Metastable defect in Cz-Si: Electrical properties and quantitative correlation with different impurities

The application of advanced lifetime spectroscopy on standard boron-doped Czochralski silicon (Cz-Si) revealed that the metastable defect acts as attractive Coulomb center (sigma(n)(7)=sigma(n0) T-2) which is localized in the upper band gap half at E-C-E-t = 0.41 eV and has an electron/hole capture cross section ratio k=sigma(n)/sigma(p)=9.3. While the exact electronic structure has been determined by now for the first time, the microscopic structure has still not been clarified convincingly. In order to identify the major components of the Cz-defect, the impact of different impurities on the defect concentration has been examined carefully on a wide range of different Cz-materials. The linear correlation with boron has been confirmed. Concerning the correlation with the interstitial oxygen concentration, a correlation exponent between 1.5 and 1.9 has been found. This exponent is shifted to its lower bound after an optimized high-temperature pretreatment. The strong scatter in the oxygen correlation and its dependence on the thermal pretreatment point towards an indirect impact of oxygen on the defect center. Since the vacancy concentration is known to strongly influence oxygen behavior, its impact on the metastable defect concentration is investigated.