Cost Effective Growth of Silicon Mono Ingots by the Application of a Mobile Recharge System in CZ-Puller

The permanent demand on the improvement of solar cell efficiency and reduction of production costs has placed much focus on the multiple Cz-crystal pulling technique from one crucible. The use of lower quality silicon as feedstock for monocrystalline material is not an alternative track because it is in contradiction to the quest for high cell efficiencies. PVA Crystal Growing Systems Gmbh has developed a novel mobile recharge system for Czochralski pullers, the SiCharger MRS. This systems is capable of handling silicon feedstock material up to a chip size of 15 mm and was extensively tested under industrial conditions. The assignment for a chip size of 40 mm is currently under series of tests, the results are promising. One MRS-system can serve several pullers, presuming a suitable production organization. Investment cost and thus amortization period are minimized. In this paper the MRS-system is presented in detail as well as its operation during the recharging of the hot crucible. The influence of the different types of feedstock on the recharge process is presented. The segregation effect of impurities on the quality of multiple ingots grown in one crucible is shown.