Patent ID: 7663177

Claim:
A non-volatile memory device, comprising: a substrate; a tunneling dielectric layer provided on the substrate; a composite charge trapping layer provided on the tunneling dielectric layer and having an energy band structure to construct a composition gradient energy band structure with a quantum-well-like energy level structure, wherein the composite charge trapping layer includes a plurality of different materials, the different materials including a first material that includes at least one element and a second material that includes at least one element which is not present in the first material, the first and second materials being disposed in different layers; a block dielectric layer provided on the composite charge trapping layer; and a conductor layer provided on the block dielectric layer; wherein energy band gaps of the tunneling dielectric layer and the block dielectric layer are higher than energy band gap of the charge trapping layer; wherein the materials of the tunneling dielectric layer, the composite charge trapping layer and the block dielectric layer are changed gradually in the sequence of SiO 2 /Al 2 O 3 /Hf x Al y O/TiO 2 /Hf x Al y O/Al 2 O 3 /SiO 2 ; wherein x and y are doping quantities of Hf and Al, respectively, and x and y are not zero; and wherein an energy band gap of SiO 2 is the highest among the four materials SiO 2 , Al 2 O 3 , Hf x Al y O, and TiO 2 , and energy band gaps of Al 2 O 3 and Hf x Al y O 2 are lowered sequentially, and an energy band gap of TiO 2 is the lowest among the four materials, so that the composition gradient energy band structure has a quantum-well-like energy level structure.