SURFACE-MORPHOLOGY DETERMINATION OF LPCVD HOMOEPITAXIAL DIAMOND USING SCANNING TUNNELING AND ATOMIC FORCE MICROSCOPY

Boron-doped conducting, and nonconducting LPCVD homoepitaxial diamond films of approximately 1 and 3 mum thickness, respectively, were grown on (100) and (110) polished type IA natural diamond substrates. Initial examination of these films using LEED showed their surface structures to be compatible with the appropriate substrates. AES combined with low-energy secondary emission for primary beam energies below the K-shell energy shows the electronic structure of the films to be identical with that of the natural diamond substrates. RBS and ion channelling are unable to discriminate the substrate/epitaxial interface nor differentiate between the structural integrity of the substrate and the film. Atomic force microscopy (AFM) investigations on the substrates and the nonconducting epitaxial film surfaces after fine polishing delineate unexpected and hitherto unobserved features. Scanning tunnelling microscopy (STM) examination of the conducting film surfaces displays variable surface morphology texture not previously observed using the above techniques.