Nanoscopic investigations of diamond properties by scanning probe microscopy techniques

In order to improve the quality of artificially produced diamond, a thorough analysis of the realised specimens is mandatory. Recognition of defects and their subsequent characterisation has to be carried out on a nanoscopic level to ensure that even smallest structures with modified material properties can be evaluated. Especially thermal/mechanical, optical/opto-electronic, as well as electrical/electronic properties have to be characterised, since these properties are responsible for the significance of diamond for a vast variety of applications. In this work we would like to present the efficiency of scanning thermal microscopy and scanning near-field acoustical microscopy to determine the thermal conductivity as well as the mechanical properties with a resolution in the nanometre scale. To determine electrical/electronic properties of chemical vapour deposition (CVD) diamond, a scanning force and scanning electron microscope (SEM) hybrid system was used. Finally, cathodoluminescence investigations as a well established and nondestructive method for analysing impurities and defects in natural and CVD diamond were carried out in a scanning near-field optical microscope/SEM hybrid system. Using these techniques, nanoscopic distributions of defects within small diamond grains became visible without any sample preparation. (C) 1999 Elsevier Science S.A. All rights reserved.