RECENT RESULTS IN CUBIC BORON-NITRIDE DEPOSITION IN LIGHT OF THE SPUTTER MODEL

In the field of c-BN deposition, ion-assisted processes are most commo n and best investigated. Understanding of the deposition mechanisms is the basic key to improve film quality and, therefore, to realize pote ntial applications. Recently, Reinke et al. developed a sputter model for ion-assisted c-BN deposition in which material removal processes ( sputtering and desorption) play major roles [1]. This model is used as a guideline in order to give an overview on c-BN deposition. The firs t part investigates the growth mechanisms of ion-assisted c-BN deposit ion. Therefore, a data collection which includes CVD and PVD depositio n methods was performed. The resulting dependencies are discussed in l ight of the sputter model. By comparison with other models, it is foun d that most of the experimental facts can best be described in terms o f the sputter model, whereas in the nucleation step compressive stress plays an additional role. In the second part, c-BN deposition is cons idered in a wider context. Current problems and some first approaches to overcome these problems are discussed. Furthermore boron nitride is compared with the sp(3) carbon modifications tetrahedral amorphous ca rbon (ta-C) and diamond. It is concluded that c-BN and ta-C rely on di fferent growth mechanisms; the investigation of extended parameter ran ges in the search for new ion-assisted carbon and BN modifications is proposed. Some approaches in c-BN deposition without ion assistance ar e discussed in accordance to diamond deposition. Nevertheless, the adv ances are small and no process yielding similar high-quality material as CVD diamond exists.