论文标题
通过傅立叶成像微体积测定法对去角质范德华材料的厚度映射和层数鉴定
Thickness mapping and layer number identification of exfoliated van der Waals materials by Fourier imaging micro-ellipsometry
论文作者
论文摘要
随着单一到几层去角质的范德华异质结构的性质在很大程度上取决于其厚度，因此，准确的厚度测量在他们的研究中必须进行。通常使用的原子力显微镜和拉曼光谱技术可能具有侵入性并产生不确定的结果。另外，光谱椭圆法受到数十亿微分辨率和/或低数据采集速率的限制，从而抑制了其用于微尺度去角质片的利用。在这项工作中，我们演示了一个傅立叶成像光谱微欧洲纤维仪，具有低5微米的侧向分辨率以及快速数据采集速率，并在单一，双层烯，六边形的氮化物和过渡金属二十甲基二十甲基（MosdiChalcogenice）（Moscogeniide（Moss2）2，Ws2，Ws2，Ws2，Ws2，Ws2，Ws2，WS 2，WS-Ws2，Wws2，ws2，WWS2，WWS2，WWS2，WWS2，WES 2，六边形的六边形硼烯，六边形硼硼级，六边形硼烯，hexagonal boron boron和Trilayer上均准确且一致的厚度映射。我们表明，光学显微镜集成的椭圆机还可以在微尺度薄片上绘制微小的厚度变化。此外，我们的系统解决了识别单层厚HBN的相关问题。
As properties of mono- to few layers of exfoliated van der Waals heterostructures are heavily dependent on their thicknesses, accurate thickness measurement becomes imperative in their study. Commonly used atomic force microscopy and Raman spectroscopy techniques may be invasive and produce inconclusive results. Alternatively, spectroscopic ellipsometry is limited by tens-of-microns lateral resolution and/or low data acquisition rates, inhibiting its utilization for micro-scale exfoliated flakes. In this work, we demonstrate a Fourier imaging spectroscopic micro-ellipsometer with sub-5 microns lateral resolution along with fast data acquisition rate and present angstrom-level accurate and consistent thickness mapping on mono-, bi- and trilayers of graphene, hexagonal boron nitride and transition metal dichalcogenide (MoS2, WS2, MoSe2, WSe2) flakes. We show that the optical microscope integrated ellipsometer can also map minute thickness variations over a micro-scale flake. In addition, our system addresses the pertinent issue of identifying monolayer thick hBN.
