Stack gate PZT/Al2O3 one transistor ferroelectric memory

We have developed a single transistor ferroelectric memory using stack gate PZT/Al/sub 2/O/sub 3/ structure. For the same /spl sim/40 /spl Aring/ dielectric thickness, the PZT/Al/sub 2/O/sub 3//Si gate dielectric has much better C-V characteristics and larger threshold voltage shift than those of PZT/SiO/sub 2//Si. Besides, the ferroelectric MOSFET also shows a large output current difference between programmed on state and erased off state. The <100 us erase time is much faster than that of flash memory where the switching time is limited by erase time.