Annihilation of thermal donors in silicon annealed under high hydrostatic pressure

摘要

Annihilation of Thermal Donors (TDs) in Czochralski silicon (Cz-Si) annealed at 830 K under atmospheric pressure and treated also at 830 K but under enhanced hydrostatic pressure (HP, up to 1.2 GPa) was investigated by electrical, photoluminescence and FTIR methods. TDs were created in Cz-Si with initial interstitial oxygen concentration, c_o = 6.5 - 11.5 * 10~(17) cm~(-3) by pre-annealing at 720 K-10~5 Pa or at 720 K-HP, for up to 40 h. In comparison to the effect of annealing at 10~5 Pa, the treatment of TDs-containing Cz-Si at 830 K-1.2 GPa for 10 h resulted in the increased electron and decreased hole concentrations (in, respectively, initially n- and p-type Cz-Si), and in the decreased c_o values. Contrary to the case of Cz-Si annealed under 10~5 Pa, the treatment at 830 K-1.2 GPa resulted also in a massive creation of oxygen-containing clusters. The effect of treatment at 830 K-HP on annihilation of TDs in Cz-Si is related to the decreased rate of oxygen diffusion and creation of specific thermal donors 830 K as well as to increased concentration of nucleation centers for oxygen clustering at 830 K-HP.