Presentation Information
[1F09]Photoelectron holographic study of atomic site occupancy of the Si dopant in k-Ga2O3(001)
*Yoshiyuki YAMASHITA1,2, YuHua TSAI1,2, Yusuke HASHIMOTO3, Tomohiro MATSUSHITA3, Piero MAZZOLINI4 (1. National Institute for Materials Science, 2. Kyusyu University, 3. Nara Institute of Science and Technology, 4. University of Parma)
For Ga2O3, there are six crystal polymorphs: α-, β-, δ-, γ-, ε-, and κ-Ga2O3. Among them, β-Ga2O3 has received the most attention due to its highest thermal stability. Recently, the orthorhombic κ-Ga2O3 has gained attention due to its large spontaneous polarization and its ferroelectricity. For κ-Ga2O3, Si is usually used as the dopant to control the electrical properties. There are three inequivalent Ga atomic sites as the dopant sites in κ-Ga2O3; octahedral (Octa), pentahedral (Penta), and tetrahedral (Tetra). Therefore, to control the electrical properties, the atomic site occupancy of Si dopant in Si-doped κ-Ga2O3 should be clarified. In the present study, we investigated the atomic site occupancy of the Si dopants for Si-doped κ-Ga2O3 using photoelectron holography (PEH). The Si-doped κ-Ga2O3 epitaxial layers were grown on a c-plane sapphire substrates prepared by the MOVPE method. The PEH measurements were performed at the BL25SU beamline of SPring-8.By comparing the experimental and the simulated PEHs, the ratios for the Tetra, Penta, and Octa SiGa sites are estimated to be 51.0%, 35.2%, and 13.8%, respectively.