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

Abstract

Hexagonal boron nitride (hBN) nanowalls were deposited by unbalanced radio frequency sputtering system on (100)-oriented silicon, nanocrystalline diamond films, and amorphous silicon nitride (Si 3 N 4 ) membranes. The hBN nanowall structures were found to grow vertically with respect to the surface of all of the substrates. To provide further insight into the nucleation phase and possible lattice distortion of the deposited films, the structural properties of the different interfaces were characterized by transmission electron microscopy.Hexagonal boron nitride (hBN) has a structure similar to graphite, in which B and N atoms are bound alternatively in in-plane hexagonal rings forming two dimensional (2D) sheets, which are held together by van der Waals forces, forming the hBN lattice. hBN can be synthesized into nanostructured films, such as nanowalls, with tunable properties depending on the growth parameters, to make it insulating, highly compressible, or to improve its lubricity [1,5]. Grown hBN structures have so far shown a considerable number of defects and disordered BN phases, i.e. amorphous and turbostratic boron nitride (aBN and tBN), particularly at the initial stages of thin film growth. The presence of those phases is largely dependent on dynamics of chemical reactions at the substrate surface [1]. A substrate material that reduces these defective phases, creating a direct interface to the hBN phase, is therefore highly desirable.Many excellent properties of diamond, such as a negative electron affinity on hydrogen terminated surfaces, mechanical hardness, chemical inertness, and good thermal conductivity

Structure, Properties and Applications of Two‐Dimensional Hexagonal Boron Nitride

“…Between the AlN template substrates and Fe catalytic layers, h-BN films are formed with high crystalline quality, small FWHM Raman peak value, high c-axis oriented structure, and strong near-band-edge deep UV emission at room temperature. Meanwhile, Hoang et al [252] compared the h-BN nanowalls layers grown on Si substrate (100) and on nanocrystalline diamond (NCD) on Si (100) by unbalanced 13.56 MHz RF sputtering system, revealing that at the interface of diamond, the Adv. Mater.…”

“…Meanwhile, Hoang et al. [ 252 ] compared the h‐BN nanowalls layers grown on Si substrate (100) and on nanocrystalline diamond (NCD) on Si (100) by unbalanced 13.56 MHz RF sputtering system, revealing that at the interface of diamond, the hydrogen atoms help hexagonal BN phase nucleate directly and reduce disordered BN phase, thus improving the crystalline quality of h‐BN nanowalls. Wang et al.…”

Dielectric Spectroscopy of Hydrogen-Treated Hexagonal Boron Nitride Ceramics

“…Recent progress has been made through sputtering onto nanocrystalline diamond substrates, with a lower density of a-BN and t-BN, although at slow deposition rates of hundreds of nanometers per hour. 13 The hot-pressed method can produce thick h-BN ceramics using boric acid binders, with pores leading to an increased hygroscopicity. From an electronic device perspective, thicker dielectrics of h-BN are favorable to contain stray electromagnetic fields.…”

“…The resultant material may also include unwanted BN phases including amorphous and turbostratic boron nitride (a-BN and t-BN). Recent progress has been made through sputtering onto nanocrystalline diamond substrates, with a lower density of a-BN and t-BN, although at slow deposition rates of hundreds of nanometers per hour . The hot-pressed method can produce thick h-BN ceramics using boric acid binders, with pores leading to an increased hygroscopicity.…”

“…This approach introduces porosity leading to an increased hygroscopicity. Recent progress has been made through radio frequency sputtering of thin films onto nanocrystalline diamond substrates, producing a lower density of a-BN and t-BN and preferential growth of h-BN, although deposition rates are slow at hundreds of nanometres per hour 10 . From a device perspective, thicker layers are favourable to contain or attenuate stray electromagnetic fields for a) Electronic mail: cuencaj@cardiff.ac.uk dielectric encapsulation or absorber applications, respectively.…”