SIMPLE-MODEL FOR PROTON-INDUCED LATCH-UP

Computer simulations show, that the strong angular dependence exhibite d by proton-induced single-event latch-up can be explained by a simple mechanism. Latch-up occurs if, and only if, more than some threshold amount of energy is deposited within the sensitive volume. A procedure for determining the SEU parameters by comparing SEU cross sections an d CUPID simulations at different incident energies and angles of incid ence is described. The thickness of the sensitive volume and the value of the critical charge determined for the NEC 4464, a 64 Kbit CMOS SR AM, agrees with the measured thickness of the p-cell and the value of the threshold LET determined with heavy ions.