Gregg Zank, CTO, Dow Corning

Gregg Zank (Source: Dow Corning)

Gregg Zank is vice president, CTO and executive director of science and technology at Dow Corning (Midland, Mich.), where previously, as director of New Ventures R&D, he developed the R&D organizational strategy for New Ventures — which he still directs — including an internal new business and technology incubator. Zank completed the Kellogg School of Management Executive Development Program at Northwestern University, has a Ph.D. in inorganic chemistry from the University of Illinois at Urbana, and a B.A. in chemistry from the University of Wisconsin at Superior. Dow Corning is a global company focused on silicon-based technology and innovation. It is owned equally by The Dow Chemical Co. and Corning Inc.

SI: Where is R&D going at Dow Corning?

Zank: We're seeing excitement in the light management (LED and optoelectronics) materials we recently announced, activities around displays, materials for thermal and electrical conductivity — those are the major areas — and we're pulling in a number of things to make those materials thrusts a reality for us.

SI: What does your technology roadmap look like for the next three years?

Zank: It covers the areas already mentioned, plus things a little removed from the semiconductor sector, such as solar renewable energy. We continue to focus on things like front-end CMOS processing, interlayer dielectrics, and our materials for development and use in the lithography area. We're developing materials for the 45 nm node and beyond, as well as for packaging, which takes us into larger devices and displays.

SI: With packaging becoming a part of the circuit, how do you see things developing in this area?

Zank: It's an interesting area, because it isn't just packaging. Many traditional segments are beginning to blur. You can view this from the perspective of optics and electronics — what's going to be done on the circuit and what's going to be done to connect different devices together. The same is true for packaging: You must be able to integrate the packaging design and packaging materials requirements to the increasingly specific chip-by-chip product, not just something that is put in later downstream.

SI: How do you define your roadmap and establish your R&D guidelines?

Zank: Nothing replaces the customer's voice. One of the things we do well, especially in the electronics area, is having multiple touch points with customers. One is always working to streamline processes and produce the new materials that'll be needed. However, one needs an insight into the customer's R&D and longer-range activities as well. This is helpful because it shows us whether or not we're moving in the right technology direction and, at the same time, it enables us to begin early work on what will be required, such as new molecules for low-k dielectrics or other future deposition areas. It also permits us to solve any problems that might exist with our current products and materials. This relationship forms the touchstone of our research. It helps us to focus on areas such as thermal conductivity, packaging and the rest.

SI: You do considerable work on wafer substrates and compound semiconductor solutions such as silicon carbide. Can you update us on your efforts in this area?

Zank: We're doing this for a wide range of users, and are convinced that there is a need for a reliable source of "known good substrates." We're doing extensive R&D in the compound semiconductor area — our manufacturing processes to grow the boules, our wafering and polishing. In these manufacturing steps we believe we are world-class from the standpoint that, once the boule is grown (and there is considerable art and science that must go into it), we like to think we're the ones to come to when wafering and polishing are needed. As we grow and put this supply chain in place, we're positioning ourselves to be a key player in the delivery of these known good substrates to the market.

SI: How do you see the situation of the engineered substrate — SOI and others? It seems as if device makers will try anything before resorting to it.

Zank: We're comfortable on both sides of that street, because aside from the highly engineered compound semiconductor perspective, we're the world's largest manufacturer of polycrystalline silicon. SiC and some of the other substrates were for us a natural extension of our presence in silicones. The longer device makers lack access to reliable supplies of these known good substrates, the more we are going to see creative engineering to work around these other substrates and engineer more using things like strained silicon.

SI: New materials are being introduced at unheard of rates. How are you meeting this challenge?

Zank: "Challenge" is indeed the word. Just as is the case with substrates, materials is an area in which the prizes go to those best able to solve complex problems. If the problems were simple, there'd be more players in the game. This is where a carefully established R&D plan pays off. Silicone-based and silicone hybrid organic materials are the solutions to many of these problems. Although the entire industry has always been based on the silicon atom, I still find it remarkable that there remains much to be learned about this material, which can then be applied to find solutions for special needs.

SI: When do you see silicon running out of steam?

Zank: (Smiling) As someone in a silicon company, I have to say "never." The question is difficult to answer, because we have — as in the case of electronics and optics — a blurring of technologies. From our perspective, a shift from silicon to silica is possible, and wouldn't be a bad thing. Engineers are very clever and constantly devising workarounds to avoid silicon's demise. Will it ever happen? Probably, but I believe that it will be many generations before it happens.

SI: Are you doing much in the nanotechnology area?

Zank: Yes. That being said, I'm proud that we, as a company, have resisted the urge to re-name everything "nanowhatever." Strictly speaking, the industry has been doing nanotechnology for quite some time. I am on the President's Nanotechnology Advisory Council, and like most other companies, Dow Corning is very interested in the subject. One of the areas that attract us is nanosilicon materials. Although they aren't traditional semiconductor materials, we think hybrids may be the segue that leads us to printable semiconductors or quasi-organic materials, where you combine nanofeatures around silicon and polymeric materials. This may be the transition point that awaits us in the future.

SI: So you expect us to enter a hybrid world?

Zank: It would be a natural transition. If you consider electronics and optics, there is that optoelectronics transition. There will be opportunities for printable organic electronics, but also other chances in hybrid schemes.

SI: Some are beginning to talk about 450 mm wafers. How do you see the lay of the land?

Zank: It will happen, but when is not easy to predict. One of the hurdles is that our industry has a tremendous infrastructure, and when you begin looking at such an alteration, you must also consider how much of that infrastructure can still be used — changing tools and equipment to handle 450 mm wafers is truly a daunting prospect both from an engineering and capital standpoint. Then also, a 450 mm wafer would be extremely thin and fragile, making it very difficult to handle. It certainly is the way to go, but some very tough technical challenges in tools and processing are going to have to be overcome first. The investment all of this will require will not be trivial.

SI: What are the leading obstacles that device makers face over the next three years?

Zank: As everything speeds up and shrinks, thermal control emerges as a leading hurdle. I believe the solution that will emerge will be a combination of engineering and materials. Some production steps will have to change, or we'll have to start integrating more optics. We're working with some industrial partners and academia to solve some of these problems. We are involved with Cambridge University and their Center for Advanced Photonics and Electronics (CAPE) to develop materials and procedures to meet these difficulties.