Home : Volume 26 : Fall 1999 :
Looking in on COLLEGE OF ENGINEERING alumni

Jeffrey Miller, MS '97 (Nuclear Engineering & Engineering Physics) Process Engineer, BALL Semiconductor Inc. (22K JPG)

Jeffrey Miller had been working as a process engineer in the world of flat semiconductors when he started to grow restless. He enjoyed his work in the manufacture of 16M/64Mbit DRAM but wanted to know what else was out there. In looking for a new opportunity, he came across Akira Ishikawa, a former president of Texas Instruments Japan Ltd., who was promoting a radical idea. The world of semiconductors need not be flat, Ishikawa said. It could be round.

At the time, Miller's employer was being acquired by another company. He joined Ishikawa's company, BALL Semiconductor. BALL is developing manufacturing techniques to produce integrated circuits, sensors and other microelectronic devices on silicon spheres as opposed to flat wafers. The company believes its technology will reduce the cost of chip manufacturing by up to 90 percent by making products in components in a one-step enclosed system of small hermetically sealed tubes and pipes rather than in large, expensive clean rooms. As conventional wafers continue to grow in price and size and as the size of the devices crammed onto them shrinks, BALL Semiconductor is betting its streamlined manufacturing process will change the industry.

Three-dimensional microscope picture of a patterned oxide ball. (11K JPG)

"It is unique," Miller says. "We are the only people in the world that are trying to do this. I think we've come a long way. Initially people thought the whole idea was preposterous...that there was no way that it could be done. People thought that we couldn't even make an integrated circuit on a sphere, but we showed them. We did it."

In April, BALL Semiconductor announced it had made history by building the world's first spherical semiconductor, culminating 18 months of intense research and development.

A bumped ball on a conventional integrated circuit. (13K JPG)

Using a combination of proprietary and traditional processes, BALL Semiconductor developed five-micron NMOS inverter circuits on a one-millimeter spherical surface. BALL Semiconductor chose to build an NMOS semiconductor as its first spherical device because it is less complicated, yet still includes all the fundamental technologies needed to build most types of spherical semiconductors. It's not just the semiconductor that looks different. Miller says a maker of flat ICs wouldn't even recognize the fabrication facilities. With winding pipes and tubes filled with one-millimeter-diameter silicon balls rolling through doping, etching and cleaning steps, the facilities look more like a chemical processing plant.

Miller came to UW-Madison in 1994 after earning his bachelor's degree in Oklahoma. He worked toward his master's in the Department of Engineering Physics (then Nuclear Engineering & Engineering Physics) studying experimental plasma physics under Professor Noah Hershkowitz. Upon graduation in 1997, he joined Twinstar.

At BALL, Miller serves as a process engineer on a team working to perfect chemical vapor deposition techniques that can be used in mass producing a variety of products on silicon spheres. The company had planned to set up a spherical semiconductor pilot line sometime in 2000 but Miller says that timeline has been pushed back. Instead of going for a "killer application" in the beginning, BALL Semiconductor will roll out other devices in order to generate revenue, including ball-based accelerometer sensors, tiny gyroscopes and radio-frequency identification devices.

One major area of application is medicine. For example, a tiny BALL sensor for recording flow and pressure can be used in stents and endographs, and the data can be wirelessly reported to a physician. Miller says BALL has filed more than 110 patents and is accelerating research and development by working with equipment manufacturers and university research labs.

Miller admits he was apprehensive at first about joining a small start-up company running on a radical idea, but with risk he says, comes the potential for great reward. He also enjoys the hands-on environment and the team atmosphere that includes everyone from a process engineer to the CEO.

"I do process development but also help conceive, fabricate and build," Miller says. "I'm involved in everything from start to finish. It's the hardest and most challenging thing I have ever done."