Disturbance of oxygen by isovalent impurity atoms in silicon

Abstract

The diagram of electronic levels of A–Si–O–Si–A clusters (where A is carbon, germanium, tin or lead), has been obtained by group-theoretical analysis and molecular orbitals approaches. Three possible forms of Si substitution by isovalent impurity atoms are discussed. A linear A–Si–O–Si–A cluster and the clusters with A located in the second sphere relative to an oxygen atom with formation of a planar trans-configuration and a nonplanar cis-configuration were considered. It has been shown, that all these forms of Si substitution by isovalent impurity atoms lead to the decrease of the force constants and frequencies of local vibrations of Si–O–Si, respectively.