Mo-Doped La2O3 as Charge-Trapping Layer for Improved Low-Voltage Flash-Memory Performance

Abstract

To utilize the negative conduction-band offset of high-K MoO 3 with respect to Si, the memory characteristics of high-K La 2 O 3 with and without Mo doping as chargetrapping layer were investigated. The cross-sectional structure of the memory was studied by transmission electron microscopy, and the chemical composition of the charge-trapping layer was investigated by X-ray photoelectron spectroscopy. Compared to the memory with pure La 2 O 3 , the one with Mo-doped La 2 O 3 had a significantly large C-V hysteresis window, much higher programming/erasing speeds and better charge retention because the Mo doping introduced many deeper-level traps and the LaMoO charge-trapping layer provided deeper quantum wells.