Quantum chemical models of defects in thin silicon films

Cluster models and quantum chemical methods were used to investigate electronic structure and properties of defects in silicon, including extended defects of crystals, such as surface and inteiphases dislocations, which create regions of compression and strain. Pressure effect was simulated by reduction of the lattice constant. This appmach is adequate for investigation of thin films. Reduced influence of chemical bonding and enhanced use of free volume during O migration under high pressure have been shown. The Si and O interstitial migration activation energies were estimated as 4.21 eV and 2.73 eV, respectively, the former being indifferent to pressure.