Ken Gilleo, CEO, ET Trends

Ken Gilleo (Source: ET Trends)

Ken Gilleo is the founder and CEO of ET-Trends LLC (Warwick, R.I.), a consulting and IP firm focused on emerging technologies. Gilleo has more than 35 years experience with electronic packaging companies, including 3M, Allied Signal, Cookson Electronics, Poly Flex Circuits and Tessera Technologies. He has extensive experience in printed circuits and polymer thick-film electronics. Gilleo is an inventor who holds more than 33 U.S. patents, and his products have won three R&D 100 Awards. He has authored over 500 papers, presentations and workshops. More recently, he has become an expert witness for patent litigation. Gilleo holds a Ph.D. in chemistry from the University of Connecticut.

SI: You have described yourself as a futurist. Arthur C. Clarke once remarked, 'The future isn't what it used to be.' How do you go about doing your predictions?

Gilleo: You cannot just concentrate on the industry you track; you must look beyond. People now talk about stacking packages and where it is leading. Back in 2001, I wrote an article entitled, 'No Place to Go But Up.' It didn't take too much imagination then to realize that this was how we would achieve greater density when silicon became footprint-restricted. What was interesting was that I discussed whether one would need to continue with vertical metal connections, which are difficult to do whether on printed circuits or some other configuration. The idea struck me that one could perhaps use light instead; however, many things had to happen first. Now, with Intel and IBM having achieved many breakthroughs in the silicon photonics area, I would predict that within 10 years we won't be worrying about lasers drilling vias through the stack — we're going to use light, probably infrared, since it goes right through the silicon, directed, perhaps, by integrated prisms.

SI: That's a lot of connections you're making.

Gilleo: True, but when you let you imagination go a bit, 'light-linking' begins making sense.

SI: In pursuit of Moore's Law, device features will continue shrinking and densities will continue increasing. How do you see this?

Gilleo: As a chemist, I look at it from the molecular perspective, and not necessarily from a product point of view. Molecules are very democratic — they don't care which industry they are in; for instance, the circuit board industry has been making vertical connections for years. Semiconductor engineers are only now thinking about how to do that. There's no harm in taking the chemistry and arranging the molecules in the way they did with the early multi-layer printed circuits and applying that to semiconductors. Every industry must keep abreast of what others are doing; the laws of science couldn't care less where they operate. It is a very valuable exercise to move ideas around from various sources. This is something that the semiconductor industry hasn't engaged in enough.

SI: Why would that be?

Gilleo: Because it tends to be elitist. A large part of it is composed of very intelligent, highly educated people, so when you suggest that they might apply some ideas from the printed circuit industry, they look at you like you're out of touch.

SI: When you speak about pushing molecules around, you enter the nanotech regime. How do you view the semiconductor nanotech effort?

Gilleo: The idea of nanotechnology is fine as far as it goes. But it has been so overhyped by many academics (who seem to get most of the money) that there is general confusion about what it really is. Although semiconductors today are at the nanoscale, to me that isn't nanotechnology. Once you begin doing things with carbon nanotubes and have completely difference phenomena taking place — quantum effects, etc. — you'll be there.

SI: Is there anything that the semiconductor industry isn't doing in nano?

Gilleo: Considerable resources have and are being allocated for it, and researchers are doing breakthrough work. However, sometimes more honesty would be a good thing. Much of what's being done is really Chemistry 101 under a nanotech umbrella. Chemists have worked in the nanoworld for generations, so we understand what nano is and isn't. However, I'd like to see a good effort using a carbon nanotube transistor or some other system where we don't waste money on replowing the field and really begin solving the big problem, which isn't the transistor, but the interconnect.

SI: Is the problem that a great portion of the effort goes not so much into developing new ways of doing things, but in trying to extend CMOS' life?

Gilleo: Attempting to push things to the limit is sensible. I remember back in the old disk-drive industry, when it was thought that some sort of replacement would be needed for future storage densities. Well, the densities were attained and disk drives are still here; and the same is true of silicon. Every time we think there's a roadblock, someone finds a new path, like immersion lithography, or new materials.

SI: But fundamental limits will be reached.

Gilleo: Yes, and that's probably 10 or 15 years away. It's also apparent that by going to something other than silicon we can get a capabilities' bump that's going to be several orders of magnitude greater than what we're able to do today. However, I'd rather call that something 'molecular electronics' instead of nanotechnology. As a chemist, I've worked in the 'sub-nano' field for decades, so why be limited by 'nano?'

SI: A rose by any other name?

