A study of the influence of tunnel oxide thickness on the performance of flash memory based on ion‐beam synthesized silicon nanocrystals

Abstract

AbstractIn this work, we have fabricated silicon nanocrystal (nc‐Si) based Flash memories with two different tunnel‐oxide thicknesses (3 and 7 nm). The nc‐Si is synthesized with very‐low energy ion implantation and subsequent thermal annealing. The endurance and retention characteristics of the memory devices are investigated. For the thick tunnel oxide (7 nm), a memory window of ∼0.5 V is achieved with the program/erase (P/E) operation at +12 V/–12 V for 1 ms; and for the thin tunnel oxide (3 nm), a memory window of ∼0.6 V can be obtained at +9 V/–9 V for 1 μs. For both oxide thicknesses, good endurance with a small threshold voltage drift after 105 P/E cycles is observed. For the thick and thin tunnel oxides, the device is expected to show ∼20% and ∼70% charge loss after 10 years, respectively. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)