For decades there has been a new CMOS technology node approximately every two years. Until recently, thanks to scaling, the key feature of every new technology node has been a 100% integration capacity and 40% performance improvement… free-of-charge. The International Technology Roadmap for Semiconductors (ITRS) has been architected in such a way that this improvement became a self-fulfilling prophecy of the roadmap itself. Everything else has been bent in the attempt to make scaling happen… forever. That has changed as we approach the near end of Moore’s Law - 3.5 Nano Meter design with new Extreme UV machines. We will look at how the landscape has changed and where we can go from here.
For eons snails have built the cells of their shell according to the Fibonacci’s numbers: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, etc. – where each cell has a volume that is the sum of the volume of the previous two cells. Snails understand, however, that at a certain point in time growth must stop to prevent the collapse of the shell by making it too big and therefore fragile. When this point is reached, snails do stop adding larger cells, and start improving the robustness of the shell.
Back to us: technology-wise, scaling has rapidly exhausted the resources of CMOS technology, which, by now, struggles to deliver any further improvement. Economy-wise, Dr. Gordon Moore once observed:
“what we end up doing is really selling real estate. We've sold area on the silicon wafer for about a billion dollars an acre, that order of magnitude, as long as I've been in the industry”
In order to stay afloat, the semiconductor industry would need to double the number of units it sells, from one technology node to the next. Not only is this clearly impossible, but it puts the semiconductor suppliers on a collision course with their customers, who are now looking for half the silicon area from one technology node to the next. Atoms don’t scale, and markets are finite.
A number of fundamental challenges have emerged, both technical and financial, which force a thorough rethinking of how scaling has been done, and whether scaling continues to be the most appropriate solution to provide the world with the silicon content that it needs.
Like Al Gore’s premise on energy consumption and global warming, there is an inconvenient truth to be acknowledged in our industry: scaling is like fossil fuels – the cheapest and easiest way to go. Unfortunately, also like fossil fuels, it is not sustainable indefinitely. And it becomes more costly and inefficient every day. New avenues, which are available today, are worth exploring and must be undertaken. That is, unless snails are more intelligent than us…
In this talk, Dr. Williams will describe the problems with scaling and a number of possible solutions, including the latest alternative paths and their relative merits.