Device for growing high-quality crystals by PVT method

Abstract

The invention relates to a device for growing high-quality crystals through a PVT method, and belongs to the technical field of aluminum nitride or silicon carbide crystal growth. The utilization rateof raw materials is increased, the component ratio and pressure in sublimated steam of the raw materials are ensured, the difficulty in fixing and dismounting the crystal is solved, the generation ofinternal stress of the crystal is avoided, and high-quality crystals are obtained. The device comprises a crucible body, a bearing disc, a shaft, a filter plate, a crucible cover and a seed crystal support, the seed crystal support is detachably installed on the upper portion of the crucible body, the crucible cover is detachably installed on the upper portion of the seed crystal support, the filter plate is located in the crucible body, the bearing disc is installed in the crucible body in a sliding mode, and the shaft penetrates through the bearing disc to be connected with the filter plate; the crucible body comprises a growth chamber and a powder chamber, the growth chamber is located on the upper side of the powder chamber, a filter plate is installed in the growth chamber, the bearing disc is installed in the powder chamber in a sliding mode, and the upper portion of the powder chamber is in a circular truncated cone shape.

Description

technical field [0001] The invention relates to a device for growing high-quality crystals by PVT method, belonging to the technical field of aluminum nitride or silicon carbide crystal growth. Background technique [0002] In the process of aluminum nitride or silicon carbide crystal growth using the PVT method, a heater is required to heat the raw materials in the crucible body. However, during the heating process, affected by the axial temperature gradient, the raw materials near the edge of the crucible body sublime. Fast, often the raw materials in the middle cannot be used, and the steam from the sublimation of the raw materials condenses in the middle of the furnace body when it reaches the middle of the furnace body, resulting in waste of raw materials and unevenness of the sublimated steam of the raw materials reaching the seed crystal; Continuous consumption, in the later stage of growth, the composition ratio and pressure in the vapor of the raw material sublimati...

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Problems solved by technology

[0002] During the growth process of aluminum nitride or silicon carbide crystals using the PVT method, a heater is required to heat the raw materials in the crucible body. However, during the heating process, affected by the axial temperature gradient, the raw materials near the edge of the crucible body are sublimated. Fast, often the raw materials in the middle cannot be used, and the sublimated steam of the raw materials condenses in the middle of the furnace body when it reaches the middle of the furnace body, resulting in waste of raw materials and unevenness of the sublimated steam reaching the seed crystal; Continuous consumption, in the later stage of growth, the ratio and pressure of the components in the sublimated vapor of the raw materials have been seriously out of balance, so the quality of the crystals grown in this way can no longer be guaranteed; in addition, the general crystal growth is that the seed crystals are directly bonded to the bonding sheet or the crucible cover , to grow, such a structure will produce severe stress during cooling due to the difference in expansion coefficient between the bonding sheet and the seed crystal, and it is difficult to separate the crystal from the bonding sheet after the growth is completed, that is, using the cutting method to separate, the cutting process Vibrations generated in the

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