PREPARATION OF C-BN CONTAINING FILMS BY REACTIVE RF-SPUTTERING

Reactive r.f. sputtering by use of a hexagonal boron nitride (h-BN) ta rget has been successfully used to deposit boron nitride films. The su bstrate temperature did not exceed 300-degrees-C. It was found that th e films contained c-BN only if they were sputtered reactively in an Ar -N2 mixture at sufficiently negative self bias values. As a measure fo r the c-BN content the relative extinction coefficient Q(c) of the inf rared absorption band near 1060 cm-1 was used. The maximum of c-BN con tent could be estimated for films prepared at 3% N2 in the working gas . Furthermore Q(c) increased with increasing deposition time, indicati ng changes in the growth mechanism. Analytical studies supported the s uggestion that the films have an amorphous-like structure. Films conta ining a high content of c-BN partially delaminated quite often from th e silicon substrates. However, the lack of adhesion could not be corre lated to the internal stresses. The wear resistance of the c-BN contai ning films was clearly higher than that of h-BN deposits.