Study of tunneling mechanism of Au nanocrystals in HfAlO matrix as floating gate memory

Abstract

A floating gate memory structure containing HfAlO control gate, self-organized Au nanocrystals NCs , and a HfAlO tunnel layer has been fabricated by pulsed-laser deposition. Owing to the charging effects of Au NCs, a significant threshold voltage shift has been obtained and the memory window up to 10.0 V and stored charge density up to 1 1014/cm2 has been achieved. FowlerNordheim tunneling mechanism is used to analyze the capacitance-voltage characteristics of the trilayer memory structure, and it is found that higher density and smaller size of the Au NCs result in a higher tunneling coefficient and a larger memory window.