Angular Dependence of Heavy-Ion Induced Errors in Floating Gate Memories

We studied the angular dependence of heavy-ion induced errors and threshold voltage shifts in Flash memories. Combining experiments and Geant4-based simulations, we provide new insight about the sensitive volume in floating gate cells. At high LET, the sensitive volume for cells belonging to the heavy-ion induced secondary peak corresponds to a large part of the floating gate. The sensitive volume for upsets may be larger or smaller, depending on the relative position of the secondary peak with respect to the relevant reference voltage.