Variability of metal/h-BN/metal memristors grown via chemical vapor deposition on different materials

Chemical vapor deposition (CVD) is one of the most common techniques to grow large-area hexagonal boron nitride (h-BN). However, the substrate on which the h-BN is grown plays an important role in the electrical properties of this insulating material. The high temperature used during the CVD process produces the polycrystallization of the metallic substrates, which may modify the electrical properties of the h-BN/metal from one grain to another. In this work, we compare the electrical properties of CVD-grown multilayer h-BN on three different metallic substrates: Pt, Cu and Fe. This study reveals that the properties of h-BN based devices variate remarkably from one grain to another. On the contrary, this behavior is not relevant for when using Cu and Fe. On the other hand, we have also studied the resistive switching behavior in Au/Ti/h-BN/Pt, Au/Ti/h-BN/Cu, and Au/Ag/h-BN/Fe devices, and demonstrated low variability when they are grown on the same metallic grain.