Uniformity of multilayer hexagonal boron nitride dielectric stacks grown by chemical vapor deposition on platinum and copper substrates

Large-area multilayer hexagonal boron nitride (h-BN) dielectric stacks can be grown on different metallic substrates by chemical vapor deposition (CVD). The high temperatures used during the growth produce the polycrystallization of the metallic substrates (leading to different crystallographic orientations at the surface of each grain), which may influence the catalytic activity of the CVD process on different grains, as well as the properties of the h-BN stacks grown on them. In this work we compare the uniformity of multilayer h-BN dielectric stacks grown via CVD on two different metallic substrates: Pt and Cu. Our study reveals that using Pt substrates leads to h-BN thickness fluctuations from one Pt grain to another, while this effect remarkably reduced when the h-BN is grown on Cu substrates. Therefore, the use of Cu substrates seems to be more convenient for h-BN production and integration at the wafer level.