Density functional theory study of the impact of tin doping on oxygen diffusion in Czochralski silicon

Abstract

The impact of tin (Sn) doping on interstitial oxygen (O i ) diffusion in Czochralski silicon is investigated by density functional theory (DFT) calculations. Two aspects are taken into consideration: (i) Sn induced lattice strain and lattice expansion; (ii) direct and vacancy-mediated interaction between Sn and O i atoms. The calculations show that the interstitial oxygen migration energy barrier increases with increasing lattice constant which grows with the concentration of Sn. Structure analysis indicates that the geometric parameters such as the bond length and the angle of Si-O-Si configuration also increase with the lattice constant, which is considered to be the origin of the increased energy barrier for oxygen diffusion. Sn-O pair formation is found to be energetically unfavorable, while the SnVO complexes have a large binding energy. Sn is however able to trap O i atoms by stimulating vacancy generation around it, which increases the oxygen diffusion energy barrier as well. It is thus predicted that oxygen diffusion in silicon with a high concentration of Sn atoms will be retarded.

IR studies of the oxygen and carbon precipitation processes in electron irradiated tin-doped silicon

“…Secondly, Sn also suppress [111] the formation of TDs. Additionally, it has been reported [60,[111][112][113][114]] the formation of SnVO complexes as well as Sn-O pairs. Remarkably, it was suggested [60] that Sn-O pairs could serve as nucleation sites for heterogeneous precipitation of O impurities in Si.…”

Oxygen aggregation kinetics, thermal donors and carbon-oxygen defect formation in silicon containing carbon and tin

“…This can be attributed to the introduction of the isovalent dopants in the lattice that impact the kinetics of the oxygen atoms and the formation of oxygen related clusters. 44,[54][55][56][57][58] Notably, it has been determined that Sn reduces the activation energy of oxygen diffusion in Si. 44 One expects that the time exponent n and the activation energy E g to exhibit opposite trends, that is, the increase of one is associated with the decrease of the other.…”

Comparative Study of Oxygen- and Carbon-Related Defects in Electron Irradiated Cz–Si Doped with Isovalent Impurities

“…Sn doping has also been used to monitor [80] the interaction between extended dislocation loops and impurities in Cz-Si. It affects the diffusion of oxygen, as well as the formation of thermal donors and oxygen precipitates in Si [39,74,[81][82][83]. Importantly, Sn alloying with Si provides materials applicable to bandgap and lattice parameter engineering, which are key elements for optoelectronic devices such as lasers and light-emitting diodes [84,85].…”