Study of Fluorine Incorporation in the Blocking Oxide of MANOS-Type Flash Memory Devices

The effect of high-pressure fluorine annealing (HPFA) at 400°C for 20 min on metal-alumina-nitride-oxide-silicon (MANOS)-type flash memory devices is investigated in this study. After HPFA, X-ray photoelectron spectroscopy data show that the fluorine concentration is nearly 10% at the alumina top surface and decreases with depth. The HPFA replaces Al-O bonds with Al-F bonds in the Al 2 O 3 . This F incorporation results in a reduced leakage current at high electric field (> -16 MV/cm) and improves blocking efficiency. MANOS device characteristics of erase speed, endurance, and retention are all improved. © 2008 The Electrochemical Society. [DOI: 10.1149/1.2978962] All rights reserved.