
2nm
Wish that was an accurate way to measure chip density, but it's as defined as a politicians opinion.
Samsung is the latest chipmaker to benefit from CHIPS and Science Act funds, with the US Commerce Department today announcing the Korean megacorporation is getting $6.4 billion in funding to expand its Texas operations. In a statement published today by the Commerce Department, which is managing the billions of dollars being …
The M0 Metalization Layer pitch is a good indicator. It currently sits at about 30nm~36nm This number is lower in the current nodes, but will get slightly higher in the nodes with backside power delivery, before getting back down if/when we go to full cobalt (sans cooper) interconnects.
But advances like High K gates, FinFets, Gate All Around and others kept moore's law going for a while longer. This doubling of performance whas detonted by a nm designation, even if, below about the 28nm, the actual number is more a marketing moniker than a real dimension on the slilicon. Also of note is that, between the 12nm and the 7nm nodes, the SRAM transistors (used, among other things, for cache) stoped shrinking. Nowadays, most of the silicon area of our µProcessors and SoCs is cache.
TL;DR: Ask for the M0 pitch to know the true size of features in the silicon beyond the marketing nm number. But the marketing nm number still has value.
M0 has only been decreasing because there wasn't room for bigger wires in all the congestion. As you say M0 is increasing with backside power and will probably not decrease all that much after that because the congestion issue is greatly mitigated between backside power and nano TSVs. I've seen suggestions that transistors would have to get 10x denser before M0 had to drop much below 30nm, and even then the downside to making M0 too small would make them work really hard to find ways to avoid that.
Transistor density is problematic because of the differences in the way it is measured, but it is much better than M0 for tracking progress of miniaturization of transistors.