Zhang, DujiaoWu, FeihongYing, QiGao, XinyuLi, NanWang, KejingYin, ZongyouCheng, YonghongMeng, Guodong2020-02-182050-7526http://hdl.handle.net/1885/201757The outstanding thermal properties, mechanical properties and large optical bandgap of hexagonal boron nitride (h-BN) make it very attractive for various applications in ultrathin 2D microelectronics. However, the synthesis of large lateral size and uniform h-BN thin films with a high breakdown strength still remains a great challenge. Here, we comprehensively investigated the effect of growth conditions on the thickness of h-BN films via low pressure chemical vapor deposition (LPCVD). By optimizing the LPCVD growth parameters with electropolished Cu foils as the deposition substrates and developing customized `` enclosure'' quartz-boat reactors, we achieved thickness-tunable (1.50-10.30 nm) growth of h-BN thin films with a smooth surface (RMS roughness is 0.26 nm) and an ultra-large area (1.0 cm x 1.0 cm), meanwhile, the as-grown h-BN films exhibited an ultra-high breakdown strength of similar to 10.0 MV cm(-1), which is highly promising for the development of electrically reliable 2D microelectronic devices with an ultrathin feature.This work was supported by the China Postdoctoral Science Foundation (Grant No. 2016M602820), the National Natural Science Foundation of China (Grant No. 51607138), the Youth Innovation Foundation of State Key Laboratory of Electrical Insulation and Power Equipment (Grant No. EIPE17312), the Research Foundation of State Key Laboratory of Intense Pulsed Radiation Simulation and Effect (Grant No. SKLIPR.1512) and the Innovative Research Group of National Natural Science Foundation of China (Grant No. 51521065).10 pagesapplication/pdfen-AU© The Royal Society of Chemistry 20192019-02-2110.1039/c8tc05345f2019-11-25