Single crystal pulling furnace

Abstract

The invention discloses a single crystal pulling furnace. A furnace cover of the crystal pulling furnace is provided with at least two through holes used for containing a lifting rod, the upper portion of the lifting rod is connected with a lifting driving component, and the lower portion of the lifting rod is connected with a lifting device used for bearing a heat preservation barrel. The liftingdriving component is used for driving the lifting rod to drive the lifting device to move upwards to enable the heat preservation barrel to leave the furnace body main chamber so that accessories inthe furnace body main chamber perform direct heat exchange with the furnace wall. According to the single crystal pulling furnace provided by the invention, the heat preservation barrel can be separated from the internal accessories of the thermal field, and the internal accessories directly exchange heat with the inner wall of the furnace platform so that the cooling capacity is greatly improved,and the cooling time of the crystal pulling furnace is shortened.

Description

technical field [0001] The invention belongs to the technical field of semiconductor production equipment, in particular to a single crystal crystal pulling furnace. Background technique [0002] The main process of using a crystal pulling furnace to pull a single crystal includes furnace loading, vacuuming, leak detection, melting, welding, necking, seeding, shouldering, equal diameter, finishing, segment taking, feeding, welding, etc., as a crucible After running for a certain period of time, the furnace platform will be pulled and stopped, and the power will be reduced to zero. The furnace platform will be cooled by argon gas. Although the power will be reduced to zero during the cooling process, the heating system and the protective plate are made of graphite, and the specific heat capacity is relatively large, that is, It is said that the internal heat storage capacity is relatively large. In the same situation, the insulation barrel is made of carbon carbon, and the cr...

AI Technical Summary

Problems solved by technology

Since the heat preservation barrel cannot exchange heat with the outside world, after the crystal pulling furnace is stopped, the heat in the above objects can only be transferred through the argon medium, which leads to a slow cooling rate, and the furnace start time is generally longer than 7 hours.

[0003] With the increase of the size of the current furnace heat field, the heat storage of various internal components is getting larger and larger, and the time for cooling by argon is getting longer and longer. At present, the shutdown time of the 36-inch heat field has reached more than 10 hours, and the high temperature Furnace opening (400°C) also accelerates the oxidation rate of thermal field components and reduces the service life of thermal field accessories. At the same time, the impact of furnace shutdown on single crystal production capacity is increasing.

Images