Semiconductor work may spur new electronics advances
A new research project in the University of Wisconsin-Madison's College of Engineering to integrate semiconductor materials may lead to new applications in sensing, computing and wireless communication.
The three-year, $1.8 million project, directed by engineering professors Thomas Kuech and Max Lagally, will investigate ways to integrate various compound semiconductor devices-multi-material devices that send, process and receive information-with silicon.
While semiconductor devices made from materials such as gallium arsenide are optically sensitive and operate faster, silicon's strength is computational power. "We hope to demonstrate that by combining the features of gallium arsenide with the features of silicon, we can get an advance over either material," says Lagally, a professor of materials science and engineering. "We call that increasing the functionality of silicon."
Funded by the Defense Advanced Research Projects Agency (DARPA), the researchers will collaborate with electrical engineers from Georgia Technological Institute, who will grow and synthesize the compound semiconductors. They will also work with an expert on structural analysis from State University of New York-Albany. Lagally will examine the project's fundamental science issues, while Kuech, a chemical engineering professor, studies the interfacial chemistry associated with bonding compound semiconductors and silicon.
The project focuses on wireless communication-the cellular telephone-as a way of starting to investigate processes on an intimate microlevel, says Kuech. The results could have an immediate impact in defense agencies where battlefield communication increasingly relies on wireless technologies. But the research also could translate to computers that quickly send mountains of data using optics instead of cables, or chemical and biological sensors in which one component integrates the optical emitters, detectors, micropumps and processors.
"Materials integration is a huge area right now," says Kuech. "What people have done is tried to do it perhaps on a much smaller scale or just tried to put a single device somewhere, and have developed a lot of processes associated with that." He says one of the group's goals, which researchers have yet to accomplish, is to integrate materials on the system level.
Combining different materials with a variety of properties and structures is the real challenge, says Lagally. "The idea of integration is to say, 'Is there some way we can intimately put these materials together so that it almost looks like one material,'" he says.
And through this seamless transition between materials, even the bonds will be functional, enabling researchers to use the entire device, says Kuech. "Functionalizing the interfacial layers is something people haven't done before in this context," he says.