Growth and mechanical properties of BCN thin films

• Main Authors: Shih-Che Chien, 簡士哲
• Other Authors: 林舜天
• Format: Others
• Language: en_US
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/32324471217950060098

碩士 === 國立臺灣科技大學 === 機械工程系 === 89 === Boron carbon nitride (BCN) thin films were deposited on Si (100) substrates by dual-gun magnetron sputtering from graphite and h-BN targets in Ar ambient gas of a constant of 3.5 mTorr. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) were used to determine the morphology of the films and calculate the surface roughness. It was found that the incorporation of carbon atoms in boron nitride films is effective to improve the adhesion between BCN films and Si substrates. X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) analysis were performed to determine the composition of the films. The films with different carbon contents were obtained by varying RF (radio frequency, 13.65 MHz) power from the h-BN target and DC power from the graphite target. Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) studies were used to investigate the bonding states of BCN films. It was observed that B-N, B-C ,B-O ,C-C and C≣N bonds were hybrid in BCN films, and B-C bond is easy formed at low temperatures. Microstructure of BCN films was characterized by Transmission Electron Microscopy (TEM). The ternary compound films within the B-C-N composition triangle possessed a less ordered structure, and no phase separation of graphite and h-BN occurred. At high carbon content, BCN film was of uniform amorphous structure; but at low carbon content, the film has short-range order (fullerene-like) structure. Nanoindentation was employed for mechanical properties of BCN films. Hardness and elastic modulus of the BCN films were estimated 5-13 GPa and 72-155 GPa, respectively, and optimized condition in this study is at carbon content range from 25-35 at. %. The formation of B-C bond may make a contribution to the higher hardness and elastic modulus.