Elucidation of the Growth Mechanism of Sputtered 2D Hexagonal Boron Nitride Nanowalls

Abstract

Hexagonal boron nitride nanowall thin films were deposited on Si(100) substrates using a Ar(51%)/N2(44%)/H2(5%) gas mixture by unbalanced radio frequency sputtering. The effects of various target-to-substrate distances, substrate temperatures, and substrate tilting angles were investigated. When the substrate is close to the target, hydrogen etching plays a significant role in the film growth, while the effect is negligible for films deposited at a farther distance. The relative quantity of defects was measured by a non-destructive infrared spectroscopy technique that characterized the hydrogen incorporation at dangling nitrogen bonds at defect sites in the deposited films. Despite the films deposited at different substrate tilting angles, the nanowalls of those films were found to consistently grow vertical to the substrate surface, independent of the tilting angle. This implies that chemical processes, rather than physical ones, govern the growth of the nanowalls. The results also reveal that the degree of nanowall crystallization is tunable by varying the growth parameters. Finally, evidence of hydrogen desorption during vacuum annealing is given based on measurements of infrared stretching (E 1u) and bending (A 2u) modes of the optical phonons, and the H–N vibration mode.

Hierarchical hexagonal boron nitride nanowall–diamond nanorod heterostructures with enhanced optoelectronic performance

“…1d). 27,28 As displayed in Fig Fig. 2c displays the confocal micro-Raman spectrum of the hBN-DNR, which is deconvoluted using the multi-peak Lorentzian fitting method.…”

“…Herein, a 3 inch-diameter pyrolytic boron nitride ceramic with material purity and mass-density of 99.99% and 1.96  10 3 kg/m 3 , respectively, was used as target. 27,28 The time for the growth of hBN nanowalls on DNRs was 30 min.…”

Engineering the interface characteristics on the enhancement of field electron emission properties of vertically aligned hexagonal boron nitride nanowalls

“…A home‐built unbalanced 13.56 MHz radio frequency (RF) sputtering system has been used for hBNNWs growth . A 3 inch‐diameter pyrolytic boron nitride (BN) ceramic target with material purity and mass‐density of 99.99% and 1.96 × 10 3 kg m −3 was utilized.…”

“…hBN is a two‐dimensional (2D) material where B and N atoms are alternatively placed in a hexagonal ring. In the lattice plane, the atoms are bound by strong covalent bonds to form 2D hBN sheets, while an interaction within different sheets is weak and governed by van der Waals forces . NEA was detected significantly on the surfaces of hBN when treated in hydrogen or oxygen plasma .…”

Direct nucleation of hexagonal boron nitride on diamond: Crystalline properties of hBN nanowalls

“…The aBN and tBN phases in particular are much more prevalent at the Si/BN interface than in the same region of the NCD/BN structure. The mixed phase of aBN and tBN extend a few tens of nanometers from the Si substrate surface before the hBN nanowall structures become more dominant [27]. The quality of the deposited BN films on the Si substrate, especially at the initial stage of thin film growth, is therefore largely dependent on many other deposition factors, i.e.…”