Preparation and properties of cubic boron nitride coatings

Abstract

Cubic boron nitride (CBN) has attracted a great deal of interest in recent years for its unique mechanical and optical properties. Many physical as well as chemical vapor deposition processes have been explored to synthesize CBN coatings. These techniques, however, suffer limitations owing to the requirements of high substrate temperature and/or the necessity of using toxic starting materials. We have developed a new technique where CBN films can be prepared by evaporating boric acid in NH₃ plasma. CBN films have been deposited at substrate temperatures as low as 450°C. Structure and optical and electrical characteristics of the films clearly demonstrate the simple cubic phase in the coatings. These results are presented in this paper.