Low-Temperature Synthesis of Large-Area Hexagonal Boron Nitride Films on Diverse Substrates by Plasma Afterglow Deposition

In recent years, the discovery of an ever-increasing list of properties has led to a much broader range of potential applications, including quantum photonics, memristive devices, and extreme-environment coatings. However, current growth methods for hBN films are characterized by a narrow selection of substrates and high temperatures that require transfer and limit scale-up.

Here, we report a remote plasma-activated approach to directly synthesize large-area hBN films on a diverse range of representative metallic, semiconducting, and amorphous insulating substrates. Specifically, we employ the spatial afterglow of an Ar/H₂ plasma to activate ammonia borane, which enables the growth of thick (>30 nm), uniform, and stoichiometric films on substrates such as Si, SiO₂, glass, fused silica, Mo, and Al.