ABSTRACT
Data operation in nanocrystal (NC) flash memories is achieved by controlling charge transfer between NCs embedded within the gate oxide and the channel of a metal-oxide-semiconductor field-effect transistor (MOSFET). It is well known that during programming operations, the tunneling time of a single electron from the MOSFET channel into a NC is of the order of tens to hundreds of nanoseconds, depending on the tunneling oxide thickness. In the erase operation, confined electrons tunnel from the NCs to the continuum density of states of the bulk substrate. Programming performance can be engineered by optimizing parameters such as NC shape and size, tunneling barrier thickness, and control oxide thickness. The mandatory condition for achieving optical programming is that out tunneling of the escaping particle must be faster than the recombination lifetime of the confined exciton.
