Monitoring ion-assisted boron nitride deposition process - by substrate current measurement to determine content, thickness and deposition start of cubic boron nitride.

: Bewilogua, K.; Schuetze, A.

Abstract
A method of determining the cubic boron nitride content in boron nitride layers formed by ion-assisted deposition on substrates biased with a defined voltage involves measuring the current and calculating the cubic boron nitride content from the measured current strength after a significant current increase. USE - Eg. in the CVD or PVD (eg. sputter deposition) of cubic boron nitride coatings for tools or heavy duty components. ADVANTAGE - The method allows simple determination of the start of cubic boron nitride formation so that the cubic boron nitride content and thickness of the layer can be determined and the deposition process can be controlled to achieve improved adhesion and reduced internal compressive stresses. After formation of cubic boron nitride nuclei, process conditions, which reduce internal stresses, are pref. modified by variation of the substrate voltage.