Analysis of the biaxial strain state of Al-doped c-BN films using diffraction experiments with synchrotron radiation

Thin films of cubic-boron nitride with a small amount of aluminum were produced by rf magnetron sputtering of a h-BN target and an additional Al ring-shaped electrode. Then the strain state of the biaxially stressed films was measured using synchrotron X-ray diffraction and the lattice spacing that unstressed films would have was calculated for different amounts of aluminum. This unstressed lattice spacing gets larger with increasing Al-amount. There is much evidence that the aluminum atoms are substitutionally incorporated at boron sites. This article provides an insight into the method of determining the unstressed lattice spacing using a slightly changed sin(2) Psi method. (C) 2003 Elsevier Science Ltd. All rights reserved.