Кластеры атомов примеси никеля и их влияние на рекомбинационные свойства кремния

Abstract

The investigation determined the types and nature of structural defects in n-type silicon featuring nickel-dopant atom clusters by using deep-level transient spectroscopy (DLTS) and measuring specific resistance, concentration and lifetime of charge carriers. The investigation employed the Solver-NEXT infrared and atomic-force microscopes. We observed that after high-temperature diffusion star-like defects appear in those Si samples that were cooled slowly. Rapid cooling of Si samples yields no decorating of dislocations, which is linked to formation of [Ni-O]-type point defects, [Ni-Si] silicides and Ni[Nis-Nii] atom pairs (unlike in the case of slowly cooled doped Si samples). The differences in shape and size of the defects forming in slowly and rapidly cooled Si samples may be explained as follows: in the case of slow cooling, as the system transitions into the equilibrium state, its free energy decreases, and nickel atoms gradually precipitating at the defects of the crystal lattice form inclusions characterised by the most energetically favourable state, that is, star-like defects. We detected an increase in charge carrier lifetime caused by formation of a trapping level connected to the [Ni-O] complex in silicon