Heteroepitaxy of corundum-structured α-Ga2O3 thin films on α-Al2O3 substrates by ultrasonic mist chemical vapor deposition
Heteroepitaxy of corundum-structured α-Ga2O3 thin films on α-Al2O3 substrates by ultrasonic mist chemical vapor deposition
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DOI：
10.1143/jjap.47.7311
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发表时间：
2008-09-01
影响因子：
1.5
通讯作者：
Fujita, Shizuo
中科院分区：
文献类型：
--
作者：
Shinohara, Daisuke;Fujita, Shizuo
与Ga 2 O3在蓝宝石上呈现异质晶体结构即β-镓结构（在单斜晶系中）的强烈趋势相反，在蓝宝石（α-Al 2 O3）衬底上外延获得α相即β-镓结构（在三角晶系中）的Ga 2 O3薄膜。这一结果对于高质量薄膜是有利的，并且是由于在430-470摄氏度的低温下通过雾状化学气相沉积（CVD）进行的生长。α-Ga 2 O 3膜在其X射线衍射摇摆曲线中具有窄的半峰全宽（FWHMs），例如，约60弧秒。表面的均方根（RMS）粗糙度小至1 nm。光学带隙能量为5.3eV。并且该膜在近紫外和可见光区域几乎完全透明。在蓝宝石衬底上外延生长α-Ga 2 O 3薄膜有利于氧化物光学和电子器件的制备。
Ga2O3 thin films of the alpha-phase, that is, the corundum structure (in the trigonal system), have been epitaxially obtained on sapphire (alpha-Al2O3) substrates, in contrast to the strong tendency of Ga2O3 to assume a heterogeneous crystal structure, that is, the beta-gallia structure (in the monoclinic system) on sapphire. This result is advantageous for high-quality films and is due to the growth by mist chemical vapor deposition (CVD) at low temperatures of 430-470 degrees C. The alpha-Ga2O3 films have narrow full-widths at half maximum (FWHMs) in their X-ray diffraction rocking curves, for example, about 60 arcsec. The root mean square (RMS) roughness of the surface was as small as 1 nm. The optical band gap energy obtained was 5.3eV. and the films were almost completely transparent in the near-ultraviolet and visible regions. The epitaxial growth of alpha-Ga2O3 films on sapphire is beneficial for the fabrication of oxide optical and electronic devices.