Preparation of B–C–N films by magnetron sputtering with different N 2/Ar flow ratio

Abstract

Amorphous B–C–N films were fabricated on silicon (100) substrates using radio frequency reactive magnetron sputtering technique with variable N 2/Ar flow ratios. The structures, chemical bonding and mechanical properties were characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and nanoindentation. We found that the N concentration is insensitive to the increment of N 2/Ar flow ratio while the B concentration decreases and C concentration increases. All B–C, C–N, and B–N bond contents increase as the N 2/Ar flow ratio varies from 1/10 to 5/10. Further improving the N 2/Ar flow ratio will promote N atoms prior to bonding with C, resulting in decreased B–C and increased C–N bond content, respectively. The changes of bond content lead to a shift of the main peaks of B1s, C1s, and N1s spectra toward higher binding energies. The hardness of B–C–N thin films is almost invariant with the N 2/Ar flow ratio.