Single crystal growth device and method

Abstract

The invention provides a single crystal growth device and a method. The temperature gradient in the crucible can be accurately and actively controlled, and by strengthening the structure of the vacuum chamber, the deformation after the long-time use can be prevented, and therefore the residual stress of the single crystal in the length direction during the single crystal growth can be reduced to the greatest extent, the cracks or the breaking can be prevented, and the single crystal growth diameter can be increased. The single crystal growth device comprises a crucible 30 capable of moving upwardly and downwardly in a chamber 10, a side part heating device 22 disposed on the side of the crucible 30, a lower heater 24 disposed on the lower part of the crucible 30, a cooling rod 40 capable of penetrating the chamber10 and the lower heater 24 to reach the crucible 30, and capable of moving upwardly and downwardly, a driving unit 50 used for driving the cooling rod 40, and a power distribution device capable of controlling the heating conditions of the side heater 22 and the lower heater 24, and the up-down moving condition of the cooling rod 40.

Description

technical field [0001] The present invention relates to a single crystal growth device and a crystal growth method, in particular to stably controlling the internal temperature gradient of a crucible, and minimizing the residual stress in the length direction of the sapphire single crystal by using a heat exchange method to prevent cracks or ruptures. A single crystal growth device and a crystal growth method for making the single crystal grow larger and increasing the growth rate in the length direction of the single crystal. Background technique [0002] With the rapid development of electronic technology, the demand for sapphire single crystal with excellent optical and physical properties in the display field has increased rapidly. Sapphire single crystal, which is mainly composed of alumina single crystal, has excellent light transmission and heat dissipation. It is the core material of rear projection TV or LCD module substrate that requires high requirements on these ...

AI Technical Summary

Problems solved by technology

[0015] Therefore, the larger the sapphire single crystal grows, the farther the distance between its solid-liquid interface (solid-liquid interface) will be. It is not easy to control the temperature gradient, and cracks or cracks caused by thermal stress are prone to occur. There is a limit to the size of sapphire growth.

[0016] In addition, the temperature gradient of the sapphire melt is only formed by the heater 115 and the seed crystal 130. The more the single crystal grows upward, the farther the solid-liquid interface is away from the seed crystal. It is difficult to control the temperature gradient in the parallel and vertical directions of the single crystal length, resulting in Cracks and cracks are prone to occur, and the growth rate of single crystals will be reduced

[0017] In the prior art, while the crucible 112 is heated by the heater 115, the temperature gradient of the crucible 112 is controlled by the guard plate 113, which has limitations in temperature gradient control, resulting in cracks or cracks easily occurring during the single crystal growth process

Moreover, as the sapphire single crystal growth process is repeated, the thermal hysteresis (Thermal Hysteresis) phenomenon accompanying the high temperature environment of the single crystal growth furnace 110 causes deformation of the vacuum chamber 111, and this deformation cannot maintain a certain temperature for a long time. The internal temperature of the crystal furnace 110, in order to provide the optimum temperature required for the growth of sapphire single crystal, each cycle is controlled differently, it is difficult to maintain the quality stability of the product

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