Abstract
Indium phosphide (InP) single crystals, as key III-V compound semiconductor materials, play an irreplaceable role in various fields, such as optical communication and microwave millimeter-wave communication. Vertical gradient freeze (VGF) has become one of the main methods for industrial production of InP single crystals due to its advantages in temperature gradient control. However, defects such as twins and dislocations are easily generated during the production of InP single crystals by the VGF method. Through an in-depth study of the thermal field during the growth of InP single crystals, it is found that the cooling rate of the thermal field during single crystal growth is crucial and is closely related to the generation of twins, dislocations, and polycrystallization defects. Therefore, constructing a cooling model based on temperature control and the quality of InP single crystals has a positive driving effect on improving the yield of single crystal products. In this paper, by establishing a thermal field model of an InP single crystal furnace produced by the VGF method, the characteristics of temperature variation are analyzed in depth. Subsequently, numerical analysis of discrete cooling data during the cooling crystallization process is conducted, considering the quality of the InP single crystal growth. Combined with the spline regression algorithm, the optimal cooling model is fitted. Through positive and reverse experiment verification, the model shows significant effects in controlling internal stress in the crystal and reducing defect generation. Based on this model, we have successfully achieved effective suppression of defects, such as twins and dislocations, thereby significantly improving the quality of InP single crystals. This research not only provides a solid theoretical basis for the production of InP single crystals but also provides strong support for experimental applications.