六方氮化硼(Hexagonal boron nitride, h-BN)薄膜在二維材料應用中極有潛力，並且近年來也被發現擁有室溫單光子發光的特徵，在量子光學也有應用潛力，而目前成長出品質良好h-BN 的團隊皆使用化學氣象磊晶成長在金屬基板上，如果需要應用則需要轉移至其他基板上，不僅可能產生缺陷，也會有轉移後晶格不匹配的問題，因此我們的目標是將六方氮化硼直接成長在可應用的基板上，避免轉移所會遇到的各種問題。
本論文先在碳化矽基板上成長出適合之石墨烯基板，石墨烯基板以SEM 以及AFM 測量表面樣貌，並使用Raman 光譜測量石墨稀特徵，最後得到真空中1375℃，8 分鐘的成長條件，台階完整性較佳，並使用此基板做為成長h-BN 之基板。成長完的h-BN，一樣利用SEM 及AFM 測量表面形貌，並得到h-BN 成長呈現六角形，並且橫向成長擁有一穩定速度，當成長層平均數較高時，h-BN 會因為熱膨脹係數不同而產成皺褶，並從Raman 訊號額外的藍移中推測這些皺褶會提供額外的壓縮應力；成長平均層數較低的h-BN，並不會有皺褶，Raman 訊號也測得無應力的1367cm^-1特徵訊號，且從ARPES 中測得單一一條清晰的π-band 能帶，代表成長出單層且單晶的高品質h-BN。另外使用TEM 測量成長18hr 的h-BN 橫切面，得到成長層數約為4層，並且式層狀堆疊的結構。最後將h-BN 以RIE 處裡，得到與文獻中相似的單光子發光特徵。

Hexagonal boron nitride (h-BN) have great potential in 2D material application and quantum emitter. In recent study, most high quality h-BN was grown on metal by chemical vapor deposition (CVD). Our goal is grow h-BN on graphene/SiC substrate directly by plasma-assisted molecular beam epitaxy (PA-MBE), and we successfully grow high quality h-BN. We check morphology of h-BN by scanning electron microscope (SEM) and Atomic force microscope (AFM), calculate number of layer by SEM and detect phonon vibration mode of h-BN by Raman spectroscopy. Finally, angle resolved photoemission spectroscopy (ARPES) verify that h-BN is single crystal.

[1] A. K. Geim and I. V. Grigorieva, "Van der Waals heterostructures," Nature, vol. 499, pp. 419-425, 2013.
[2] Mak, K. and Shan, J., "Photonics and optoelectronics of 2D semiconductor transition metal dichalcogenides," Nature Photon, vol. 10, pp. 216-226, 2016.
[3] Dean, C., Young, A., Meric, I. et al, "Boron nitride substrates for high-quality graphene electronics," Nature Nanotech, vol. 5, pp. 722-726, 2010.
[4] He, Y., Clark, G., Schaibley, J. et al., "Single quantum emitters in monolayer semiconductors," Nature Nanotech, vol. 10, pp. 497-502, 2015.
[5] Toan Trong Tran et al., "Robust Multicolor Single Photon Emission from Point Defects in Hexagonal Boron Nitride," ACS nano, pp. 7331-7338, 2016.
[6] Igor Aharonovich, Dirk Englund and Toth Milos, "Solid-state single-photon emitters," Nature Photon, vol. 10, pp. 631-641, 2016.
[7] Tran, T., Bray, K., Ford, M. et al., "Quantum emission from hexagonal boron nitride monolayers," Nature Nanotech, vol. 11, pp. 37-41, 2015.
[8] Joo Song Lee et al, "Wafer-scale single-crystal hexagonal boron nitride film via self-collimated grain formation," Science, vol. 362, pp. 817-821, 2018.
[9] Wang, L., Xu, X., Zhang, L. et al., "Epitaxial growth of a 100-square-centimetre single-crystal hexagonal boron nitride monolayer on copper," Nature, vol. 570, pp. 91-95, 2019.
[10] Nasim Alem et al., "Atomically thin hexagonal boron nitride probed by ultrahigh-resolution transmission electron microscopy," Phys. Rev. B, vol. 80, p. 155425, 2009.
[11] Woods, C., Britnell, L., Eckmann, A. et al., "Commensurate–incommensurate transition in graphene on hexagonal boron nitride," Nature Phys, vol. 10, pp. 451-456, 2014.
[12] Cassabois, G., Valvin, P. & Gil, B., "Hexagonal boron nitride is an indirect bandgap semiconductor," Nature Photon, vol. 10, pp. 262-266, 2016.
[13] Jang, S., Youn, J., Song, Y. et al., "Synthesis and Characterization of Hexagonal Boron Nitride as a Gate Dielectric," Sci Rep, vol. 6, p. 30449, 2016.
[14] Yoichi Kubota, Kenji Watanabe, Osamu Tsuda, Takashi Taniguchi, "Deep Ultraviolet Light-Emitting Hexagonal Boron Nitride Synthesized at Atmospheric Pressure," vol. 317, pp. 932-934, 2007.
[15] Lu Hua Li et al., "Strong Oxidation Resistance of Atomically Thin Boron Nitride Nanosheets," ACS Nano, vol. 8, pp. 1457-1462, 2014.
[16] Park Systems, "Basic contact AFM & Dynamic Force Microscopy (DFM)".
[17] Park Systems, “Phase Imaging / Phase Detection Microscopy (PDM)”.
[18] NC state university, "JEOL 2000FX Handbook".
[19] Emtsev, K., Bostwick, A., Horn, K. et al, "Towards wafer-size graphene layers by atmospheric pressure graphitization of silicon carbide," Nature Mater, vol. 8, pp. 203-207, 2009.
[20] J. Röhrl, M. Hundhausen, K. V. Emtsev, Th. Seyller, R. Graupner, and L. Ley, "Raman spectra of epitaxial graphene on SiC(0001)," Appl. Phys. Lett., vol. 92, p. 201918, 2008.
[21] Pease, R. S., "An X-ray study of boron nitride," Acta Crystallographica, vol. 5, pp. 356-361, 1952.
[22] Harris, Gary Lynn, Properties of silicon carbide, 1995, pp. 170-180.
[23] D.K.L. Tsang, B.J. Marsden, S.L. Fok, G. Hall, "Graphite thermal expansion relationship for different," Carbon, vol. 43, pp. 2902-2906, 2005.
[24] Qiran Cai et al., "Raman signature and phonon dispersion of atomically thin boron nitride," Nanoscale, vol. 9, pp. 3059-3067, 2017.
[25] Ch. Androulidakis et al., "Strained hexagonal boron nitride: Phonon shift and Grüneisen parameter," Physical Review B, vol. 97, p. 241414.
[26] Henck H et al., "Direct observation of the band structure in bulk hexagonal boron nitride," Phys. Rev. B, vol. 95, p. 085410, 2017.
[27] Parravicini, E. Doni and G. P., "Energy Bands and Optical Properties oI Hexagonal Boron Nitride and Graphite," Nuovo Cim. B, vol. 64, p. 117, 1969.
[28] Quan Huang, Dongli Yu et al., "First-principles study of O-BN: A sp3-bonding boron nitride allotrope," Journal of Applied Physics, vol. 112, p. 053518, 2012.