A temperature gradient control device and method for growing crystal materials

Abstract

The invention relates to growth equipment of crystal material, in particular to a device and a method of temperature gradient control in the growth process of the crystal material. A crucible (5) is arranged in an oven chamber (1), the lower portion of the crucible is located in a sleeve (4), and a heating element (3) is arranged outside the sleeve. A cooling medium cooling mechanism is arranged on the lower portion inside the sleeve, and the temperature gradient control with the temperature of the upper portion of the crucible high and the lower portion of the crucible low is formed by the cooling medium cooling mechanism. Due to the fact that the sleeve is sleeved outside the crucible, the heating element heats the sleeve first and then the crucible is heated by the sleeve. Due to the fact that the height of a vertical shaft at the bottom of the crucible and the bottom of the sleeve is large, and the height of the vertical shaft at the bottom of the sleeve is also large, after inert gas is injected, the heat dissipation area of the vertical shaft is increased obviously, a low-temperature area is formed between the bottom of the crucible and the bottom inside the sleeve, and a good temperature gradient is obtained. Due to the action of the sleeve, the effect that non-uniform crystal nuclei almost do not appear in the crucible can also be ensured.

Description

【Technical field】 [0001] The present invention relates to a growth equipment of crystal material, in particular the invention relates to a heating temperature gradient control device and method for growing crystal materials such as sapphire, polysilicon or single crystal silicon. 【Background technique】 [0002] During the growth process of crystal materials such as polysilicon, single crystal silicon or sapphire, in which polysilicon scraps grow into polysilicon ingots in the crucible and polysilicon is converted into single crystal silicon, the heating temperature of the crucible is controlled and the bottom of the crucible is used to Seed crystal, so that the crystal that melts and grows around the seed crystal is arranged according to the grain arrangement of the seed crystal: when the seed crystal is a single crystal, the silicon atoms of the newly grown crystal are arranged in a diamond lattice to form many crystal nuclei, and these crystals If the nuclei grow into crys...

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Problems solved by technology

[0009] The parts required for the growth of the above method include: the bottom of the crucible must be closely connected with the lower shaft to form a temperature conductor; the heat consumption of the crucible is extremely high when heating the crucible in the early stage; The heating is not uniform, so that the outer edge of the crucible is easy to form a part of the closer distance is hotter, and the temperature of the other part is cooler than that of the hotter part. In this environment, non-uniform crystal nuclei will appear.

[0010] Similarly, sapphire processing methods include pulling method, crucible lowering method, guided mode method, heat exchange method, Kyropoulos method, etc. For the current method of sapphire preparation, the above preparation methods use the rotation of the support to drive the synchronous rotation of the crucible. In the scheme, the sapphire crystallization process in the crucible is subjected to micro-shocks, which causes crystal shocks in the crystallization process and forms part of the crystal dislocation, resulting in a decline in quality

Even if the temperature gradient method is used to grow sapphire, there will be deviations in the placement angle of the crucible during the heating process, which makes the heating of the crucible uneven by the heating body, and the grown sapphire is prone to non-uniform crystal nuclei

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