Sequential ion-induced stress relaxation and growth: A way to prepare stress-relieved thick films of cubic boron nitride

It is shown that the bombardment of high quality cubic (c-) BN films with 3 00 keV Ar+ ions leads to a strong relaxation of their compressive stresses without destroying the cubic phase if the total ion fluence is kept below a n upper limit. In addition, it was found that on top of such a stress-relie ved film a further pure c-BN layer can be grown, but it builds up compressi ve stress again. Based on both results, a procedure is developed to grow th ick (> 1 mu m) c-BN films (> 80% c-BN) exhibiting low residual stress and l ong term stability under ambient conditions. (C) 2000 American Institute of Physics. [S0003-6951(00)01406-6].