A study of indium activation in silicon using pseudopotential calculations

Using the ab initio pseudopotential planewave technique, factors limiting the activation of indium in silicon are examined. The role of Carbon in overcoming some of these issues is clarified. It is found that (1) silicon self-interstitials deactivate In by trapping them on substitutional sites; Carbon, on the other hand, traps such self-interstitials with higher binding energy and prevents them from deactivating In (2) Carbon and Indium atoms at adjacent substitutional sites are activated whereas adjacent substitutional In results in deactivation of both atoms. Only second neighbour sites of indium are activated unlike the case of Boron, where all substitutional sites remain activated.