Annealing Properties of Defects in Ion-Implanted 3C-SiC Studied Using Monoenergetic Positron Beams

Abstract

Annealing properties of defects in N2+- or Al+-implanted 3C-SiC were studied using monoenergetic positron beams. For as-implanted specimens, the mean size of the open volume of defects was estimated to be close to that of divacancies. Based on the annealing behavior of the characteristic value of the S parameter corresponding to the annihilation of positrons trapped by vacancy-type defects, the temperature range for the annealing of defects was divided into five stages, and they were arbitrarily designated as I–V. Annealing behavior in stages I (20–500° C), II (500–800° C) and III (800–1000° C) was identified as the agglomeration of vacancy-type defects due to migrations of carbon vacancies, Si vacancies and vacancy complexes such as divacancies, respectively. Stages IV (1000–1200° C) and V (1200–1400° C) were assigned to be the formation of extended defects and their recovery processes, respectively. Effects of the species of the implanted ions and the substrate temperature during ion implantation on annealing properties of defects are also discussed.