Adhesion of CVD diamond films on silicon substrates of different crystallographic orientations

In order to gain insight into the adhesion mechanisms of diamond films, we examine Si substrates with three different crystallographic orientations at the various stages of the deposition process. This allows one to distinguish the surface phenomena involved in diamond deposition from those due to gaseous plasma processes. We find that the initial ultrasonic scratching treatment produces partial graphitization of the diamond powder, and it controls the crystallite size through the carbon residues. On the other hand, an increased surface roughness due to H-atom etching correlates with increased adhesion. The deposited film adhesion is found to increase in the sequence Si(111)