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Comment on Transistor Options Beyond 3nm (2018)

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At each node, process cost and complexity are skyrocketing, so now the cadence for a fully scaled node has extended from 18 months to 2.5 years or longer. In addition, fewer foundry customers can afford to move to advanced nodes.

So of course let's not even mention any technology beyond silicon photolithography.

They mention a 1.5nm process node, which is 7.5 silicon atoms wide. So: A) why aren't we talking about 1.4 or 1.6 nm instead? And B) at what point will the industry acknowledge the need for atomically precise manufacturing?

The process name doesn’t have anything to do with the physical dimensions of the transistor. It’s a marketing term, a lower number implying a newer node.

Besides, using one metric to measure a 3D object wouldn’t make too much sense, at least in the case of a FinFET transistor. A more useful metric would be transistor density.

The process name doesn’t have anything to do with the physical dimensions of the transistor. It’s a marketing term, a lower number implying a newer node.

It seems I'm definitely in grumpy old man territory these days when things like the process node name which used to actually mean something specific, don't anymore.

It still means something specific. It's an extrapolation of the transistor density. The design rules on state of the art processes are too complex to summarize with a simple single number like in days past, so this is a reasonable way to describe things. The argument that they're purely meaningless marketing numbers is just tired empty smugness. When we talk about TSMC 7nm everyone knows what that means and that it is indeed a significant advance over the prior nodes. The numbers capture the advantage in rough terms, as best you can.

Yeah, I’m with you having worked in a fab for a short time.

But... it assumed all other things related to structure and configuration etc remained the same. That hasn’t been true for a while and so now it’s “10nm equivalent” shortened to 10n. Can’t remember when that started to change... maybe at 280?

I dont blame them. Some company made the first claim, others try to resist. Then customers demand a new node for their marketing.... and that is how we end up with these numbers.

What is the magic technique?

Selective growth and patterning already have precision in the sub angstrom range, over mms of distance. This is what 'TMU' is, when you read an ASML or Lam paper on the topic. Current target is sub nm, for total variation cross die per layer.

I strongly recommend a read of the Tennant's law series onnlithoguru, or Tim Brunner's paper on why optical lithography wins forever.in short, optical is better (including EUV).

There are whole conferences dedicated to atomically precise manufactue, and hundreds of not thousands of people working in the field.

And B) at what point will the industry acknowledge the need for atomically precise manufacturing?

I think we are already there, some of the layers already have thicknesses of only five or so atoms.

"C"... Just for a moment i was reminded, there was some stuff called graphene and buckyballs...[1] -but that maybe another topic... ^^

[1] >//en.m.wikipedia.org/wiki/Fullerene

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