Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
703349 | Diamond and Related Materials | 2006 | 5 Pages |
In this work, scanning tunnelling microscopy (STM) and scanning tunnelling spectroscopy (STS) were applied to investigate the surface morphology and the surface electronic structure of plasma-treated (100)-oriented CVD diamond films. These films were hydrogenated using a conventional MWPE-CVD (microwave plasma enhanced chemical vapour deposition) reactor containing a H2 or a H2 / O2 mixture. A comparison is made between (100)-oriented CVD diamond films hydrogenated with and without a small addition of oxygen (1%). X-ray Photoelectron Spectroscopy (XPS) and UV Photoelectron Spectroscopy (UPS) measurements point to the presence of O-atoms at the (sub)-surface of the diamond film. The measured conductivity is significantly different for the two processes of hydrogenation. Annealing experiments point out that the samples, which were terminated using the H2 / O2 mixture are still conductive enough after annealing at 410 °C to enable STM experiments. Here, we discuss the mechanism for STM imaging of H2 / O2 treated diamond films, associated with surface states induced by the oxygen incorporation.