금속씨앗층과 $N_2$ 플라즈마 처리를 통한 Al/CeO$_2$/Si 커패시터의 유전 및 계면특성 개선

Improvement of dielectric and interface properties of Al/CeO$_2$/Si capacitor by using the metal seed layer and $N_2$ plasma treatment

In this paper, we investigated a feasibility of cerium oxide(CeO$_2$) films as a buffer layer of MFIS(metal ferroelectric insulator semiconductor) type capacitor. CeO$_2$ layer were Prepared by two step process of a low temperature film growth and subsequent RTA (rapid thermal annealing) treatment. By app1ying an ultra thin Ce metal seed layer and N$_2$ Plasma treatment, dielectric and interface properties were improved. It means that unwanted SiO$_2$ layer generation was successfully suppressed at the interface between He buffer layer and Si substrate. The lowest lattice mismatch of CeO$_2$ film was as low as 1.76% and average surface roughness was less than 0.7 m. The Al/CeO$_2$/Si structure shows breakdown electric field of 1.2 MV/cm, dielectric constant of more than 15.1 and interface state densities as low as 1.84${\times}$10$\^$11/ cm$\^$-1/eV$\^$-1/. After N$_2$ plasma treatment, the leakage current was reduced with about 2-order.