Hexagonal boron nitride (h-BN) has recently been in the spotlight
due to its numerous applications including its being an ideal substrate for twodimensional
electronics, a tunneling material for vertical tunneling devices, and a
growth template for heterostructures. However, to obtain a large area of h-BN film
while maintaining uniform thickness is still challenging and has not been realized.
Here, we report the systematical study of h-BN growth on Pt foil by using low pressure chemical vapor deposition with a borazine source. The monolayer
h-BN film was obtained over the whole Pt foil (2 5 cm2) under <100 mTorr, where the size is limited only by the Pt foil size. A borazine source was
catalytically decomposed on the Pt surface, leading to the self-limiting growth of the monolayer without the associating precipitation, which is very similar
to the growth of graphene on Cu. The orientation of the h-BN domains was largely confined by the Pt domain, which is confirmed by polarizing optical
microscopy (POM) assisted by the nematic liquid crystal (LC) film. The total pressure and orientation of the Pt lattice plane are crucial parameters for
thickness control. At high pressure (∼0.5 Torr), thick film was grown on Pt (111), and in contrast, thin film was grown on Pt (001). Our advances in
monolayer h-BN growth will play an important role to further develop a high quality h-BN film that can be used for vertical tunneling, optoelectronic
devices and growth templates for a variety of heterostructures.