Electrical properties of silicon, heat-treated at 530 °C with subsequent electron bombardment

Abstract

The effect of heat treatment at 530 °C and electron bombardment on the electrical parameters of silicon single crystals has been investigated by DLTS and by the Hall effect. The temperature 530 °C was found to correspond to the minimum efficiency of generation of oxygen-related thermal donors (OTD) in the temperature interval 500–600 °C. It is shown that thermal defects created at 530 °C (OTD-530) do not influence the formation of the main types of secondary radiation defects upon subsequent electron bombardment. It is found that the spectrum of OTD-530 levels is complex and that it depends on the duration of the heat treatment. The main characteristics of these levels were determined. An abnormally small cross section for capture of the electrons by the OTD-530 donors and the absence of any interaction between the OTD’s and the primary radiation defects are explained in terms of screening of their interaction with the mobile charges as a result of the nonuniform spatial distribution of the OTD’s. The local OTD concentration in the microinhomogeneities is estimated to lie in the range 10¹⁷–10¹⁹ cm⁻³.