Enhanced diamond CVD synthesis on steel substrates modified by ion beam implantation and sputtering of Al

Graphite carbon preferentially forms on steel substrates during CVD diamond synthesis process, resulting in poor interface adhesion along with severe carburization-induced substrate damage. In this study, an ion implantation or a sputtering deposition of Al has been carried out to modify steel substrates to enhance diamond deposition. The Al surface modification effectively inhibited formation of intermediate graphite layer, therefore markedly enhances the adhesion of diamond films produced. For the Al-ion implanted steels, the level of substrate carburization damage is dose-dependent and improved significantly with an increasing Al implantation dose from 5 × 1016 ions/cm2 to 2 × 1017 ions/cm2. Continuous and adherent diamond films are formed on the steel substrate modified by an ion-beam sputtered Al film. The fundamental growth mechanism is discussed.