Memory Effect of Metal-Insulator-Silicon Capacitor with HfO2-Al2O3 Multilayer and Hafnium Nitride Gate

Metal-insulator-silicon capacitors have been fabricated using novel insulators of SiO2/HfO2-Al2O3-HfO2 (HAH)/Al2O3 and metallic HfN gate, exhibiting a program-erasable characteristic. The memory capacitor presents a large memory window of 2.4 V under +12 V program/-14 V erase for 10 ms, no erase saturation, and sufficient electron- and hole-trapping efficiencies such as an electron density of similar to 7 x 10(12) cm(-2) under 13 V program for 0.5 ms and a hole density of similar to 4 x 10(12) cm(-2) under -12 V erase for 0.5 ms. The observed properties are attributed to the introduction of high permittivity atomic-layer-deposited HAH/Al2O3 as well as high work function HfN gate. The related mechanism is addressed accordingly.