Height control system and method for crucible high-temperature line and growth furnace

Abstract

The invention provides a height control system and method for a crucible high-temperature line and a growth furnace. The system comprises a temperature acquisition unit, a control unit and an execution unit, wherein the temperature acquisition unit is used for acquiring actual temperatures corresponding to different heights of a crucible and sending the actual temperatures to the control unit; thecontrol unit is used for obtaining the actual height value of the crucible high-temperature line based on the actual temperatures corresponding to different heights of the crucible, and comparing theactual height value with the preset position height value of the crucible high-temperature line; and the execution unit enables the crucible and an induction coil surrounding the crucible to performrelative lifting motion according to the comparison result of the control unit, so that the actual height value is consistent with the preset position height value. According to the height control system for the crucible high-temperature line, the accurate position of the crucible high-temperature line can be obtained in real time, meanwhile, closed-loop control over the position of the crucible high-temperature line can be achieved, and therefore the process accuracy and reliability can be improved.

Description

technical field [0001] The invention relates to the technical field of growth furnaces, in particular to a height control system and method for a crucible high-temperature line, and a growth furnace. Background technique [0002] The physical vapor transport (Physical Vapor Transport, hereinafter referred to as PVT) method is one of the mainstream methods for preparing silicon carbide crystals. like figure 1 As shown, the specific process of growing SiC single crystal by PVT method is as follows: usually SiC crystal 1 is placed on the top of graphite crucible 2 as a seed crystal, SiC powder 3 is placed on the bottom of graphite crucible 2 as a material source, and induction coil 4 places graphite crucible 2 Induction heating, the internal temperature of the crucible reaches about 2300°C, so as to realize crystal growth. In addition, cooling water is introduced into the gap between the outer quartz tube 5 and the inner quartz tube 6 to play a cooling role. During the cryst...

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Problems solved by technology

[0004] However, due to the lack of real-time monitoring data during the crystal growth process, the existing technology completely relies on theoretical values ​​to estimate and adjust the height of the crucible high-temperature line 8, which is open-loop control. This control method has poor accuracy and low precision. Control of the entire process parameters

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