Single-Event-Latchup Models Based on Two-Photon-Absorption and Ion Irradiation
Single-Event-Latchup (SEL) is one of the most significant concerns in the area of radiation effects on electronics. It is a condition that causes loss of device functionality due to a single-event induced high-current state. This work develops a strategy to use pulsed-laser measurements, specifically two-photon-absorption (TPA), and ion beam exposures as tools to investigate SEL. In order to establish a precise model in a Monte Carlo simulation tool, MRED, we use broad beam heavy-ion tests at different angles of incidence to calibrate a sensitive volume model. Focused-ion beam measurements and TCAD simulations are used to verify the sensitivity map. A strategy is developed to analyze laser data. Based on this analysis, a pulsed-laser induced SEL sensitivity map, and a cross section versus laser energy curve can be plotted. The sensitive area follows the same pattern as the ion tests, and the cross-section curve can be empirically correlated with the cross section versus LET data from the ion test. Comparing the sensitive depth from the laser data with the one derived from the MRED model for heavy ions, we conclude that pulsed-laser irradiation overestimates the sensitive depth that describes the results of heavy-ion tests. The MRED-based SV model provides refined event-rate estimates in cases where the IRPP model is insufficient to describe critical aspects of the device geometry and/or charge collection. This nested multiple sensitive volume model for ion tests is compared with a simple IRPP model developed from CREME96; the result is similar enough that practical decisions about part selection for these devices can be made using either approach.