Dynamic behavior of charge in MOS devices embedded with Pt and Au nanoparticles

We study two types of MOS structures that contain nanoparticles embedded between a silicon dioxide layer and a hafnium capping-oxide layer; the first structure contains Au nanoparticles while the second contains Pt nanoparticles. We compare the charge injection and storage mechanisms in these structures using electrical measurements and we demonstrate that the charge injection takes place under low electric field for both devices. We also find that the MOS structures with Au nanoparticles present significantly larger retention times in comparison to Pt nanoparticles; this behavior is attributed to the formation of deep donor states due to a limited Au diffusion in the dielectric layer.