ELECTRON-OPTICAL TECHNIQUES FOR MICROSTRUCTURAL AND COMPOSITIONAL ANALYSIS OF THIN-FILMS

Electron optical methods of determining the atomic level microstructure of thin films are discussed with reference to examples. The use of energy filtered electron diffraction and electron energy loss spectroscopy (EELS) are illustrated by using them to distinguish between amorphous carbons prepared by vacuum evaporation and the material prepared by condensing the carbon plasma stream from a vacuum arc. The latter is shown to consist almost entirely of tetrahedrally bonded carbon. These electron optical techniques are also applied to hexagonal and cubic boron nitride and to silicon and germanium carbides. Other techniques discussed are high resolution electron imaging and Kramers-Kronig analysis of EELS spectra.