CPC C30B 29/06 (2013.01) [C30B 15/20 (2013.01); C30B 15/36 (2013.01)] | 10 Claims |
1. A monocrystal growth method, comprising:
loading silicon material into a crucible for melting to form molten silicon;
lowering a heat shield to a preset position, wherein a first preset distance is formed between a lower edge of the heat shield and a liquid level of the molten silicon, the position of the lower edge of the heat shield is used as calibration, wherein the first preset distance is in a range of 30 mm to 50 mm;
in a first stage, using a counterweight to hang a seed shaft to gradually descend in a first direction, using a camera to acquire a pixel image of the seed shaft and the lower edge of the heat shield, and using an image processing apparatus to fit a reference circle according to the pixel image of the lower edge of the heat shield, wherein the reference circle has a reference line extending along a second direction, a center of the reference circle falls on the reference line, and when the seed shaft descends, the pixel image of the seed shaft gradually approaches the reference line;
wherein when a bottom edge of the pixel image of the seed shaft intersects with the reference line, a bottom surface of the seed shaft is flush with the lower edge of the heat shield in a horizontal plane, then a second stage is entered, in which the image processing apparatus records a current position of the seed shaft, the seed shaft is continuously lowered by a fixed height, and a seed located at a bottom end of the seed shaft extends into the molten silicon for monocrystal growth;
performing seeding process;
performing shouldering process;
performing body growth; and
tailing.
|