Transparent Flash Memory using Single Ta2O5 Layer for both Charge Trapping and Tunneling Dielectrics

We report reproducible multibit transparent flash memory in which a single solution-derived Ta2O5 layer is used simultaneously as charge trapping and tunneling layer. This is different from conventional flash cells, where two different dielectric layers are typically used. Under optimized programming/erasing operations, the memory device shows excellent programmable memory characteristics with a maximum memory window of ~10 V. Moreover, the flash memory device shows a stable 2-bit memory performance, good reliability, including data retention for more than 104 sec and endurance performance for more than 100 cycles. The use of a common charge trapping and tunneling layer can simplify advanced flash memory fabrication.