Temperature dependent electron and hole capture cross sections of iron-contaminated boron-doped silicon

Temperature controlled photoconductance is applied to measure the electron and hole capture cross sections of interstitial iron and iron-boron pairs in crystalline silicon. The injection-dependent lifetime was measured before and after light soaking over the range 0-90 °C, and without light soaking over the range 240-320 °C. The data was then analysed to determine the electron and hole capture cross sections of the interstitial iron defect over the range 240-320 °C, and of the iron-boron defect over the range 0-90 °C. The first of these analyses involved a novel approach that independently distinguishes the capture cross sections assuming a known defect density, energy level and thermal velocity, whereas the latter involved the "characteristic cross-over point" method, which compares carrier lifetime before and after the dissociation of iron-boron pairs. This approach independently determines the temperature dependence of the capture cross sections over a wide range of temperature and identifies their capture mechanisms.