Thin, Bendable Chip May Give Cameras And Cell Phones Computing Power

Thin is always in. Runway supermodels have played that concept to extremes for years, but in the world of semiconductors, ultrathin and flexible chips are just taking their first strides toward commercial viability.

Modern semiconductors carry an ever-increasing number of transis-tors, which has led to innovations such as the multicore processor over the past couple of years. But a separate effort to create ultrathin and flexible chips may make it possible to add computing, sensing, and imaging capabilities to electronic equipment. The resulting "silicon nanomembranes" will measure 100 nanometers or less in thickness.

A team at the University of Wisconsin-Madison, led by computing engineer Zhenqiang Ma and material scientist Max Lagally, has developed a process for removing a single layer of semiconductor material from a normal chip substrate. That thin layer can be transferred onto flexible materials to create ultrathin semiconductor membranes that can fit in small devices such as cell phones and digital cameras. The film can be wrapped inside crevices and other tight areas in handheld equipment and transferred to materials such as glass or plastic.

Thin-film semiconductors are unlikely to find their way onto PC or server processors in the near future, but they are expected to gain traction in semiconductor chips used in displays, RFID tags, and low-power digital switches.

On The Flip Side

In addition to having a silicon layer on the thin film, the devices can be flipped to make the reverse side available for a layer of components, or multiple layers of film can be stacked to create three-dimensional devices.

Several of the thin-film devices could be applied as a sheet to imaging applications, creating an array of thin processing elements to be used in high-resolution displays and graphics equipment. "It can be like a piece of Saran Wrap," Lagally says. "You can straighten it out perfectly well, and rumpling doesn't cause any defects. It's really totally amazing."

The ongoing work at the University of Wisconsin is supported by grants from the National Science Foundation Materials Research Science and Engineering Center, the Department of Energy, and the Air Force Office of Scientific Research.

The university will patent much of the technology it's developing, but Lagally says technology companies are likely to use the school's research in commercial products that could hit the market within a couple of years.