Characterization of semiconductor interfaces by second-harmonic generation

In recent years, optical second-harmonic generation has matured into a vers atile and powerful technique for probing the electronic and structural prop erties of buried solid-solid interfaces. In particular Si/SiO2 interfaces h ave been studied extensively and significant progress has been made in unde rstanding the sensitivity of second-harmonic generation to interface defect s, steps, strain, roughness, electric fields, carrier dynamics, and chemica l modifications. The macroscopic and microscopic aspects of the second-orde r nonlinear optical effects at buried semiconductor interfaces have been tr eated theoretically by first-principles calculations and semi-empirical mod els. It is the aim of this review article to present a comprehensive overvi ew of recent accomplishments, current understandings and future directions in this field. (C) 1999 Published by Elsevier Science B.V. All rights reser ved.