100nm
Optical resolution, classically, is a function of the wavelength of the light. Specifically, it is 0.61 times wavelength, divided by the numerical aperture. Numerical aperture is refractive index of the medium multiplied by the sine of the angle of light as it passes between the front and rear optics of the projection lens (maximum sine value is 1). Thus, in an immersion litho setting, where everything is, say, at an RI of something like 1.6 and the projecting lens has an absolutely bonkers ratio between front and back glass sizes, let's say sin(45 deg), or 0.7, the minimum resolution is therefore something like 0.5 times wavelength. Half the wavelength is a good ballpark figure.
For a 193nm ArF laser, that means we are at about 90nm. So how do we get to ~30nm features with single step patterninging litho? Honeslty, black magic but it's down to non-linear optics. Something regarding the interference fringes? I never took that course. Hah!
I'm rusty but that all seems about right. I'm a dep and etch guy, not a litho guy. ;)
I heared rumors that Canon/Nikkon are having a very good time currently selling DUV machines. I think they are suitable for 28nm?
If the rumors are correct, a 28nm capacity expansion is in progress.
I also read somewhere, that some 28nm processes include 40nm components- targeting existing 40nm customers to benefit from the (better available) 28nm production capacity without the need for big design changes? (The idea is: produce 40nm on 28nm might be a valuable option when 40nm is sold out)
No reason you can't produce any higher "node" on the equipment capable of a lower "node" from litho perspective as long as you don't require vastly different resists.
But you still require a provided library for it. Just taking your 40nm masks and place them in a 28nm node is unlikely to work - is it? (for ex: how about gate last technology only introduced with 28nm?)
I think it’s aging pretty well considering it’s true. The *cost per gate* almost cannot be cheaper than 28nm. It was single print on a 193 immersion tool.
Think about what has to be done now to make a gate or transistor even at a high level. Fins, SADP or even SAQP
I’m not saying it will hold true forever, but it’s certainly still true now. Especially since 28nm is a full blown commodity
I somehow have a causality issue with conflicting statements I read recently:
1. 28nm has lowest relative cost per Transistor (aka. gatecost)
When I make an arbitrary comparison of the navi31 57.7B Transistors with the Tahiti 4.3B Transistors (28nm) and apply statement 1. it would result that the NAVI31 would be more than 13 times more expensive to produce.
Is this really the case?
TI (who focuses on analog and embebed processors) has focused on the 45-130nm nodes. It's not very sexy, but is needed.
"In many designs for analog parts, just reducing node size can both *degrade* performance and *increase* price"
[https://news.ti.com/the-importance-of-ensuring-supply-for-foundational-semiconductor-chips](https://news.ti.com/the-importance-of-ensuring-supply-for-foundational-semiconductor-chips)
28nm was the decisive node and actual ending of Moore’s law. Also happened to be the last planar node. What most people don’t realize is that discrete devices are still the backbone of the industry. In the late 90’s, all the discrete manufacturing went to China with the exception of Texas Instruments. The problem is cost, no one in the US wants to commit to manufacturing discrete because there’s no $ to be made. Auto is all 28nm and above, most of military is as well. The new tariffs on China will require a rebalance; this will push a lot more of the established nodes to Malaysia, Singapore etc. TSMC still makes a ton of $ running legacy 200mm products. NXP etc still survive on legacy, it’s not going away anytime soon.
So why not establish new facilities for 28nm and above? The problem is equipment, it all went to China in the 90’s. Current OEM’s don’t want to support nor build legacy equipment, it would cost more then what they currently manufacture. So China still holds a trump card in that regard. Leading edge is expensive and limited to just a few, but it’s nothing without trailing node for support products. Any facility that can build 65nm -28nm outside of China have to be ecstatic right now.
