Scalable Synthesis of Uniform Few-Layer Hexagonal Boron Nitride Dielectric Films

Abstract

Two-dimensional or ultrathin layered materials are attracting broad interest in both fundamental science and applications. While exfoliation can provide high-quality single- and few-layer flakes with nanometer to micrometer size, the development of wafer-scale synthesis methods is important for realizing the full potential of ultrathin layered materials. Here we demonstrate the growth of high quality few-layer boron nitride (BN) films with controlled thickness by magnetron sputtering of B in N(2)/Ar, a scalable process using only benign, nontoxic reagents. BN films up to two atomic layers are synthesized by reactive deposition at high substrate temperatures. Thicker monocrystalline BN films with an arbitrary number of atomic layers are achieved in a two-step process comprising cycles of alternating room temperature deposition and annealing. Tunneling transport across these BN films shows pinhole-free insulating behavior on μm(2) scales, demonstrating the realization of high quality ultrathin dielectrics.

Layer-by-Layer Dielectric Breakdown of Hexagonal Boron Nitride

“…Although other growth techniques are available, 18,[26][27][28] their quality still requires improvement. The BN was transferred to a silicon wafer coated with a 50-nm layer of platinum using the mechanical exfoliation technique.…”

Initial stages of growth and the influence of temperature during chemical vapor deposition of sp2-BN films

“…However, it is possible to distinguish between them by observing the stacking sequence of the basal planes in atomic resolution TEM or by performing XRD measurements of diffraction peaks characteristic of the h-BN and r-BN phases. As a consequence, there are reports showing the formation of h-BN and r-BN when different growth conditions are employed 23,30 . In addition, to these two crystalline forms of sp 2 -BN, two less ordered forms exist:…”

On the use of two dimensional hexagonal boron nitride as dielectric

“…Within PVD family, magnetron sputtering has been the most widely used P. Sutter et al [68] successfully synthesized monocrystalline and high-quality wafer-scale boron nitride films by magnetron sputtering technique on a 100 nm Ru / α-Al 2 O 3 substrate. During the preparation, a A C C E P T E D M A N U S C R I P T…”