Material filling method for reducing casting monocrystal seed crystal body dislocation

Abstract

The invention discloses a material filling method for reducing casting monocrystal seed crystal body dislocation. The method comprises the following steps: (1) spray coating a silicon nitride coatinglayer on the inner surface of a quartz crucible to serve as a silicon ingot release layer; (2) firstly, paving a first protection layer at the bottom of the quartz crucible; (3) then paving a monocrystal seed crystal layer on the first protection layer; (4) paving a second protection layer on a monocrystal seed crystal layer (2); (5) paving a recycling material and an original pure material at theother areas after the second protection layer is paved. According to the material filling method disclosed by the invention, the first protection layer is utilized to prevent the bottom of the monocrystal seed crystal under the high temperature and the seed crystal from being damaged by silicon nitride particles, and bottom defects are avoided; furthermore, the second protection layer is utilizedto greatly reduce effects of the gravity of an upper-layer silicon material to the seed crystal, seed crystal body dislocation is reduced, and the casting monocrystal quality is improved.

Description

technical field [0001] The invention relates to a charging method for reducing the dislocation of cast single crystal seed crystal body. Background technique [0002] At present, the method for casting single crystal in a polysilicon ingot furnace is mainly the single crystal seed crystal seeding method. The single crystal seed crystal seeding method is to first lay the single crystal silicon seed crystal on the bottom of the quartz crucible, and the single crystal silicon seed crystal layer As the target seed layer, a layer of primary fine material or polysilicon fragments is directly laid on the single crystal seed layer. This layer is a single crystal seed protection layer and can also prevent the thermal shock of the molten silicon on the single crystal seed and protect it. Lay rods or chunks on top of the layer. The traditional charging method of casting single crystal is easy to cause the main body area of ​​the seed crystal to be damaged by the sharp corner of the si...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a charging method for reducing the dislocation of the cast single crystal seed crystal body, which solves the problem that the traditional casting single crystal charging method easily causes the seed crystal body area to be affected by the sharp silicon material on the seed crystal during the high temperature melting stage. Corner compression damage, after the single crystal seed crystal body is damaged, bulk dislocations will occur in the crystal growth stage, which affects the quality of cast single crystal silicon ingots

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