A new memory element based on silicon nanoclusters in a ZrO2 insulator with a high permittivity for electrically erasable read-only memory

The write and erase function and the data retention characteristics of a memory element designed to be used in electrically erasable read-only memory and based on a silicon-oxide-(silicon dot)-oxide-polysilicon structure, in which either a SiO2 insulator or a ZrO2 high-permittivity insulator are used as blocking oxides, are simulated. It is established that the use of the high-permittivity insulator gives rise to a number of effects: spurious injection from poly-Si is reduced; the electric field in the tunneling oxide increases; it becomes possible to increase the thickness of the tunneling insulator and, consequently, to increase the data retention time; and lower voltages for the write and erase functions can be used. Programming with a pulse of ±11 V possessing a width of 10 ms makes it possible to retain a memory window of ∼3 V for 10 years.