Abstract
Boron nitride (BN) films have been deposited on silicon (Si) substrates with a root-mean-square surface roughness between 0.2 and 170 nm using mass-selected ion beam deposition (MSIBD). Mechanical scratching by either diamond or alumina powders with different powder sizes was used for substrate pretreatment. The effect of substrate surface roughness on the subsequent growth of BN films at different ion energies (75–500 eV) was investigated by Fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) and transmission electron microscopy (TEM). For rough substrates the surface morphology of the BN films changes from a granular structure at low ion energies to a flat and featureless surface at 500 eV ion energy. In the latter case grooves and valleys are first filled up with amorphous BN before turbostratic BN (t-BN) is formed. Eventually c-BN nucleates on the t-BN interfacial layer. The c-BN nucleation threshold energy of about 125 eV remains unchanged. Surface-like growth processes dominate at low ion energy, leading to the granular morphology. The observations are explained by ion impact on inclined micro-surfaces, leading to reduced projected ion ranges and enhanced sputtering and re-deposition into surface grooves and valleys.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.