Positron Annihilation in Semiconductors

This comprehensive book reports on recent investigations of lattice imperfections in semiconductors by means of positron annihilation. It reviews positron techniques, and describes the application of these techniques to various kinds of defects, such as vacancies, impurity vacancy complexes and dislocations.The electrical and optical properties of semiconductors are dominated by lattice defects. Positron annihilation has become one of the most important techniques for the investigation of vacancy-like defects. Positrons may be captured in lattice imperfections and the annihilation signal then contains specific information on the type and the concentration of these defects. A comprehensive overview of positron studies in elemental and compound semiconductors is presented. Emphasis is put on investigations of defects in as-grown, electron-irradiated, ion-implanted, and plastically deformed material. It is shown how positrons can be used to profile structural defects in epitaxial layers and at interfaces. Possible applications of positron annihilation in defect engineering are discussed. The theoretical foundations of the interaction of positrons with matter are reviewed. The book describes in detail all important techniques of positron annihilation, such as positron lifetime spectroscopy, Doppler-broadening spectroscopy, the angular correlation of annihilation radiation, positron-beam applications, and also new methods. The sensitivity and selectivity of defect detection by positron annihilation is compared to other characterization methods.