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.