Gallium Arsenide

PC MAGAZINE: On the design end you know there's a lot of people that talk about a lot of very different kinds of ways of making semiconductors, whether it be gallium arsenide or multi-state logic, or all of those things. Which, if any, of those high-end stuff do you think are really important things?

GORDON MOORE: Well, somebody once said, "Gallium arsenide is the material of the future and always will be..." I spent a lot of money on gallium arsenide in the '60s and got convinced it was a fairly intractable material. It's neat for the front-end of cellular phones when you want a little bit of stuff that's high-performance, but it's not going to compete in the mainstream. You know we now do everything on 8-inch wafers--nobody's seen an 8-inch wafer of gallium arsenide. We'll be at 12-inch wafers probably by the end of the century. People can't grow crystals that big in any of these other materials! So I think the mainstream is likely to be silicon-based forever. But I don't see that as the critical thing any more, you know, I view the technology as a general-purpose method of making complex structures and materials layer by layer. And it doesn't make too much difference what those materials are--and they can even be used for a lot of things other than electronics. You've got all of these micromechanical machines that people are demonstrating now that are really interesting. They use the same technology, building gears and wheels and motors and sensors. You've got people building little chemical laboratories: I know a company that makes a blood analysis chip that in 90 seconds, you put one drop of blood on the chip, plug it into this machine, and in 90 seconds it'll give you an analysis of six of the major constituents of your blood, with the precision you can get sending it to a laboratory. And it has all the reagents in there and everything, all the sensors. A lot of things are being made out of this technology now, and to me it's just a general-purpose technology. I call it as fundamental to the information age as metalworking was to the Industrial Revolution. So I don't care, if gallium arsenide sapphire turns out to be the material that we ought to make our fast computers out of, except for the problems of growing big sapphire and the like -- they give you some trouble -- the basic technology will be kind of 90 percent the same. You've got to change the 10 percent that relates to the particular material, but the rest of it -- building up six or seven layers of interconnections, with all the insulators and barrier metals and everything you need--that's getting to be a lot more of the process than the handling of the silicon itself now.


PC MAGAZINE: Other people are talking about different ideas, again, built based on the same fundamental technology--things like multi-state logic, fuzzy logic. . . things like that neural networks. Is any of this stuff of interest?

GORDON MOORE: You know fuzzy logic evidently has proved to be useful in some of the control systems. I don't understand much about that. Multi-state stuff, with the possible exception of memory, usually turns out to cost so much in time that it's not worth it. People are solving a non-problem in my view when they're looking at [it]. Neural nets are a different deal. Neural networks are a completely different way of doing computing, and do some things very well--like pattern recognition. And if you'd asked me five years ago, well, I would've thought that they would've carved out a nice niche for themselves. The funny thing is, all the neural network stuff that's being used that I know of is simulating neural networks on digital computers. The software simulation turns out to be the way that they're being made instead of getting hardware out there. There's still companies, I guess Synaptics here locally--is pursuing, I think they're still pursuing hardware versions of neural nets.

PC MAGAZINE: I'll just toss out some things that people talk about, they talk about, there's a lot of talk about optoelectric chips, using light more, holographic memory.

GORDON MOORE: I am not a real believer in optoelectronic chips to do computing.

PC MAGAZINE: Holographic memory?

GORDON MOORE: Holography memory? I'm not close enough to that. The densities people talk about being able to achieve are phenomenal: a lot of information storage. It's capable presumably of giving one of these real qualitative leaps in the amount of stuff that's available. Something may come of that. I'm not close enough. On the other hand, the ability of the magnetic disk people to continue to increase the density is flabbergasting--that has moved at least as fast as the semiconductor complexity. You can get a 2.5-gig drive for 200-and-some bucks now down at Fry's! [the Bay Area electronics superstore chain] It's absurd!

PC MAGAZINE: What about some of the quantum computing ideas?

GORDON MOORE: The quantum computing, that's a hot new one. Again, you know--this is getting further and further away from my area of expertise. I think quantum computing is a very interesting concept to understand quantum mechanics. I think it has no practical application whatsoever.


PC MAGAZINE: Okay. . . let's go back more to current things. A few years ago you guys were talking about the Micro 2000 project. You know, I don't hear about that any more--what happened?

GORDON MOORE: We were a little behind in complexity, and are probably going to fall a little behind, mainly for economic reasons. You've got to make bigger chips if you want to get to 50 million transistors; we may only be someplace between 20 and 50 instead. We were right on with respect to the level of technology, minimum feature size--but that's a step function, and we just happened to cross it exactly at the right step. But it looks like that one we'll follow pretty well. The thing that was amazing is that we were significantly ahead in clock frequency and in performance. The people that had done the Micro 2000 were design people, so they put all the pressure on the technologists; they didn't leave anything to themselves, and it turns out the designs have been much more effective than they imagined at the time.

PC MAGAZINE: You talked about the "2011" chip. . .

GORDON MOORE: Oh, yeah, that was Andy [Grove]. He gave a view of that at Comdex and I wouldn't want to take credit for any of that. I think somebody got carried away with his semi-log paper. They were very aggressive extrapolations.

PC MAGAZINE: So you think a 10-gigahertz chip with a billion transistors on a .07-micron process is. . .

GORDON MOORE: By 2011, that's asking for everything to fall in line perfectly. A 10-gigahertz chip of that complexity, to keep the power in anything reasonable and tractable is really tough. The power thing really becomes a problem, and I consider that one of our biggest challenges, particularly for laptop systems, for cheap desktop systems. The power wants to go up to hundreds of watts as you go in this direction, probably thousands of watts if we go that far, and there aren't simple systems for taking that kind of power out. I start to understand why the mainframe people used to circulate Freon and water-cooled and the like. You really are pushing the power as hard as you can and I think that's going to limit these combinations. The .07 is right at where we talked about lithography a little earlier, that's down in the range where we've got to work hard to get there.