EPR of defects in semiconductors: Past, present, future

Important physical concepts learned from early EPR studies of defects in si licon are reviewed. Highlighted are the studies of shallow effective-mass-l ike donors and acceptors by Feher, of deep transition-element impurities by Ludwig and Woodbury, and of vacancies and interstitials by Watkins et al. It is shown that the concepts learned in silicon translate remarkably well to corresponding defects in the other elemental and compound semiconductors . The introduction of sensitive optical and electrical detection methods du ring the intervening years, and the recent progress in single-defect detect ion insure the continued vital role of EPR in the future. (C) 1999 American Institute of Physics. [S1063-7834(99)01705-0].