The growth and characterization of boron nitride coatings

Deposition parameters greatly affect the phase, microstructure, and chemical bonding of boron nitride coatings grown by ion-assisted PVD processes. BN coatings which have been grown by an ion-assisted pulsed laser deposition process have been examined by many characterization techniques, including infrared absorption, Auger electron spectroscopy, NEXAFS, and transmission electron microscopy. Elemental bonding and the crystallinity of BN coatings grown in three nitrogen ion energy regimes: high (2500 eV), low (700 eV), and without ions (0 eV) are examined, and the results interpreted within the framework of a compressive stress mechanism for cBN film growth. In addition, recent results are reported in which postdeposition ion implantation into sp(2)-bonded BN coatings which are under compression, is found to produce an amorphous, sp(3)-bonded BN phase.