Electron microscopy of natural and epitaxial diamond

Abstract

Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. Ultimately, it is preferable to use low-defect-density single crystal diamond for device fabrication. We have previously investigated polycrystalline diamond films with transmission electron microscopy (TEM) and scanning electron microscopy (SEM)e.g.1 and homoepitaxial films with SEM-based techniquese.g.2. This contribution describes some of our most recent observations of the microstructure of natural diamond single crystals and homoepitaxial diamond thin films using TEM.We are developing techniques to thin diamonds to electron transparency in the region of interest; particularly as diamond is difficult to mechanically thin. One simple (but time consuming) approach for the fabrication of plan-view diamond TEM samples is to thin only by ion milling. Figs. 1 and 2 show TEM micrographs taken from a (100) natural type IIb (semiconducting) diamond crystal and a (100) natural type la diamond that have been ion milled to electron transparency.