[20p-B103-1~19] 6.1 Ferroelectric thin films

[20p-B103-7] Study on oxygen impurity in (Al,Sc)N thin films fabricated by sputtering technique

〇Kota Hasegawa^1,2, Takao Shimizu², Takeo Ohsawa², Isao Sakaguchi^1,2, Naoki Ohashi^1,2,3 (1.Kyushu Univ., 2.NIMS, 3.Tokyo tech)

Keywords:ferroelectric, aluminum nitride, XPS

Wurtzite(WZ)-type (Al,Sc)N thin films were fabricated by a reactive RF magnetron sputtering method on single crystal substrates of Nb 0.5wt% doped SrTiO₃ with a mirror polished (111) face. The obtained films exhibited ferroelectricity, and it was confirmed that their coercive electric field decreased with the increase of Sc concentration. On the other hand, x-ray photoemission measurements revealed that the amount of oxygen impurity in the films increased with increasing Sc content. We will discuss the effect of oxygen impurity upon structure and properties of the films as well as the origin of the impurity.