Large silicon crystal hollow-tube growth by the edge-defined film-fed growth (EFG) method

Silicon Crystallization Technologies

“…For example, the electromagnetic casting had made significant progress; e.g., the Japanese company Sumco had shown impressive pictures of 7 m tall ingots ("taller than a giraffe"-as they claimed in their portfolio and their webpage; Kaneko, 2010;Kaneko et al, 2006;SUMCO Annual Report, 2008), but the technique was considered not cost competitive and production was stopped. There had also been many activities with respect to sheet growth (EFG -Edge-defined Film Fed Growth by Schott (Mackintosha et al, 2006), String Ribbon (van Glabbeek et al, 2008 by Evergreen/Sovello, to mention just the most prominent ones), but so far, none of them had really been able to reach the cost structure and/or the quality of Cz and VGF. We will therefore focus in the following on the predominant and most promising PV silicon bulk crystallization technologies.…”

3D coupled electromagnetic and thermal modelling of EFG silicon tube growth

“…For electromagnetic simulation the eight-fold symmetry of the EFG system allows confining our FE-geometry to 1 16 part. The electromagnetic system includes all electrically conductive parts of the EFG set-up, two induction coils with magnetic flux concentrators (see Fig.…”

“…during blocking of ingots or sawing of wafers. Many efforts were successfully done in the past to improve the surface quality, to further reduce the tube thickness, and to increase the yield [1]. A special characteristic of EFG ribbon growth is the very high temperature gradient at the melt-crystal interface, which is necessary to dissipate the latent heat.…”

Characterization of bismuth germanate crystals grown by EFG method

“…The length of EFG grown crystals may exceed 1 m [4] providing the high production yield. Higher growth rates are inherent in EFG method compared to those in CZ due to stable position and shape of crystallization interface at growth from thin layer of melt.…”