Multilevel programming at a low-voltage step using junction avalanche hot carrier injections

Abstract

A highly efficient program method is proposed for multilevel programming with a low-voltage step in a conventional polycrystalline silicon-oxide-nitride-oxide-silicon structure. This method uses junction avalanche hot carriers for charge storage in the nitride layer. A multilevel storage is easily obtained by using a low-voltage step of 0.1 V at each level of the three programmed states along with a fast program time of 1 mu s. In addition, a localized charge-injection near the junction edge is clearly observed with an acceptable read margin and threshold voltage difference between the forward and the reverse read at the three programmed states. (C) 2011 American Institute of Physics. [doi:10.1063/1.3579247]