Microelectrical characterisation of diamond films: an attempt to understand the structural influence on electrical transport phenomena

The properties of microelectrical conduction in microwave plasma assisted c hemical vapour deposition (MPCVD) diamond films were investigated using an atomic force microscopy probe, giving a morphological map of the electrical conduction with a spatial resolution better than 500 nm. Also, a cathodolu minescence map with a spatial resolution of about 1 mu m was obtained, givi ng the possibility of correlating the defects involved in the different car rier transport phenomena. Using micro-Raman analysis several bands could be identified. It is found that the defects responsible for the cathodolumine scence (CL) blue band are responsible for the major part of the electrical conduction in diamond films, while the defects localised in < 111 > surface s, responsible for the green CL emission, could be involved in a less condu ctive process. (C) 2000 Elsevier Science S.A. All rights reserved.