Deposition and Characterization of Boron Nitride Coatings Produced by magnetron sputtering

Abstract

Boron nitride (BN) is an important technological material with thermal, electrical, and mechanical properties that approach those of diamond. BN may be formed in three main crystalline forms: cubic (c-BN), wurtzite (w-BN), and hexagonal (h-BN). c-BN is the most attractive BN structure due to an unique set of properties. Three factors are common to all successful PVD c-BN experiments: bombardment of the growing film by energetic ions (generally 100-500 eV). an elevated substrate temperature (300-400 °C optimum), and the achievement of the correct film stoichiometry. In this work the literature was reviewed on the physical vapour deposition and characterization of c-BN thin films, placing special emphasis on the substrate bias (d.c. or r.f.) as a dominant effect on the c-BN content onto films. BN thin films were prepared using d.c and r.f. negative substrate bias. Threshold bias for formation of c-BN phase was identified for both cases. Films were characterized by Fourier Transformed Infrared Spectroscopy (FTIR) used for phase identification. Atomic Force Microscope (AFM) and Scaning Electronic Microscope (SEM) for morphological structural characterization. Characterization of thin films obtained is according to layer structural models proposed in the literature.