Formation of cBN films by arc-like plasma enhanced ion plating method.

Abstract

Thin cBN films were synthesized at 350°C on various substrates such as silicon, stainless steel, TiN and WC-Co by means of an arc-like plasma-enhanced ion plating process. In this process, polycrystalline cBN films were deposited at a rate of 40 to 300 Å/min. The infrared spectra showed a strong absorption at 1050 cm-1, indicating a cubic structure of the deposited film. The electron diffraction patterns also showed a cubic structure with the lattice parameter of 3.63Å. It was inferred that the ion bombardment during the film growth plays an important role in the formation of cBN films. The cBN films deposited in this process had a high compressive stress of 4 ×1010 dyne/cm2, which is significantly greater than the value of amorphous iBN films, 1.6 × 1010 dyne/cm2. The internal stress of cBN films was greatly reduced if iBN was used as a buffer layer between cBN and substrate.