Observation of five additional thermal donor species TD12 to TD16 and of regrowth of thermal donors at initial stages of the new oxygen donor formation in Czochralski-grown silicon

Thermal donors (TDs) are generated in Czochralski (CZ) -grown silicon by heat treatments at temperatures around 470 °C. They form a family of individual species with differing ionization energies and act as double donors (TD${\mathit{x}}^0$, TD${\mathit{x}}^{+}$). Up to 11 species are already known. We have identified five further effective-mass-like TD species termed TD12 to TD16. Subsequent annealing at 620 °C for 30 min reduces the generated TDs by at least 2 orders of magnitude. With increasing annealing time (30–180 min), an intermediate regrowth of species TD1 to TD4 is observed in parallel with the initial formation of the so-called new oxygen donors.