General stress reduction mechanisms for the deposition of cubic boron nitride thin films

Abstract

Intense ion bombardment has been necessary so far to produce cubic boron nitride thin films independent of the deposition technique used. Unfortunately, residual stress is one of the consequences of ion–surface interactions, leading to low adhesion and limited film thickness. In this study, boron nitride thin films were deposited by r.f.magnetron sputtering of a hexagonal boron nitride target combined with r.f. argon ion bombardment. The films were characterized by X-ray reflectivity analysis, X-ray Auger electron and infra-red spectroscopy as well as stress analysis. Stress reduction mechanisms are discussed: (1) deposition at higher substrate temperatures, (2) post-annealing, (3) post-ion implantation, (4) addition of a third alloying component, (5) multilayer concept, and (6) optimization of the deposition parameters.