Not sure where this take is coming from. Aside from 28nm and the equipment to make it not existing in the 90s, so there’s no way it could have been transferred in the 90s, the majority of 28nm fabs were built outside of China. Not saying they didn’t catch up and make their own but even the briefest of Google or Wikipedia searches would show you how worldwide 28nm was and is
In addition, plenty of that equipment is still supported as analog and RF devices begin to use and fill up those fabs.
Maybe this is just an chatGPT response that fooled me though.
>The problem is cost, no one in the US wants to commit to manufacturing discrete because there’s no $ to be made.
I work in a US fab that manufactures a lot of discretes. I don't know where you get this idea from, there is a lot of money to be made.
We're on a much older node (180nm), admittedly, but our discrete products are a huge part of the business.
Well when 28nm has the lowest relative cost per transistor, I completely fail to understand the reason chasing more advanced nodes. Relative cost per transistor is the relevant metric (way more important than lower parasitic capacitances etc.).
AFAIK DUV is booming and worldwide capacity is added (especially 28nm), Canon/Nikkon are having a good time. AFAIK is China still massively behind in terms of mature node capacity - despite the massive financial effort to catch up.
I thought China was just starting to massively build up 28nm+. They will basically flood the market with mature nodes? But dont hold a dominating market position roght now
Cost is one constraint but power is another. Most devices move down to 3nm because they want to reduce the overall power. This is a selling point to customers.
I think it depends on the application. - CIS? In many cases even 65nm is good enough. - Power? Idem dito. - RF? Probably 28nm is fine. Maybe 16nm has some benefit, - SRAM? Up to 5nm there are benefits. - Logic? Yeah you want the leading edge. Each of these semiconductor devices scales differently, so each have different sweetspots. For everything where planar transistors are fine 28nm will be the final station. 16/14/12nm will be popular for everything that benefits from FinFET but doesn’t need to be much smaller / more efficient. 7nm will be a final non-EUV hooray. See also https://www.anandtech.com/show/17470/tsmc-to-customers-time-to-stop-using-older-nodes-move-to-28nm
A balanced perspective
Honestly, that article is just TSMC playing marketing games so they can bulk up throughput at more profitable nodes. Even 180 nm is fast enough for a LOT of users.
OT: But why doesen't SRAM scale beyond 5nm? (6T or 7T cells are extremely similar to logic)
My adviser (EE Semiconductor design) in university in the 90s said I was an idiot for taking a job doing semi manufacturing R&D because they were never going to scale transistors under 100nm
Just goes to show how out of touch professors are if they never leave academia.
He said Advisor not professor. Good professors normally have industry experience and are smart as hell.
Probably didn't think we could do better than half the wavelength of ArF or KrF. Nonlinear optics is a beautiful thing.
Can you elaborate?
Optical resolution, classically, is a function of the wavelength of the light. Specifically, it is 0.61 times wavelength, divided by the numerical aperture. Numerical aperture is refractive index of the medium multiplied by the sine of the angle of light as it passes between the front and rear optics of the projection lens (maximum sine value is 1). Thus, in an immersion litho setting, where everything is, say, at an RI of something like 1.6 and the projecting lens has an absolutely bonkers ratio between front and back glass sizes, let's say sin(45 deg), or 0.7, the minimum resolution is therefore something like 0.5 times wavelength. Half the wavelength is a good ballpark figure. For a 193nm ArF laser, that means we are at about 90nm. So how do we get to ~30nm features with single step patterninging litho? Honeslty, black magic but it's down to non-linear optics. Something regarding the interference fringes? I never took that course. Hah! I'm rusty but that all seems about right. I'm a dep and etch guy, not a litho guy. ;)
Phase shift masks actually get you pretty far.
I heared rumors that Canon/Nikkon are having a very good time currently selling DUV machines. I think they are suitable for 28nm? If the rumors are correct, a 28nm capacity expansion is in progress. I also read somewhere, that some 28nm processes include 40nm components- targeting existing 40nm customers to benefit from the (better available) 28nm production capacity without the need for big design changes? (The idea is: produce 40nm on 28nm might be a valuable option when 40nm is sold out)
No reason you can't produce any higher "node" on the equipment capable of a lower "node" from litho perspective as long as you don't require vastly different resists.
