An estimate of error rates in integrated circuits at aircraft altitudes and at sea level

Negative muons nearing the end of their range can undergo capture in the nucleus, disintegrate, and damage microelectronics. Although there are large numbers of muons produced in the atmosphere by cosmic rays, there have been no experimental data evaluating the vulnerability of integrated circuits to stopping muons. Changes in bit states (errors) in 4K NMOS static RAMs have been obtained with accelerator beams of positive and negative muons nearing the end of their range, along with the corresponding microdosimetric spectra. These data and earlier results are used to estimate both absolute error rates and the relative contributions of different particle types at 10 km (a nominal aircraft altitude) and at sea level. The calculation indicates that typical error rates at 10 km would be about 10 errors per megabit per year, only slightly less than the estimated rate for satellite altitudes.