Enhanced charge storage performance in AlTi4Ox/Al2O3 multilayer charge trapping memory devices

The charge-trapping memory devices with the structures p-Si/Al2O3/AlTi4Ox/Al2O3/Pt were fabricated by using atomic layer deposition and RF magnetron sputtering techniques, and a memory window of 6.61V and a high charge-trapping density of 1.29 x 10(13)cm(-2) at gate voltage of +/- 11 V have been obtained. The remarkable charge-trapping effect in the high-k composite oxide layer was ascribed to the electron-occupied defect states formed by the inter-diffusion at the interface of TiO2/Al2O3. An Al2O3 layer intercalated in the charge-trapping layer AlTi4Ox enlarged the memory window to 14.59 V and also improved the data retention property by suppressing the vertical charge migration. (C) 2014 The Japan Society of Applied Physics