[17a-PB01-1~25] 21.1 Joint Session K "Wide bandgap oxide semiconductor materials and devices"

[17a-PB01-7] Formation and growth of Ni particle on β-Ga₂O₃(-201) surface: UHV observation

〇(M1)Ririko Takemoto¹, Arihumi Okada¹, Kohei Kadono¹ (1.Kyoto Inst. Tech.)

Keywords:Gallium Oxide, Scanning Tunneling microscopy, Electron beam evapolation

Construction of heterostructures using foreign materials such as NiO is one promising method to implement the devices based on β-Ga₂O₃. To prepare high-quality devices with low-defect interfaces, understanding of initial growth stage is important. In this study, we tried UHV-observation of Ni deposition on the β-Ga₂O₃ substrates and its oxidation. The β-Ga₂O₃(-201) substrate doped with Sn was used as a sample. Ni was deposited on the substrate surface using an electron beam evaporator. The surface structure was observed via scanning tunneling microscopy and noncontact atomic force microscopy. After deposition for 40 s the whole surface of the substrate was covered with Ni particles. The particle diameter was ranging from 1 to 2 nm, which was the same as the case with lower coverages. The STM observations on the surface prepared at room temperature were possible but became difficult after the sample was heated at 750 °C for 20 min. The I-V curve drastically changed as previous study.