Simulation of Cosmic-Ray Induced Soft Errors and Latchup in Integrated-Circuit Computer Memories

Soft errors have been induced in solid-state static RAM's by iron nuclei from the Lawrence Berkeley Laboratory (LBL) Bevalac, in experiments designed to prove the ability of iron-roup cosmic rays to generate such errors. Subsequently, various de-lidded device types were tested in beams of argon and krypton ions from the LBL 88-inch Cyclotron, at energies near 2 MeV/nucleon. The latter tests showed that some devices are essentially immune to bit error while others are quite susceptible. Good agreement was obtained with model predictions in cases where the latter exist. Latchup, whose cause we attribute to individual heavy ions, was also observed in some device types.