Transient conductive path induced by a Single ion in 10 nm SiO/sub 2/ Layers

Large charge loss can happen in isolated conductive lines when hit by a single high linear energy transfer (LET) ion. We have demonstrated this phenomenon by using floating gate (FG) memory arrays, which allowed us to study it on the basis of a large statistical set of data. Charge loss is by far larger than that expected from a simple generation-recombination model. FG's hit by ions experience a charge loss linearly dependent on ion LET and on the electric field. We are proposing a semi-empirical model based on the idea that a conductive path assimilable to a resistance connects the FG to the substrate during the time (10/sup -14/ s) needed for electrons to escape the tunnel oxide. The model is fully consistent with a broad range of theoretical and experimental results, and has excellent fitting capabilities.