The effect of wet chemical etching in acid solutions on the energy spectrum of n-and p-type silicon crystals previously irradiated with high-energy electrons is studied by deep-level transient spectroscopy. It is observed that together with the well known radiation defects a number of novel deep-level centres appear near the etched surface. The depth profiles of the deep-level centres are investigated depending on the irradiation dose and the temperature of subsequent annealing. The novel centres observed are shown to be complexes of radiation defects with the hydrogen atoms which penetrated into the crystal during etching. The origin of some of these centres from the particular vacancy-related defects is established. A simple quantitative description is given of hydrogen atom penetration during the etching and formation of the hydrogen-radiation defect complexes. Based on this analysis, the radius of hydrogen capture to the well known A-centre (vacancy-oxygen complex) is estimated and the centre with an energy level of E c − 0.32 eV is identified as a complex of the A-centre with two hydrogen atoms.

Electron beam induced current (EBIC) investigations of plastically deformed silicon in the temperature range from 90 K to 300 K were carried out. It is found that the dislocation trails left behind moving dislocations are the main defects revealed by the EBIC in crystals deformed in clean conditions. With an increase of the contamination level, the dislocation contrast in p-type samples increases. It is observed that the EBIC contrasts of both dislocations and dislocation trails increase with cooling in p-type silicon, while in n-type samples the EBIC contrasts exhibit the opposite trends for both defects.

It is shown that after plastic deformation in clean conditions the most efficient recombination defects in Si are dislocation trails. The DLTS spectrum associated with the defects in the dislocation trails in p‐Si are revealed. The thermal annealing effect on the electrical properties of these extended defects has been studied. A complex annealing kinetics of defects in the dislocation trails is revealed by the EBIC and DLTS. It is shown that annealing at 800 °C essentially decreases the EBIC contrast of dislocation trails. The DLTS spectrum associated with dislocation trails is also found to disappear after such annealing. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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