2-inch semi-polar (112&cmb.macr;2) AlN templates prepared by high-temperature hydride vapor phase epitaxy

• Published in: CrystEngComm 2024-06, Vol.26 (25), p.3383-3387
• Main Authors: Liu, Ting, Fang, Chunlei, Sun, Maosong, Chen, Minghao, Ji, Jianli, Shen, Zhijie, Lu, Yong, Tan, Shuxin, Zhang, Jicai
• Format: Article
• Language: English
• Subjects: Buffer layers; Emitters; Epitaxial growth; High temperature; Hydrides; Low temperature; Sapphire; Single crystals; Substrates; Two dimensional flow; Vapor phase epitaxy; Vapor phases
• ISSN: 1466-8033; 1466-8033
• DOI: 10.1039/d4ce00335g

Single-crystal semi-polar (112&cmb.macr;2) AlN films are grown on 2-inch m -plane sapphire substrates by high-temperature hydride vapor phase epitaxy (HVPE). The introduction of the sapphire nitridation pretreatment and low-temperature AlN buffer layer suppresses the formation of undesired (101&cmb.macr;3) and (101&cmb.macr;1) AlN, leading to the desired single-crystal (112&cmb.macr;2) AlN film. The high growth temperature promotes a shift in growth mode from three-dimensional islands to two-dimensional step flow. This facilitates grain coalescence, resulting in the formation of well-defined macro steps on the (112&cmb.macr;2) AlN surface. The 9.02 μm-thick (112&cmb.macr;2) AlN film exhibits excellent crystalline quality, as evidenced by the narrow full widths at half maximum of 547′′ and 634′′ for the X-ray rocking curves measured along the [112&cmb.macr;3] AlN and [11&cmb.macr;00] AlN directions, respectively. The surface of the 2-inch (112&cmb.macr;2) AlN film is free of cracks and unmerged grains, providing a suitable substrate for the subsequent epitaxial growth of (112&cmb.macr;2) AlN light emitter layers. Single-crystal semi-polar (112&cmb.macr;2) AlN films are grown on 2-inch m -plane sapphire substrates by high-temperature hydride vapor phase epitaxy (HVPE).