Prospects of direct growth boron nitride films as substrates for graphene electronics

Abstract

We present a route for direct growth of boron nitride via a polyborazylene to h-BN conversion process. This two-step growth process ultimately leads to a >25x reduction in the RMS surface roughness of h-BN films when compared to a high temperature growth on Al 2 O 3 (0001) and Si (111) substrates. Additionally, the stoichiometry is shown to be highly dependent on the initial polyborazylene deposition temperature.Importantly, CVD graphene transferred to direct-grown boron nitride films on Al 2 O 3 at 400°C results in a >1.5x and >2.5x improvement in mobility compared to CVD graphene transferred to Al 2 O 3 and SiO 2 substrates, respectively, which is attributed to the combined reduction of remote charged impurity scattering and surface roughness scattering. Simulation of mobility versus carrier concentration confirms the importance of limiting the introduction of charged impurities in the h-BN film and highlights the importance of these results in producing optimized h-BN substrates for high performance graphene and TMD devices.

Three-dimensional foam-like hexagonal boron nitride nanomaterials via atmospheric pressure chemical vapor deposition

“…Quantitative analysis of the EDS data to obtain stoichiometry indicated samples to be boron-rich. Upon review of the available literature, it was found that with synthetic h-BN it is not uncommon to observe a boron-rich stoichiometry, especially when polyborazylene is one of the dominant chemical species facilitating h-BN growth [25][26][27]. However, it is also difficult to be confident in the quantitative stoichiometry values obtained due to the known issue of light elements giving off low binding energies (188 eV for boron and 402 eV for nitrogen), thereby making it challenging to distinguish these elements from one another via an energy loss analysis and obtain an accurate determination of the B:N stoichiometric ratio.…”

Amorphous Boron Nitride: A Universal, Ultrathin Dielectric For 2D Nanoelectronics

“…In addition, the recent desire for mono-or few-layer h -BN in high speed electronic devices has proven diffi cult, as the hexagonal phase is the higher temperature phase of BN. [ 30 ] Ideally, a versatile synthesis route that facilitates nucleation and coalescence of continuous ultrathin BN insulating fi lms on all electronic materials of interest (metal, ceramics, polymers, graphene, and other 2D materials) at temperatures <200 °C, without the requirement of tuning the deposition conditions for every substrate of interest, would facilitate simple integration of ultrathin dielectrics into 2D devices. Using this method, monolayer h -BN was fi rst synthesized at high temperatures (typically > 900 °C) in isolated triangular [ 20,21 ] or hexagonal [ 22 ] domains with characteristic lengths of a few micrometers on transition metal foils including Cu, [ 22,23 ] Ni, [ 24 ] and later, others.…”

Configurable Three‐Dimensional Boron Nitride–Carbon Architecture and Its Tunable Electronic Behavior with Stable Thermal Performances

“…Bulk graphite and bulk BN are known to have very high cross‐plane thermal conductivities of around 10 Wm −1 K −1 and 30 Wm −1 K −1 , respectively. The highest cross‐plane thermal conductivity measured on 3D‐C is only 1.7 Wm −1 K −1 due to its high porosity and low density.…”