Investigation into behavior of mobile ions in storage device using ToF-SIMS

Diffusion behavior of mobile ions in the memory device was successfully visualized as 3D mapping by using ToF-SIMS. In order to realize, we were mainly prepared two kinds of samples. One is a sample written a simple stripe pattern, the other is a sample written a stripe pattern with a density difference. By burning these samples, we were able to estimate the three-dimensional diffusion behavior of the mobile ions. In the temperature range used as usual devices, only Na should be careful because of the large diffusion coefficient and other elements are considered to have little electrical influence.