Crystal growth furnace

Abstract

The invention provides a crystal growth furnace. The furnace comprises a chamber, a crucible and a ventilation structure, wherein the crucible is arranged in the chamber; the ventilation structure comprises a ventilation pipeline and a confluence chamber arranged in the chamber; an air inlet of the ventilation pipeline is formed in the bottom wall of the chamber; the ventilation pipeline penetrates through the bottom wall of the chamber and is communicated with the confluence chamber; and the confluence chamber is arranged below the crucible, is fixedly connected with the bottom wall of the crucible and is used for converging process gas in the ventilation pipeline to the bottom wall of the crucible. By applying the crystal growth furnace, the uniformity of the process gas participating inthe reaction is improved, so that the repeatability and the stability of a process result are improved, the real-time performance of ventilation operation can be met, and the determinacy of an equipment debugging window is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a crystal growth furnace. Background technique [0002] Currently, physical vapor transport (PVT) is one of the mainstream methods for preparing silicon carbide (SiC) crystals. To grow SiC single crystal by PVT method, SiC crystal is usually placed on the top of the crucible as a seed crystal, and SiC powder is placed on the bottom of the crucible as a material source, and then the crucible is placed in the growth furnace, and the induction coil is placed around the growth furnace. The crucible is heated by induction, and the internal temperature of the crucible reaches about 2300°C, and the growth temperature gradient is controlled, and argon gas is introduced to control the pressure in the growth furnace. During the crystal growth process, the temperature of the seed crystal is lower and the temperature of the source is higher, and there is a certain temperature gradien...

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Problems solved by technology

However, the hydrogen introduced by using this structure often cannot directly and effectively act on the SiC raw material, resulting in a decrease in the repeatability of the process results and increasing the uncertainty of the debugging window, etc.

The reasons are as follows: First, the large space in the furnace chamber will easily lead to uneven distribution of the hydrogen gas flow participating in the reaction, and the uneven gas flow will cause the amount of hydrogen reacting with the SiC raw material at different positions inside the crucible to be unstable.

Second, the furnace cavity has a large space, and there is no fixed path for the thermal movement of hydrogen, which results in a long time for hydrogen to move from the furnace cavity inlet to the outer wall of the crucible

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