Germanium doping of Czochralski Si had attracted attention in recent years. It was pointed out that Ge doping could result in denser voids with small size, which could be eliminated easily by annealing at high temperature, and may improve the gate oxide integrity of semiconductor devices. Meanwhile, O precipitation in Czochralski Si could be enhanced by Ge, so that the internal gettering ability of wafers was improved. In addition, it was reported that Ge could suppress the formation of thermal donors. Thus, it was believed that the Ge-doped Czochralski Si could be used as the substrate of ultra-large scale integrated circuits, which had the high quality sub-surface layer, the high internal gettering ability, and the stable electrical property.

Defects in Germanium-Doped Czochralski Silicon. D.Yang: Physica Status Solidi A, 2005, 202[5], 931-8