| Summary: | 碩士 === 中華科技大學 === 電子工程研究所碩士班 === 101 === Abstract
We use the COMSOL Mutiphysics computer software simulation to study the reference parameters of the crystal growth of silicon carbide (SiC) by the physical vapor transport method (referred to as: PVT method).
The conditions that affect the growth of SiC are the temperature setting, the temperature gradient, the distance between the seed crystal and the powder material. From the first stage of the study, if we assumed the frequency and current of the induction in the case is 120Hz, 1000A, the temperature we simulated in a cavity is about 1,400 to 2200℃. The optimum position of the center of the RF coil is located on the position of the powder material. The maximum axial temperature gradient and the smallest radial temperature gradient can be obtained on this location with respect to the other position. From the second stage of the study, we can see from the simulation results, if we increase the distance between the pitch of the coil, the system heating efficiency will be reduced, this will cause a decline in the growth temperature of the cavity, the axial temperature gradient is also reduced; while lower growth temperature or the smaller the axial temperature gradient, the growth rate of the crystal will be directly reduced, but the radial temperature gradient becomes smaller, while the reduction of the radial temperature gradient of the growth surface will reduce the thermal stress on the surface, also can reduce the generation of microtubule, dislocations, and other structural defects, and to obtain a good quality of single crystals. On the other hand, narrow the distance between the pitch of the coil, the axial temperature gradient increases, the growth rate of the crystal becomes large, but the radial temperature gradient of the growth surface becomes larger, thereby affecting the quality of the growth of single crystals.
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