Metal-oxide catalyzed epitaxy (MOCATAXY): the example of the O plasma-assisted molecular beam epitaxy of β-(AlxGa1−x)2O3/β-Ga2O3 heterostructures
Metal-oxide catalyzed epitaxy (MOCATAXY): the example of the O plasma-assisted molecular beam epitaxy of β-(AlxGa1−x)2O3/β-Ga2O3 heterostructures
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DOI：
10.7567/apex.11.115503
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发表时间：
2018-10
影响因子：
2.3
通讯作者：
P. Vogt;Akhil Mauze;Feng Wu;B. Bonef;J. Speck
中科院分区：
文献类型：
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作者：
P. Vogt;Akhil Mauze;Feng Wu;B. Bonef;J. Speck
我们证明，通过在生长过程中添加 In 元素，β-(AlxGa1−x)2O3 的 O 等离子体辅助分子束外延的可能生长域和生长速率显着增加。我们通过金属交换催化效应解释了这些增强结果。这种机制使我们能够在缺乏 In 的情况下无法实现的生长条件下合成 β-(AlxGa1−x)2O3/β-Ga2O3 异质结构，从而稳定单斜晶 β 相。我们证明了 β-(AlxGa1−x)2O3 在高达 900 °C 的生长温度下的生长。此外，我们还说明了 β-(AlxGa1−x)2O3 表面上额外的 In 如何充当表面活性剂，从而提高合成的 β-(AlxGa1−x)2O3/β-Ga2O3 异质结构的晶体质量。当 Al 浓度 x = 0.2 时，这些结构具有最高的晶体质量。我们预测，三元 III-O 薄膜合成引入的新型生长模式（以 β-(AlxGa1−x)2O3 为例）适用于各种薄膜材料，其各个成分具有与 β-(AlxGa1−x)2O3 成分所讨论的材料特性类似的材料特性。
We demonstrate a marked increase in the possible growth domain and growth rate of the O plasma-assisted molecular beam epitaxy of β-(AlxGa1−x)2O3, by adding the element In during growth. We explain these enhancement results from a metal-exchange catalytic effect. This mechanism allows us to synthesize β-(AlxGa1−x)2O3/β-Ga2O3 heterostructures at growth conditions that are not accessible in the absence of In, stabilizing the monoclinic β-phase. We demonstrate the growth of β-(AlxGa1−x)2O3 at growth temperatures up to 900 °C. Moreover, we illustrate how additional In on the β-(AlxGa1−x)2O3 surface acts as a surface active agent, improving the crystal quality of the synthesized β-(AlxGa1−x)2O3/β-Ga2O3 heterostructures. These structures are shown to be of the highest crystal quality up to an Al concentration of x = 0.2. We predict the novel growth mode introduced for ternary III–O thin film synthesis — shown by the example of β-(AlxGa1−x)2O3 — to be applicable for a wide range of thin film materials, whose individual constituents possess material properties similar to those discussed for the constituents contributing to β-(AlxGa1−x)2O3.