Remarkable charge-trapping efficiency of the memory device with (TiO_2)_(0.8)(Al_2O_3)_(0.1) composite charge-storage dielectric

摘要

A memory device p-Si/SiO_2/(TiO_2)_(0.8)(Al_2O_3)_(0.1)(TAO-81)/Al_2O_3/Pt was fabricated, in which a composite of two high-k dielectrics with a thickness of 1 nm was employed as the charge-trapping layer to enhance the charge-trapping efficiency of the memory device. At an applied gate voltage of ±9V, TAO-81 memory device shows a memory window of 8.83 V in its C-V curve. It also shows a fast response to a short voltage pulse of 10~(-5)s. The charge-trapping capability, the endurance, and retention characteristics of TAO-81 memory device can be improved by introducing double TAO-81 charge-trapping layers intercalated by an Al_2O_3 layer. The charge-trapping mechanism in the memory device is mainly ascribed to the generation of the electron-occupied defect level in the band gap of Al_2O_3 induced by the inter-diffusion between TiO_2 and Al_2O_3.