Effects of Single Neutron Interactions in Silicon Integrated Circuits

Measurements of the permanent effects of single fast neutron interactions in silicon depletion regions are reported for the first time. Increases in dark current density by as much as two orders of magnitude were observed for individual cells in an image sensor bombarded with 14-MeV neutrons. Single damage events and the distribution of a large number of events were measured. Experimental results are in good agreement with model calculations and statistical expectations. Long-term annealing data for single events are used in conjunction with previous macroscopic short-term annealing results to predict the early-time impact of individual damaged regions. Implications of the present results for VLSI/ULSI circuits are discussed, and examples of cases in which problems may occur are given. An approach is presented for assessing the susceptibility of any integrated circuit to the permanent effects of single neutron interactions.