Silicon material melting heating process capable of preventing silicon leakage in quartz crucible in Czochralski method

Abstract

The invention relates to the technical field of preparation of monocrystal silicon, and in particular relates to a silicon material melting heating process capable of preventing silicon leakage in a quartz crucible in a Czochralski method. The process comprises the following steps of: 1) charging, namely, charging the silicon materials into the quartz crucible; and 2) heating and melting the materials by using a heat system, namely, heating at 25 to 85 KW for 180 to 390 minutes at a quartz crucible softening and heating stage and then heating at 70 to 105 KW for 60 to 180 minutes at a silicon material heating and melting stage. The silicon material melting heating process capable of preventing silicon leakage in the quartz crucible in the Czochralski method has the beneficial effects that the quartz crucible is softened completely by gradually increasing the heating temperature and can be adhered to an external graphite crucible, so that the impact is small when the silicon materials are melted and collapsed, and the silicon leakage phenomenon caused by the fact that the unmelted silicon materials collide with the quartz crucible (particularly the cambered surface of the bottom of the quartz crucible) can be avoided.

Description

technical field [0001] The invention relates to the technical field of single crystal silicon preparation, in particular to a melting and heating process of silicon material which avoids siliconization of a Czochralski quartz crucible. Background technique [0002] In the production and preparation of Czochralski method (Cz method) single crystal, quartz crucible plays an irreplaceable role as the carrier of molten silicon. It is very important to understand the characteristics of the quartz crucible and master the correct use method to avoid the phenomenon of silicon infiltration of the quartz crucible in the process of melting silicon material. The main reasons for the silicon infiltration of the quartz crucible are: [0003] 1. Improper loading method: [0004] The contact between the material on the liquid level line and the quartz crucible is in a surface contact state, which is prone to edge hanging during the melting process and causes the crucible to deform; [000...

AI Technical Summary

Problems solved by technology

Once silicon infiltration occurs, most of the equipment in the thermal field system of the single crystal furnace will be scrapped, resulting in heavy losses

[0010] In addition, when the temperature of the melting material is low, the silicon material on the upper part of the crucible and the crucible wall are prone to "wall-hanging" phenomenon. After the silicon material in the lower part is melted, the "melting but not melting" block on the upper hanging edge will pull down the quartz crucible. And deformation occurs, resulting in silicon infiltration; and when the temperature of the melting material is too high and too fast, it will also cause the deformation of the quartz crucible during the melting process, resulting in silicon infiltration accidents.

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