Radiation-Resistant Chips for Sturdier Satellites

Space is a tough environment for electronics. A burst of radiation from a
solar flare can damage a satellite’s delicate circuits and knock years off
its working life. Now research by a University of California, Davis,
engineering student is pointing the way to more radiation-resistant
microchips.

Anne Vandooren, a graduate student in the Department of Electrical and
Computer Engineering, studied how heat, gamma rays, X-rays and proton
irradiation affect microchips built with silicon-on-oxide (SOI) technology.
SOI chips are used for low-power applications such as cell phones, pagers
and personal organizers.

Radiation damages microchips by creating electrical charges in the
insulation between transistors, said engineering professor Jean-Pierre
Colinge, who supervised the project. His laboratory has previously developed
ways to build SOI microchips where transistors are in less contact with
insulation.

During her research, Vandooren was able to develop a general model of how
radiation affects analog circuits. Analog circuits allow digital systems to
connect to the real, analog world, Colinge said.

“If we expose circuits to a level of radiation, we know what to expect,”
said Colinge. This meant that they could design entire systems that were
more resistant to radiation damage, he said.

Vandooren carried out irradiation experiments and measurements at the
Lawrence Livermore National Laboratory and the Jet Propulsion Laboratory,
Pasadena. Other collaborators on the project were the Catholic University
of Louvain, Belgium, and the National College of Electronic and
Radioelectricity Engineering in Grenoble, France.

Vandooren’s thesis was selected as “best dissertation” at this year’s
College of Engineering commencement ceremony at UC Davis. After being
courted by research labs and tech companies, she is now working on a
related project for Motorola.