It looks like you're new here. If you want to get involved, click one of these buttons!
A few years ago, I said something to the effect that if you want to know whether Moore's Law will survive much longer, check back around the end of 2013. Everyone in the industry seemed to agree that the path to 22 nm chips was open, but beyond that was in doubt.
The end of 2013 was kind of an arbitrary marker, but had Intel kept pace with their stated goals, they would have launched a chip on 16 nm by then. They haven't, and for that matter, probably haven't even started production of a chip on a new process node past 22 nm. And the problems are hardly limited to Intel. Intel launched CPUs at 22 nm in early 2012. No one else has gotten that far, even today, with the rest of the industry stuck at 28 nm. Indeed, AMD's high end CPUs just got to 28 nm last month. Moore's Law is, at the very least, experiencing a serious bump in the road.
And yet there is a perfectly good explanation for this that is completely consistent with Moore's Law still being alive and well. To go much further, the industry widely believes that they'll need FinFETs or something much like them. Intel's 22 nm process node uses Tri-Gate, which certainly qualifies as "something much like FinFETs", and the rest of the industry is working on FinFETs.
Additionally, for reasons of physics, a given wavelength of light has a minimum area that it has to hit. Having to take multiple passes to carve transistors in silicon gets expensive, and the industry is pushing toward the limits of what the excimer lasers that they've used for decades can do. The industry is relying on EUV lasers with wavelengths more than an order of magnitude shorter than currently used by foundries to replace them soon, but if EUV doesn't come through, we could be stuck for a while.
In one sense, these are the sort of challenges that foundries have faced for decades. It wasn't that long ago that they needed high-k metal gate, or silicon on insulator, or copper interconnects to advance further. Solve the latest batch of challenges just like they've solved all of the previous ones and Moore's Law continues apace after today's mere hiccup.
Foundries seem to be optimistic that they can do exactly that, too. In going from 22 nm to 14 nm in a single jump, Intel is trying for the biggest percentage jump in process node sizes that they've attempted in decades. Global Foundries doesn't want to talk much about their upcoming 20 nm process node, but wants to talk a lot more about 14 nm. They offer six different process nodes at 28 nm, but will offer only one at 20 nm, then back to many options at 14 nm. Similarly, TSMC is just starting production of 20 nm parts, but is much more excited about the 16 nm process node that they hope to replace it with shortly.
But in another sense, something is very different this time: cost. I briefly alluded to it above. It simply costs a lot more to bring up each new process node at a smaller geometry than the previous, larger one did. Exponentially more, in fact. It used to be that everyone and their neighbor's dog had their own fabs, at least as large computer chip companies went. But a company with a few billion in annual revenue can't afford to spend more than that in an average year just bringing up the next new process node. That's what drove AMD to sell off their fabs a few years ago, for example. Today, Intel is the only company in the world with enough volume in their own chips to justify having their own fabs--and even Intel is starting to fab chips for other companies.
Even if there were no problems of quantum mechanics and matter were infinitely divisible, the cost of new process nodes would eventually bring Moore's Law to a crawl if not a complete halt. Exponentially increasing costs cannot go on forever, and therefore will not. A number of foundries seem to have basically given up on being anywhere near the cutting edge. Intel still is, and TSMC and perhaps Samsung. Global Foundries is trying to be, though not necessarily succeeding amid chronic delays. And then?
This problem isn't confined to logic circuits, either. There used to be many manufacturers of DRAM chips. We are now down to three significant ones: Samsung, Hynix, and Micron.
It's still likely that Intel launches 14 nm Broadwell chips this year, and that TSMC's 20 nm process node will come along quickly enough for AMD to get 20 nm cards out this year. TSMC might well get 16 nm chips out the year after, with not just AMD and Nvidia GPUs, but a whole host of ARM chips and perhaps AMD CPUs, too. If that happens, Moore's Law will perhaps have slowed a bit, but will still be alive and well in all but its most rigid formulations.
But that's a big if. We know that Moore's Law is going to fail eventually. Nothing can grow exponentially forever, and for modern chips to have about a million times as many transistors as the cutting edge chips did when Moore formulated his famous law is astounding in retrospect. That's literally a million times as many transistors, not just some figurative "a lot more".
But that's also the sort of technology jump that is unprecedented in recorded human history, so there aren't any historical examples to compare it to and guess how it might end. I'd bet on exponential growth giving way to something less than exponential but still growth. But it will certainly be interesting to watch.