ATOMIC CONFIGURATIONS, STABILITY, AND IMPURITY VIBRATIONS OF CARBON-OXYGEN COMPLEXES IN SILICON

We investigated the atomic configurations, stabilizing mechanism, and impurity vibrations of carbon-oxygen (C-O) complexes in crystalline si licon both theoretically (by calculating total energy using norm-conse rving pseudopotentials), and experimentally (by measuring low-temperat ure infrared absorption). We found that the second neighbor interstiti al site of a substitutional carbon atom is more stable for an oxygen a tom than the first neighbor site. Lattice relaxation is essential to t his stability. The calculations on the impurity vibrations of the C-O complex of the second-neighbor configuration closely agree with the ex perimental results. The existence of several kinds of C-O complexes wi th different configurations, which is suggested by the calculations, w as confirmed by experiment.