Defects in Ion-Implanted 3C–SiC Probed by a Monoenergetic Positron Beam

Abstract

Defects introduced by 200-keV N₂ ⁺- or Al⁺-implantation into 3C–SiC were probed by a monoenergetic positron beam. Depth profiles of the defects were determined from measurements of Doppler broadening profiles of the annihilation radiation as a function of incident positron energy. For ion implanted specimens at high substrate temperature (≥800° C), the major species of defects was identified to be vacancy clusters. The depth profile of vacancy-type defects was found to be shifted towards the surface of the specimen by implantation at high temperatures. Upon furnace annealing after the implantation, an agglomeration of vacancy-type defects was observed, and interstitial clusters were introduced below the vacancy-rich region.