Structural and electrical studies of selenium and silicon ion implanted gallium arsenide

The thesis concerns the structural and electrical properties of selenium and silicon ion implanted gallium arsenide. The transmission electron microscope was employed in the structural studies, whereas the electrical work involved carrier concentration and mobility profiles after annealing. The structural results for the Se implanted layers revealed both precipitate particles and dislocation loops after annealing, whereas only dislocation loops were present in the Si implanted layers. Models were proposed for the formation of damage and electrical activation in implanted Se, and in implanted Si. The importance of dislocations as electron scatterers in a number of Se and Si implanted layers was also discussed. (U.K.)