High-temperature molecular beam epitaxy of hexagonal boron nitride layers
High-temperature molecular beam epitaxy of hexagonal boron nitride layers
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DOI：
10.1116/1.5011280
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发表时间：
2018-03-01
影响因子：
1.4
通讯作者：
Novikov, Sergei V.
中科院分区：
文献类型：
--
作者：
Cheng, Tin S.;Summerfield, Alex;Novikov, Sergei V.
六方氮化硼（hBN）的生长和性能最近引起了人们的广泛关注，这是由于其在石墨烯基单层厚二维（2D）结构中的应用，同时作为用于深紫外器件（DUV）应用的宽带隙材料。作者介绍了他们的结果，在高温等离子体辅助分子束外延（PA-MBE）的hBN单层高度定向热解石墨基板。他们的结果表明，在类似于1390摄氏度的温度下，PA-MBE生长可以实现单层和少层厚的hBN，同时控制hBN覆盖率和原子级平坦的hBN表面，这对于hBN层的2D应用至关重要。hBN单层覆盖率可以通过PA-MBE生长温度、时间和B：N流量比来重复控制。在更高的B：N通量比下已经实现了显著更厚的hBN层。作者观察到，通过将生长温度从1390 ℃降低到1080 ℃，hBN的厚度从40 nm逐渐增加到70 nm。然而，通过将MBE生长温度降低到1250摄氏度以下，作者观察到hBN层的光学性质迅速退化。因此，高于1250摄氏度的高温PA-MBE是用于2D和DUV应用的高质量hBN层生长的可行方法。(C)2018年作者。
The growth and properties of hexagonal boron nitride (hBN) have recently attracted much attention due to applications in graphene-based monolayer thick two dimensional (2D)-structures and at the same time as a wide band gap material for deep-ultraviolet device (DUV) applications. The authors present their results in the high-temperature plasma-assisted molecular beam epitaxy (PA-MBE) of hBN monolayers on highly oriented pyrolytic graphite substrates. Their results demonstrate that PA-MBE growth at temperatures similar to 1390 degrees C can achieve mono-and few-layer thick hBN with a control of the hBN coverage and atomically flat hBN surfaces which is essential for 2D applications of hBN layers. The hBN monolayer coverage can be reproducible controlled by the PA-MBE growth temperature, time and B:N flux ratios. Significantly thicker hBN layers have been achieved at higher B: N flux ratios. The authors observed a gradual increase of the hBN thickness from 40 to 70 nm by decreasing the growth temperature from 1390 to 1080 degrees C. However, by decreasing the MBE growth temperature below 1250 degrees C, the authors observe a rapid degradation of the optical properties of hBN layers. Therefore, high-temperature PA-MBE, above 1250 degrees C, is a viable approach for the growth of high-quality hBN layers for 2D and DUV applications. (C) 2018 Author(s).