| 20100307403 | (110) DISLOCATION-FREE MONOCRYSTALLINE SILICON AND ITS PREPARATION AND THE GRAPHITE HEAT SYSTEM USED - The invention discloses (110) dislocation-free monocrystalline silicon and its preparation and the graphite heating system used. The process for preparation is as follows: clearing furnace and tidy the heat field; loading furnace; vacuumizing and argon charging; heating raw material; crystal seeding; expanding shoulder; rotating shoulder: speeding up the speed of shoulder-expanding; equal diameter: after shoulder-rotating, stabilize the crystal growth speed; finishing: turning off the power of crucible, decreasing the drawing rate manually; turning off the furnace. The graphite heating system includes: upper insulation column, lower insulation column and hearth tray arranged from the top down to form the external shell, and the peripheral surface is a stepped structure, and the thickness of the insulation layer of the upper insulation column is 20-30 mm, the thickness of the insulation layer of the lower insulation column is 60-70 mm, and the thickness of the insulation layer of the hearth tray is 70-80 mm. (110) dislocation-free monocrystalline silicon is cylinder structure, on its expanded shoulders 2 symmetrical main crest lines and 4 symmetrical sub-crest lines are formed, and 2 symmetrical main crest lines are formed on crystal cylinder surface. The present invention realizes manufacturing (110) dislocation-free monocrystalline silicon so as to meet the demand of the domestic and international markets. | 12-09-2010 |
