Laying method of seed crystals, preparation method of quasi-monocrystalline silicon piece and quasi-monocrystalline silicon piece

Abstract

The invention provides a laying method of seed crystals and is used for the casting of quasi-monocrystalline silicon piece. The method comprises the steps of: seed crystals are laid on the crucible bottom, the seed crystals have a same growth surface crystal orientation of [001] or [001<->]; the seed crystals in close contact and fully cover the crucible bottom to form a seed crystal layer; the side crystal orientation of two adjacent contact the seed crystals belongs to the same crystal to the same crystal orientation family and constitute a coincidence position lattice type of grain boundary; when the side crystal orientation of the seed crystal is <110>, the crystal orientation of growth face of the adjacent seed crystals alternately splices front and back according to [001] [001<->], or one of the adjacent seed crystals rotates 90 DEG; when the side crystal orientation of the seed crystals is not <110> crystal orientation family, the crystal orientation of growth face of the adjacent seed crystals alternately splices front and back, or after the front and back alternate splicing, one of the adjacent seed crystals rotates 90 DEG. The laying of seed crystals reduces the occurrence of dislocation sources in the crystal introduction process. The invention also provides a preparation method of a quasi-monocrystalline silicon piece and the quasi-monocrystalline silicon piece.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for laying a seed crystal, a method for preparing a quasi-single crystal silicon chip and a quasi-single crystal silicon chip. Background technique [0002] At present, the casting methods of quasi-single crystal mainly include seedless seeding and seeded seeding method. The seeded seeding method is to lay the single crystal seed crystal on the bottom of the quartz crucible first, and keep the seed crystal incompletely melted during the melting stage. , the seeding growth is carried out on the single crystal seed crystal to obtain the quasi-single crystal silicon ingot. When laying the seed crystal, the growth crystal direction of the nucleation surface of the seed crystal is generally guaranteed to be consistent, but the crystal orientation of the side contact surface of the adjacent seed crystal It is usually random, and it is easy to form small-angle grain b...

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Problems solved by technology

[0002] At present, the casting methods of quasi-single crystal mainly include seedless seeding and seeded seeding method. The seeded seeding method is to lay the single crystal seed crystal on the bottom of the quartz crucible first, and keep the seed crystal incompletely melted during the melting stage. , the seeding growth is carried out on the single crystal seed crystal to obtain the quasi-single crystal silicon ingot. When laying the seed crystal, the growth crystal direction of the nucleation surface of the seed crystal is generally guaranteed to be consistent, but the crystal orientation of the side contact surface of the adjacent seed crystal It is usually random, and it is easy to form small-angle grain boundaries during the seeding growth process. The small-angle grain boundaries not only become a dislocation source during the growth process, resulting in the continuous pro

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