HEAVY-ION AND PROTON-INDUCED SINGLE EVENT MULTIPLE UPSET

Individual ionizing heavy ion events are shown to cause two or more ad jacent memory cells to change logic states in a high density CMOS SRAM . A majority of the upsets produced by normally incident heavy ions ar e due to single particle events that causes a single cell to upset. Ho wever, for grazing angles a majority of the upsets produced by heavy-i on irradiation are due to single-particle events that cause two or mor e cells to change logic states. Experimental evidence of a single prot on-induced spallation reaction that causes two adjacent memory cells t o change logic states is presented. Results from a dual volume Monte-C arlo simulation code for proton-induced single-event multiple upsets a re within a factor of three of experimental data for protons at normal incidence and 70 degrees.