Effects of titanium and aluminum incorporations on the structure of boron nitride thin films

Boron nitride (BN)-based composite thin films have been prepared by ion-bea m-assisted deposition (IBAD) employing two electron-beam evaporators. Appro ximately 3-5 at.% of either Ti or Al was incorporated into the BN composite films. Fourier-transform infra-rid (FTIR) spectroscopy was used for phase identification of the BN composite films. The influences of the Ti and Al a dditions on the cubic phase formation in the BN films are reported. It has been found that Al incorporation has a strong negative effect on cubic BN ( cBN) formation. No cubic phase can be obtained under the presently chosen i on-bombardment parameters. However, the disturbance of 3-5 at.% Ti addition , depending on the preparation conditions for the BN thin films, only shift s the threshold of the ion/atom ratio of the IBAD process, which is require d for cBN formation to a higher value. In order to understand the different behaviors of the Ti and Al incorporations, the chemical states of the Ti a nd Al additions hi the BN composite films were examined by X-ray photoelect ron spectroscopy (XPS), indicating preferential formation of TiB2 and AlN, respectively. (C) 1999 Elsevier Science S.A. All rights reserved.