[17p-P06-1~11] 21.1 Joint Session K "Wide bandgap oxide semiconductor materials and devices"

[17p-P06-2] SPM study on initial stage of epitaxial growth of NiO on β-Ga₂O₃(-201) surface

〇(B)Yusuke Seki¹, Arifumi Okada¹, Yuki Kajita¹, Hiroyuki Nishinaka¹, Romualdo A. Ferreyra², Daisuke Ueda³, Kohei Kadono¹ (1.Kyoto Inst. Tech, 2.Univ. de San Martin, 3.cLPS, Nagoya Univ)

Keywords:galium oxide, scanning probe microscopy, surface morphology

Wide-gap semiconductor β-Ga₂O₃ is one of candidate materials for next-generation power devices. However, p-type conduction of this material is hard to achieve. Therefore, development of heteroepitaxial growth of certain materials which can be p-type semiconductor such as NiO is essential to realize the Ga₂O₃-based devices. In this study, surface observation of clean- and NiO-deposited β-Ga₂O₃(-201) surfaces using scanning tunneling and atomic force microscopies were performed. Besides the observation some spectroscopic measurements were also performed. Clean surface annealed in air at 400ºC showed steps and terraces keeping electric conductivity. On the other hand, after NiO deposition by means of mist CVD, islands covered the surface were observed. The islands have about 10 nm of in-plane size and below 1 nm of height. The in-plane size was considered to be mainly caused by lattice misfit between NiO(111) and β-Ga₂O₃(-201).