ABSTRACT
Department ofMaterials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ, UK
ABSTRACT: Some recent advances in instrumentation for electron microscopy and microanalysis are reviewed. Results are presented for dopant imaging using secondary electron contrast in a scanning electron microscopy for Si, GaAs and GaN. It is shown that dopant levels as low as 5xl014 cm-3 can be revealed using this technique. A variety of analytical TEM methods have been used to study a Til AI contact on GaN and the structural nature of this ohmic contact is revealed, in particular the presence of a TiN layer only 1.5 nm thick at the metal-semiconductor interface. EELS has been used to study individual defects in GaN, and it has been shown that a stacking fault known as DB 1 has a state in the bandgap and is charged, whereas another fault, DB2, does not have a state in the bandgap and is uncharged.
