Nitrogen Implantation Effects on the Chemical Bonding and Hardness of Boron and Boron Nitride Coatings

Abstract

February 8, 1999This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author. PREPRINT NITROGEN IMPLANTATION EFFECTS ON THE CHEMICAL BONDING AND HARDNESS OF BORON AND BORON NITRIDE COATINGSAlan Jankowski*, Thomas Felter*, Robert Patterson*, Jeffrey Hayes*, Simone Anders**, Thomas Stamler**, and David Poker*** *Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 **Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 ***Oak Ridge National Laboratory, 1 Bethel Valley Road , Oak Ridge, TN 37831 ABSTRACTBoron nitride (BN) coatings are deposited by the reactive sputtering of fully dense, boron (B) targets utilizing an argon-nitrogen (Ar-N 2 ) reactive gas mixture. Near-edge x-ray absorption fine structure analysis reveals features of chemical bonding in the B 1s photoabsorption spectrum. Hardness is measured at the film surface using nanoindentation. The BN coatings prepared at low, sputter gas pressure with substrate heating are found to have bonding characteristic of a defected hexagonal phase. The coatings are subjected to post-deposition nitrogen (N + and N 2 + ) implantation at different energies and current densities. The changes in film hardness attributed to the implantation can be correlated to changes observed in the B 1s NEXAFS spectra.