Study of charge trapping as a degradation mechanism in electrically alterable read-only memories

Abstract

Charge trapping in the intervening oxide layers of electrically-alterable read-only memories has been studied for different device configurations incorporating a dual electron injector structure (DEIS). The degradation of the write/erase capability of these devices is associated with electron capture in neutral trapping centers present in both chemical-vapor-deposited and thermal oxides. Annealing the exposed DEIS stack at 1000 °C in N2 results in better cycling capability. The dominant traps in unannealed samples were found to have capture cross sections of σc0x ≊10-16-10-17 cm2, while those in annealed samples have σc0x ≊10-17-10 -18 cm2.