Soft error rates in static bipolar RAMs

Monte Carlo simulations were applied to obtain the currents generated by α-particles in bipolar static random access memories (RAMs). It was found that the potentially harmful, large charge imbalances take less time to build up, than it typically takes to write the cells. The currents calculated by Monte Carlo procedure serve as input to a circuit simulator. By the combination of the Monte Carlo and the circuit simulations, we obtained a quantitative picture of the soft error exposure of two static bipolar memories, ECL and MTL RAMs. We will show that MTL memories, in contrast to ECL ones, exhibit a large degree of resistance to the α-particle induced soft errors.