Effect of Germanium Codoping on the Grown‐In Oxide Precipitates in Nitrogen‐Doped Czochralski Silicon

The effects of germanium (Ge)‐codoping at 10 18 , 10 19 , or 10 20 cm −3 level on the grown‐in oxide precipitates in 10 14 cm −3 level nitrogen (N)‐doped Czochralski (NCZ) silicon have been investigated. It is found that Ge‐codoping enhances the formation of relatively larger grown‐in oxide precipitates. However, such enhancement effect weakens with the increasing Ge‐codoping concentration. On this basis, the effect of 10 18 cm −3 level Ge‐codoping on the near‐surface denuded zone (DZ) and bulk microdefects (BMDs) associated with oxygen precipitation in NCZ silicon subjected to an anneal at 1100 °C for 4 h (1100 °C/4 h) has been paid close attention. Moreover, the sustainability of the DZ in the 1100 °C/4 h ‐annealed NCZ silicon subjected to a “copper decoration” or a rigorous oxygen precipitation anneal featuring a prolonged nucleation anneal has been addressed. Thus, it is technologically significant to learn that for the 1100 °C/4 h ‐annealed NCZ silicon, the 10 18 cm −3 level Ge‐codoping can remarkably increase the BMD density to better satisfy the requirement of internal gettering (IG) and also ensure the existence of a well‐defined DZ. Finally, the mechanism underlying the effect of Ge‐codoping on the formation of grown‐in oxide precipitates in NCZ silicon has been tentatively elucidated.