SPECIAL MECHANISM OF CONDUCTION TYPE INVERSION IN PLASTICALLY DEFORMED n-Si

The aim of research is studying the mechanism of n–p inversion of the conduction type of deformed silicon crystals in the course of their thermal treatment. Initially, almost non-dislocation zone-melted phosphorus-doped n-Si single crystals with electron concentration of 2×10 14 cm –3 were studied. Uniaxial compression at temperature of 700 °С and pressure of 25 MPa increased the dislocation density to 10 8 cm –2 . After long (within 30 min) cooling of the deformed crystals to room temperature, an n–p inversion of the conduction type occurred. The effect is explained by the formation of phosphorus–divacancy complexes P V 2 in the defective atmosphere of dislocations, which are acceptor centers with energy level of E v +0.34 eV. The found out n–p inversion mechanism differs from the standard one for plastically deformed n-type semiconductors with a diamond-like crystalline structure, which consists in the formation of acceptor centers along edge dislocations.