Site-selective studies of erbium ion defects in thermally grown silicon oxides

Using the site-selective technique of combined excitation emission spectroscopy (CEES), we have studied a variety of Er-doped silicon oxide layers and silicon-rich oxide (SRO) layers which contain silicon nanocrystals. With this technique we identified Er cluster defect sites which are created during thermal annealing and which dominate at high Er concentrations. We investigate the role that Si nanocrystals play in the relative abundance of these cluster sites. In attempts to reduce this clustering effect, we observed mixed results by modifying the growth procedure such that Er is already present in the silicon during oxide growth.