Superior characteristics of nitridized thermal oxide grown on polycrystalline silicon

Polycrystalline silicon dioxide (poly-oxide) nitridized at high temperatures in ammonia ambient has been characterized by using ramp current-voltage (I-V) and constant current stressed voltage-time (V-t) measurements. It is found that the nitridized poly-oxide has less leakage current and stronger dielectric field strength as compared to conventional poly-oxide. These advantages are attributed to the slightly increased trapping effect and the less severe asperity effect of the nitridized poly-oxide. It has been shown that the nitridized poly-oxide is a good material for applications in high density electrically erasable and programmable read only memory (EEPROM) devices.