When will Moore's Law no longer hold? For 40 years, semiconductor manufacturers have successfully lived up to the challenge of doubling the number of transistors they can squeeze onto a chip of silicon every 18 to 24 months. This magic trick has bequeathed the world computing devices that are constantly pulling off the astonishing feat of delivering greater power at less cost. Occasionally, someone will predict that the party is about to end, but so far, no one has been right. As a consequence, culturally speaking, we expect that the iPod Nano or iPhone that hits the stores six months from now will have twice the memory and be cheaper than what's available today. This expectation, satisfied, has become practically an inalienable right.
And so we head relentlessly on to the next "process node." Right now, the bleeding edge of semiconductor technology is considered to be the 45 nm process node -- by which it is meant that the elements on a chip are about 45 nanometers apart, (although in reality, some are closer and some are farther.) Work is well under way figuring out how to achieve the next process node, 32 nm.
But what happens after that? Electronic News offered a new twist on this age-old question last week, suggesting that while semiconductor manufacturers have a pretty good handle on how to achieve the next couple of generations, they are uncharacteristically at sea as to how to make the leap into even more nanoscopic territory.
While researchers can see their way down to the 22-nm process node -- roughly two nodes ahead of where they are developing now -- the next step is completely out of focus for most of them. Until now, the road map always was understood for at least several successive generations ... Beyond 22-nm, however, most executives say there is almost no understanding of technologies to be used or the equipment that will be needed to create it.
One quote from a semiconductor company executive jumped out at me.
"When you get down to 22-nanometers, you have 220 Angstroms. If you figure the average diameter of an atom is 5 Angstroms, that's giving you roughly 40 atomic layers. You don't have much material to work with."
Angstroms! I'm no physicist, but it seems to me that when we begin measuring distances in angstroms we are approaching some rather serious physical limits. I wouldn't be so rash as to suggest that it will be impossible to keep getting smaller, but I'll bet it will start to get pretty darn expensive. Moore's Law is not a natural law; unlike the laws of thermodynamics, it is eminently repealable.
Metaphorically speaking, the end of Moore's Law would be quite a shock. Moore's Law inspires the kind of techno-utopianism that believes, almost as an act of faith, that humanity can innovate itself out of the messes it creates by sheer cleverness. Peak oil? Don't worry about it -- once Moore's Law starts working its magic on solar power, we'll have all the energy we need. World hunger in an era of drought and devastating climate change? No problem. Moore's Law applied to biotechnology tells us that we will keep redesigning plants to deliver ever greater yields under ever more drastic conditions.
There are some truths buried in there. Our fantastically exploding knowledge about the genetic structure of life would not be possible without cheap computing power. The application of semiconductor manufacturing economies of scale to solar power will bring down costs and make solar power a competitive source of electricity. But there's also a dangerous assumption built in; that we can keep this hustle going on forever. We're like those chip execs who are confident that they can to the next level, even if they have no idea what technologies they'll have to devise to get there. Oh, we'll think of something, we always have.
But when you start measuring things in angstroms, isn't it possible that you're beginning to run out of room?