"The holy grail in this field is getting sufficient radiation hardness without resorting to any of the high-overhead schemes, such as shielding, process hardening or triple modular redundancy," said principal investigator John Cressler, an EE professor at the Georgia Institute of Technology. "We are closing in on that goal, using silicon germanium electronics."More info at EE Times.
Most of the advanced electronics now used in space were designed for the relatively benign atmosphere of Earth. When used in spacecraft, conventional electronics often require heavy shielding to prevent radiation damage, as well as triple redundancy to compensate for exposure to cosmic rays.
SiGe is naturally resistant to ionizing radiation, which comprises smaller particles, such as electrons and protons, that move at high speeds but do not deeply penetrate circuits. Cosmic rays, however, involve heavy ions moving at speeds so fast that no medium can stop them. When cosmic rays rip through a circuit, they affect charge distribution, causing a local error in the circuit. So Cressler's group is designing its SiGe circuitry to withstand such errors.
NASA turns to silicon germanium for radiation-immune chips
Posted on Tuesday, November 17 2009 @ 20:41 CET by Thomas De Maesschalck