Non-volatile doubly stacked Si dot memory

In the Si dot memory, the realization of a long retention time is the most critical issue, since the tunnel oxide is very thin. So as to realize a long retention time without losing high-speed w/e in Si dot memory, we propose a novel Si dot memory whose floating gates are doubly stacked Si dots. A long retention time is possible, since the charge leak between the upper dots and the channel is suppressed due to quantum confinement and Coulomb blockade in the lower dot. Simultaneously, a high-speed w/e is possible, since the leak suppression is useful only in a low voltage region. Therefore, Si double dot memory is very promising for low-power non-volatile memory.