Different approaches for reliability enhancement of p-channel flash memory

In this paper, we will demonstrate two different strategies for designing p-channel flash memories, for achieving better reliability, in particular data retention and drain-disturb. The first one is by using a gate-engineering approach and the other one is using a newly developed substrate bias enhanced Avalanche Hot Electron (AHE) injection programming scheme. For the former, a p-doped floating gate on both p-channel flash cells can be achieved with superior data retention characteristics as well as a 3-order improvement of the drain disturb. For the latter, it exhibits much higher speed and much lower voltage for programming, and very good drain disturb characteristics.