Deposition of boron-nitride films by nitrogen sputtering from a boron-metal target

Abstract

This contribution deals with reactive growth of boron-nitride films by a rf nitrogen-sputtering process from a boron-metal target; thus nitrogen is functioning both as sputter and reactive gas. Only few and superficial reports of reactive sputter depositions from a metallic boron target in various argon/nitrogen mixtures exist, compared to the number of reports on rf sputtering from a BN target. Nitrogen sputtering of boron-metal has previously not been reported. It was shown by Fourier-transform infrared (FTIR) spectroscopy that the hexagonal structure of BN exclusively was deposited. Sputter rates were measured and showed no dependence on the reactive-gas flow and only a marginal dependence on sputter-gas mixtures containing 20% of krypton, argon, or helium. The reported nitrogen-sputtering process appears to be appropriate for exploration of the key parameters for phase control in BN growth and for additional surface engineering processes such as substrate bias and post-ion bombardment.

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

“…The glow discharge of the magnetron sputtering process plays two important roles in the growth of BN films (Figure a): , (i) evaporation of B by collision cascades due to the impact of energetic Ar + ions on a solid B target; and (ii) generation of nitrogen radicals via dissociation of gas phase N 2 by free electrons and ions in the plasma. On an appropriate substrate (here epitaxial Ru(0001) thin films) heated to high temperature, B and N species assemble into a well-ordered film consisting of layered atomic h-BN sheets (Figure b).…”

“…While commonly associated with polycrystalline thin films, for example, in metallurgical coatings or transparent conducting oxides, magnetron sputtering has been used to grow epitaxial metals,22,23 compounds,24 and semiconductor heterostructures,25 including high electron mobility modulation-doped quantum wells 26. Here we demonstrate the growth of high quality few-layer BN films with controlled thickness using reactive magnetron sputtering of B in N 2 /Ar, a scalable, industry-compatible process that uses only benign, nontoxic reagents.The glow discharge of the magnetron sputtering process plays two important roles in the growth of BN films (Figure1a):27,28 (i) evaporation of B by collision cascades due to the impact of energetic Ar + ions on a solid B target; and (ii) generation of nitrogen radicals via dissociation of gas phase N 2 by free electrons and ions in the plasma. On an appropriate substrate (here epitaxial Ru(0001) thin films) heated to high temperature, B and N species assemble into a well-ordered film consisting of layered atomic h-BN sheets (Figure1b).…”

Effects of Ion Beam Energy on the Formation of Cubic Boron Nitride Thin Films by Pulsed Nd:YAG Laser Deposition

“…2) Since the publication of this work, a number of processes for the formation of cBN films have been investigated using various deposition techniques, including ion plating, ion-beam-enhanced deposition, radio frequency (rf) reactive sputtering, plasma-enhanced chemical vapor deposition and pulsed laser deposition. [3][4][5][6][7][8][9] Recently, we prepared BN films by a pulsed neodymium: yttrium-aluminum-garnet (Nd:YAG) laser deposition (PLD) method. 10,11) In our experiment, BN films were deposited on Si(100) substrates using hexagonal boron nitride (hBN) targets, and an ion beam was focussed on the substrate in order to enhance the synthesis of the cBN phase.…”

Formation of thick cubic boron nitride films in noble gases

“…Kester et al reported c-BN thin films prepared using Ar, Kr, and Xe gases by ion beam assisted deposition. 6) Although the use of He was reported by Andoh et al using dual-ion vapor deposition (D-IVD) 7) and Jensen et al with radio-frequency sputtering, 8) the effects of these gases were not well-described. It is therefore necessary to understand the effects of noble gases on c-BN deposition.…”