Interfacial analysis of CVD diamond on copper substrates

Diamond growth on Cu substrate by means of a microwave plasma-assisted chemical vapor deposition (CVD) method has been studied. Scanning electron microscopy (SEM) photographs show that the diamond grains deposited on Cu substrate mainly appear to have triangular (111) faces in comparison with those deposited on Si substrate under the same conditions. High resolution electron microscopy (HREM) research indicates that there exists a graphite intermediate laver between CVD diamond and its Cu substrate in which a small amount of amorphous carbon is embedded. The thickness of the intermediate layer varies from a few up to several tens of nanometers, depending on the local conditions. The cracks are found in some thicker intermediate layer regions, which is considered to be one of the main factors accounting for the adhesion problem. The registry between {111} planes of some diamond particles and the beneath-graphite (0002) planes has also been evidenced by HREM. The appearance of the (111) texturing diamond film is supposed to be closely related to the graphite intermediate layer. (C) 1997 Elsevier Science S.A.