Gradient Interface Layers to Improve c-BN Thin Film Adhesion

摘要

The poor adhesion commonly observed for c-BN thin films is caused by the high compressive stress of the films, and the low adhesion strength at the interface. A close examination of the special nature of the c-BN/substrate interface shows that the textured h-BN nucleation layer is mechanically the weakest link of the system and should thus be avoided. Further measures to increase the adhesion strength are a rough interface, and interfacial adhesion layers. First experiments to deposit a graded interface layer (B → BN) result in extremly rough interfaces, a reduced nucleation layer thickness, and a drastically improved adhesion.