Shaped crystal growth of 50cm diameter silicon thin-walled cylinders by edge-defined film-fed growth (EFG)

Shaped Crystal Growth

“…The axial symmetry of the growing system reduces thermoplastic stress, which is the main limitation for pulling rate, and makes thin wafer growth more practical. Using this approach EFG cylindrical tubes with a diameter of 50 cm and wall thickness 75 -80 µ m have been grown up to a length of 1.2 m [Garcia 2001] . In addition, tube rotation can be used to minimize the circumferential temperature variations that make growth of EFG polygons with wall thickness less than 200 µ m diffi cult.…”

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

“…The 50 cm EFG cylinder furnace [7] can accommodate either a 12.5 cm faced dodecagon (12 sides) or a 15 cm faced decagon. A serious challenge in design of still larger diameter furnaces is the need to maintain uniform temperatures of the order of a degree across each individual face width in order to guarantee a thickness uniformity in the range 730 mm acceptable for solar cell manufacture.…”

Silicon tubes by a closed molten zone: a characterisation study

“…For instance, Garcia et al [3] developed a modified EFG process producing cylindrical tubes with 50 cm diameter, aiming at 100 mm thickness. Wallace et al [4] refer the development of post-heaters to allow the growth of string ribbon silicon with thickness below 125 mm.…”