Conditions for Formation of BN Film by Ion Plating Method

Abstract

An investigation was carried out to synthesize cBN film on a Si wafer by means of a reactive ion plating process assisted hot cathode plasma discharged within a parallel magnetic field. The BN films prepared under various depositing conditions were analyzed by IR spectroscopy and microprobe chemical state analysis. It was found that the deposited BN films were composed of cBN and hBN, and the cBN content in the film ranged from 0% to a maximum of 82%. The cBN content was dependent on the ionization electrode current, RF power applied to a substrate and EB power(evaporation rate of Boron), and increased with increasing values of their parameters. But the BN film could not be deposited under excessive RF power because of sputtering predominantly caused by ions impinging on a substrate.
The cBN content was increased remarkably by introducing Ar gas with N₂ gas into the evaporation chamber. Therefore, it was assumed that thermal spikes caused by Ar ions impinging on the growing BN film play a significant role for the formation o f cBN film.