Phase formation and stability of N+ implanted SiC thin films

Abstract

Silicon carbide amorphous thin films have been bombarded with 100 keV N ions. Infrared-absorption spectroscopy has been used to study the effect of increasing ion doses, up to 5×10¹⁷ N⁺ cm⁻², on the evolution of chemical bonding between Si, C, and N. The changes induced by thermal annealing at different temperatures, up to 973 K, on the stability of the bombardment induced SiC_xN_y phase are investigated, together with the effect of surface oxidation during the postannealing cooling of the films. The new phase is thermally stable within the temperature range investigated. At the highest implantation dose a threshold is reached above which N atoms are located as interstitial, or are weakly bonded in the host film. Annealing at high enough temperature induces migration toward the surface and subsequent loss of interstitial N.