Abstract α-Ga2O3 is a metastable phase of Ga2O3 of interest for wide bandgap engineering since it is isostructural with α-In2O3 and α-Al2O3. α-Ga2O3 is generally synthesised under high pressure (several GPa) or relatively high temperature (∼500 °C). In this study, we report the growth of α-Ga2O3 by low temperature atomic layer deposition (ALD) on sapphire substrate. The film was grown at a rate of 0.48 A/cycle, and predominantly consists of α-Ga2O3 in the form of ( 0001 ) -oriented columns originating from the interface with the substrate. Some inclusions were also present, typically at the tips of the α phase columns and most likely comprising e-Ga2O3. The remainder of the Ga2O3 film – i.e. nearer the surface and between the α-Ga2O3 columns, was amorphous. The film was found to be highly resistive, as is expected for undoped material. This study demonstrates that α-Ga2O3 films can be grown by low temperature ALD and suggests the possibility of a new range of ultraviolet optoelectronic and power devices grown by ALD. The study also shows that scanning electron diffraction is a powerful technique to identify the different polymorphs of Ga2O3 present in multiphase samples.

中文翻译：

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α-Ga 2 O 3 通过低温原子层沉积在蓝宝石上生长

摘要 α-Ga2O3 是 Ga2O3 的亚稳态相，用于宽带隙工程，因为它与 α-In2O3 和 α-Al2O3 具有同构结构。α-Ga2O3 通常在高压（几 GPa）或相对高温（~500 °C）下合成。在这项研究中，我们报告了通过低温原子层沉积 (ALD) 在蓝宝石衬底上生长 α-Ga2O3。该膜以 0.48 A/周期的速率生长，主要由 α-Ga2O3 组成，其形式为 (0001) 取向的柱，源自与衬底的界面。还存在一些夹杂物，通常在 α 相柱的尖端，最有可能包含 e-Ga2O3。Ga2O3 薄膜的其余部分——即靠近表面和 α-Ga2O3 柱之间，是非晶态的。发现该膜具有高电阻，正如未掺杂材料所预期的那样。这项研究表明，α-Ga2O3 薄膜可以通过低温 ALD 生长，并提出了通过 ALD 生长新范围的紫外光电和功率器件的可能性。该研究还表明，扫描电子衍射是一种强大的技术，可以识别多相样品中存在的不同多晶型 Ga2O3。