Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA.
ACS Nano. 2011 Sep 27;5(9):7303-9. doi: 10.1021/nn202141k. Epub 2011 Aug 1.
The growth of large-area hexagonal boron nitride (h-BN) monolayers on catalytic metal substrates is a topic of scientific and technological interest. We have used real-time microscopy during the growth process to study h-BN chemical vapor deposition (CVD) from borazine on Ru(0001) single crystals and thin films. At low borazine pressures, individual h-BN domains nucleate sparsely, grow to macroscopic dimensions, and coalescence to form a closed monolayer film. A quantitative analysis shows borazine adsorption and dissociation predominantly on Ru, with the h-BN covered areas being at least 100 times less reactive. We establish strong effects of hydrogen added to the CVD precursor gas in controlling the in-plane expansion and morphology of the growing h-BN domains. High-temperature exposure of h-BN/Ru to pure hydrogen causes the controlled edge detachment of B and N and can be used as a clean etching process for h-BN on metals.
在催化金属衬底上生长大面积六方氮化硼（h-BN）单层是一个备受科学和技术关注的课题。我们在生长过程中使用实时显微镜研究了从硼烷在 Ru(0001)单晶和薄膜上的化学气相沉积（CVD）。在低硼烷压力下，单个 h-BN 畴稀疏地成核，生长到宏观尺寸，并合并形成封闭的单层膜。定量分析表明，硼烷吸附和离解主要发生在 Ru 上，而被 h-BN 覆盖的区域的反应性至少低 100 倍。我们发现，在 CVD 前体气体中添加氢气对控制生长的 h-BN 畴的平面内膨胀和形态有很强的影响。高温下将 h-BN/Ru 暴露于纯氢气中会导致 B 和 N 的可控边缘脱离，可作为金属上 h-BN 的清洁刻蚀工艺。
