Epitaxial structure and electronic property of β-Ga2O3 films grown on MgO (100) substrates by pulsed-laser deposition
Epitaxial structure and electronic property of β-Ga2O3 films grown on MgO (100) substrates by pulsed-laser deposition
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DOI：
10.1063/1.4990779
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发表时间：
2017-10-16
影响因子：
4
通讯作者：
Ohtomo, Akira
中科院分区：
文献类型：
--
作者：
Wakabayashi, Ryo;Yoshimatsu, Kohei;Ohtomo, Akira
我们研究了通过脉冲激光沉积在 MgO (100) 基底上异质外延生长 Si 掺杂 Ga2O3 薄膜作为生长温度 (T-g) 的函数，以发现结构和电子特性之间的强相关性。发现这些薄膜含有立方γ相和单斜β相，后者在较高T-g下生长时显示出旋转孪晶域。根据与方形 MgO 晶格的面内外延关系，讨论了稳定 β 相中亚稳态 γ 相和孪晶域结构的形成，而 β 相的结晶度随着 T-g 的降低而单调降低。室温电导率在 T-g 中部表现出最大值，此时 β-Ga2O3 层结晶度相对较高，并且没有双畴结构。此外，MgO 基底上的 β-Ga2O3 薄膜的结晶度和电导率均优于 α-Al2O3 (0001) 基底上的薄膜。在每个基板上达到的最高量的电导率的比率几乎是三个数量级。由 AIP 出版社出版。
We investigated heteroepitaxial growth of Si-doped Ga2O3 films on MgO (100) substrates by pulsed-laser deposition as a function of growth temperature (T-g) to find a strong correlation between the structural and electronic properties. The films were found to contain cubic gamma-phase and monoclinic beta-phase, the latter of which indicated rotational twin domains when grown at higher T-g. The formation of the metastable gamma-phase and twin-domain structure in the stable beta-phase are discussed in terms of the in-plane epitaxial relationships with a square MgO lattice, while crystallinity of the beta-phase degraded monotonically with decreasing T-g. The room-temperature conductivity indicated a maximum at the middle of T-g, where the beta-Ga2O3 layer was relatively highly crystalline and free from the twin-domain structure. Moreover, both crystallinity and conductivity of beta-Ga2O3 films on the MgO substrates were found superior to those on alpha-Al2O3 (0001) substrates. A ratio of the conductivity, attained to the highest quantity on each substrate, was almost three orders of magnitude. Published by AIP Publishing.