Dimers as Fast Diffusing Species for the Aggregation of Oxygen in Boron-Doped Czochralski Silicon: Formation of New Thermal Donors

摘要

The thermal behaviors of oxygen-related complexes in boron doped Czochralski Silicon (Cz-Si) wafers at 450°C and 800°C were investigated using Fourier transform infrared spectroscopy (FTIR) and Hall mobility measurements. Activation of thermal donors (TDs) at 450°C leads to a decrease of both mobility and majority carrier concentration using the four point probes configuration of Van Der Pauw. It was found that annealing at 450°C would possibly affect the electronic properties of the Si wafers via the formation of interstitial dioxygen defects (IO2i), which exhibit an IR absorption band positioned at 545 cm–1. A strengthening of the IR bands peaking at around 1595 cm–1, 1667 cm–1, 1720 cm–1 and 1765 cm–1 occurs at 450°C, while they disappear at 800°C. At high temperatures, the precipitation of interstitial oxygen becomes predominant over all other oxygen-related reactions. The dynamic of oxygen-thermal donor generation-annihilation in Cz-Si involving the formation of small oxygen clusters is discussed.