A New Method to Prevent Delamination of Diamond Films Synthesized by the Three-Step Method Using Combustion Flame

Abstract

A combustion flame method was used to synthesize diamond films on a Mo substrate. During the cooling process, most diamond films delaminated. From previous work it has been shown that a three-step method using combustion flame was viable to prevent a delamination. But it was not perfect. In order to get a better adhesion of the diamond film, distances of the flame inner cone from the substrate were changed for each step of the three-step method. The first step of the three-step method was set to the distance d=1.5mm, the second step was set to the distance d=2.0mm and the third step was set to the distance d=3.0mm, respectively, with each scratching treatment of #180, 400, 800 and 1500 on the substrate surface. The results showed that the better adhesion of the diamond film was obtained on scratched surfaces at #400, 800 and 1500. An abnormal growth of the film was able to prevent by changing the distances. The inspection by SEM and XRD showed that synthesized films on scratched surfaces at #400, 800 and 1500 by the changing distances were good diamond. It was concluded that the delamination-free diamond film could be realized by changing the distances.