Gilleo: (Smiling) True, but a nanotube is just an organic molecule, one of the many manifestations of carbon. It'll have to do something better than silicon. I like to refer to this as 'non-silicon electronics,' because it includes anything new that comes along. We must think in terms of using molecules, and the most sophisticated molecules we're capable of making are organic. The big breakthrough will come when we finally learn how to do true organic molecular electronics, whether it is nanotech, plain chemistry or a hybrid. Our brain doesn't need silicon.

SI: But there have been breakthroughs with nanotubes.

Gilleo: Certainly. The IBM group, academia and other researchers have proven that the carbon nanotube makes a good semiconductor that can become a transistor. However, we don't yet know whether this will be the final version or if there is some better structure. Meanwhile, we're learning how to better manipulate these carbon devices. The question is how to arrange and pack them as we do now with transistors. Will it be lithography? Will it be some sort of force that lines up the nanotubes? The problem is completely different from anything we have previously encountered, and will require a unique solution — probably at the molecular, or even atomic, level.

SI: Nanotech is promising, but it also brings us closer to hitting fundamental barriers, coping with quantum effects.

Gilleo: That is true. As we learn more, we'll discover that some of those fundamental barriers aren't as significant as those for silicon. For instance, with nanotubes, heat is not expected to be as big a problem as we progress to ever-higher densities. Also, in traditional packaging, a big problem is corrosion. Because you have metals in the interconnect, many things can go wrong. One of the purposes of packaging is preventing chemistry from taking place. Carbon nanotubes and the other structures being considered for molecular electronics do not appear to have the same moisture-sensitivity issues. In fact, they tend to be non-moisture-absorbing — carbon is fairly inert unless greatly heated. We may end up with fewer problems than with silicon, certainly in the packaging area.

SI: Is molecular electronics the only major trend you see?

Gilleo: It's certainly a major one. However, I see considerable efforts being exerted in Silicon Valley and other semiconductor venues toward solving silicon's problems. Some of the things that we think will happen at the 32 nm node or below may have workarounds that avoid them. Twenty years from now, we may still be doing very well using silicon.

SI: Still, there are limits.

Gilleo: True. However, using the old disk drive example again, we thought that optical storage would eliminate everything magnetic, and that we were hitting the limits of magnetic storage technology. Suddenly, IBM came up with a fundamental breakthrough based on magneto-resistive phenomenon and, later, Seagate began working with vertical recording. This industry has managed to increase storage densities about two orders of magnitude from what we once thought were absolute limits. To some extent, I believe the same will happen with silicon. We don't see 'disruptive' technology or science coming until it hits us.

SI: Going from the small to the large, how do you view the 450 mm wafer question?

Gilleo: I don't believe that it's going to happen, or needs to happen any time soon. Things could reach the point where only one company (or country) can afford a new fab. Look at those doing MEMS work, they're quite satisfied with 4- and 6-in. wafers and don't need to go to larger sizes for awhile; meanwhile, they can use older fabs. If they to go to a larger size, some would be less cost-efficient — their economic model could collapse. When we make one of these dimensional jumps, it affects everything, and now costs are at a point where this sort of expansion is getting extremely difficult.

SI: Will things then go from larger to smaller?

Gilleo: No, but I do see smaller wafer sizes being viable. Microbreweries and steel mills do quite well by right sizing, for example. Those working with gallium nitride do not require 300 mm wafers, and there are many interesting devices that can be efficiently produced at smaller sizes. Silicon can remain where it is and do quite well. And we don't know what size molecular electronics will need. Wafers themselves could be-come obsolete.

SI: Do you see offshoring as having had a negative impact?

Gilleo: It has changed R&D. There is now a disconnect between designer and manufacturer. In some cases, we opted for offshoring R&D. Although there are good people overseas, they think and do things differently and often lack experience. China is an example. If they do the R&D, whom do they fall back on? Whom do they ask for help? Do they have anyone who has been working in the industry for 20 years? The answer is no — no homegrown senior techs. Eventually it'll change, but right now there is a considerable knowledge and training deficit. This is inefficient, and leads to reinventing the wheel. Plus, their society isn't as open as ours is, and not as accustomed to innovation. In the United States, you have old guys like me, who you can ask about what was going on 20 years ago. Old is not necessarily 'old tech.' The printed circuit, CRT and wireless are all over a century old.

SI: Any other concerns?

Gilleo: Only that things are happening at an increasingly faster rate. Sometimes this makes developments seem chaotic, and that may not be true. Developments aren't going to slow down, and he who blinks may be lost. We really must keep up and stay sharp.