Retention and endurance characteristics of HCl-annealed and unannealed MNOS capacitors

Abstract

MNOS capacitors (metal-nitrite-oxide-semiconductor) have been used to study the effects of memory oxide growth and post-oxidation annealing conditions on retention and endurance of MNOS devices. Results of this study indicate that write/erase cycling causes a decrease in memory window size after 10 5 cycles, a shift of the memory window center toward more positive values of threshold voltage, and an increase in surface state density for cycling above 10 6 cycles. The retention data presented indicates that the memory window decay rate for ±25 V writing pulses is only a function of the initial window size. The collapse of the memory window to zero volts is predicted to occur after 10 16 sec for native oxide devices and after 10 18 sec for thermal oxide devices. HCl annealing of the memory oxide does not have a significant effect on either endurance or retention.