Progress in characterization of electronic materials over the past 50 years has been illustrated by selected examples of determination of the atomistic reconstruction and formation of electronic states at surfaces and interfaces of semiconductors using surface sensitive characterization techniques. Similar techniques have been used to characterize reactions at interfaces and determine the mechanisms by which charge carrier transport is changed from that controlled by Schottky rectifying to contacts with ohmic characteristics. The use of seconday ion mass spectrometry to measure dopant profiles over dimensions <10 nm below the surface is illustrated, and the use of optical characterization techniques for real time control of semiconductor growth was also illustrated. Finally, areas of future development of characterization techniques for electronic materials were discussed. (C) 2003 American Vacuum Society.