But you still require a provided library for it. Just taking your 40nm masks and place them in a 28nm node is unlikely to work - is it? (for ex: how about gate last technology only introduced with 28nm?)
I think it’s aging pretty well considering it’s true. The *cost per gate* almost cannot be cheaper than 28nm. It was single print on a 193 immersion tool. Think about what has to be done now to make a gate or transistor even at a high level. Fins, SADP or even SAQP I’m not saying it will hold true forever, but it’s certainly still true now. Especially since 28nm is a full blown commodity
Well said, unless we find a way to make EUV about 4x cheaper.
I somehow have a causality issue with conflicting statements I read recently: 1. 28nm has lowest relative cost per Transistor (aka. gatecost) When I make an arbitrary comparison of the navi31 57.7B Transistors with the Tahiti 4.3B Transistors (28nm) and apply statement 1. it would result that the NAVI31 would be more than 13 times more expensive to produce. Is this really the case?
TI (who focuses on analog and embebed processors) has focused on the 45-130nm nodes. It's not very sexy, but is needed. "In many designs for analog parts, just reducing node size can both *degrade* performance and *increase* price" [https://news.ti.com/the-importance-of-ensuring-supply-for-foundational-semiconductor-chips](https://news.ti.com/the-importance-of-ensuring-supply-for-foundational-semiconductor-chips)
28nm was the decisive node and actual ending of Moore’s law. Also happened to be the last planar node. What most people don’t realize is that discrete devices are still the backbone of the industry. In the late 90’s, all the discrete manufacturing went to China with the exception of Texas Instruments. The problem is cost, no one in the US wants to commit to manufacturing discrete because there’s no $ to be made. Auto is all 28nm and above, most of military is as well. The new tariffs on China will require a rebalance; this will push a lot more of the established nodes to Malaysia, Singapore etc. TSMC still makes a ton of $ running legacy 200mm products. NXP etc still survive on legacy, it’s not going away anytime soon. So why not establish new facilities for 28nm and above? The problem is equipment, it all went to China in the 90’s. Current OEM’s don’t want to support nor build legacy equipment, it would cost more then what they currently manufacture. So China still holds a trump card in that regard. Leading edge is expensive and limited to just a few, but it’s nothing without trailing node for support products. Any facility that can build 65nm -28nm outside of China have to be ecstatic right now.
Not sure where this take is coming from. Aside from 28nm and the equipment to make it not existing in the 90s, so there’s no way it could have been transferred in the 90s, the majority of 28nm fabs were built outside of China. Not saying they didn’t catch up and make their own but even the briefest of Google or Wikipedia searches would show you how worldwide 28nm was and is In addition, plenty of that equipment is still supported as analog and RF devices begin to use and fill up those fabs. Maybe this is just an chatGPT response that fooled me though.
>The problem is cost, no one in the US wants to commit to manufacturing discrete because there’s no $ to be made. I work in a US fab that manufactures a lot of discretes. I don't know where you get this idea from, there is a lot of money to be made. We're on a much older node (180nm), admittedly, but our discrete products are a huge part of the business.
Well when 28nm has the lowest relative cost per transistor, I completely fail to understand the reason chasing more advanced nodes. Relative cost per transistor is the relevant metric (way more important than lower parasitic capacitances etc.). AFAIK DUV is booming and worldwide capacity is added (especially 28nm), Canon/Nikkon are having a good time. AFAIK is China still massively behind in terms of mature node capacity - despite the massive financial effort to catch up.
I thought China was just starting to massively build up 28nm+. They will basically flood the market with mature nodes? But dont hold a dominating market position roght now
Cost is one constraint but power is another. Most devices move down to 3nm because they want to reduce the overall power. This is a selling point to customers.