Behaviour of textured Ir layers exposed to the HFCVD environment of diamond

The growth of heteroepitaxied films is a great challenge for diamond microelectronics applications and iridium is one of the better substrates to achieve it. In the present study, the early stages of diamond growth on iridium have been studied by electron spectroscopy [Auger electron spectroscopy (AES), X-ray photoemission spectroscopy (XPS)]. A graphite layer is rapidly formed and its equivalent thickness was estimated from XPS data to some five to 10 monolayers. Then, the graphite layers are strongly modified by the highly reactive hydrogen radicals coming from the plasma. This induces a rehybridisation process into tetrahedral sp3 configuration which could constitute suitable sites for further diamond nucleation.