Dual-electron-injector-structure electrically alterable read-only-memory modeling studies

The threshold voltage shift of various dual-electron-injector structures (DEIS's) which are composed of chemically vapor-deposited (CVD) stacks of Si-rich SiO
2
, SiO
2
, and Si-rich SiO
2
incorporated into floating polycrystalline-silicon-gate electrically alterable read-only memories (EAROM's) has been studied as a function of write/erase voltages, write/erase times, and the initial charge state of the floating poly-Si gate and compared, to a simple physical model for a variety of different device structures. This model depends on the interface limited (Si-rich-SiO
2
-SiO
2
interfaces) enhanced current injection observed for the dual-electron-injector stacks at moderate gate voltages for both voltage polarities, the changing electric fields in the SiO
2
layers as the floating polycrystalline silicon gate electrode is charged or discharged, and the voltage-dependent capacitance of the dual-electron-injector stack. Good agreement is observed between the experimental data and this model. This model will be the starting point in designing more complicated device arrays for nonvolatile memory applications.