A method and device for growing high-quality silicon carbide crystals

Abstract

The invention provides a method and device for growing high-quality silicon carbide crystals. The method includes: (1) assembly stage; (2) heating stage; (3) nucleation stage: keep the temperature at the center of the top of the crucible as T1, control The heat preservation cover moves down along the side wall of the heat preservation cylinder, controlling the temperature difference between the center of the top of the crucible and the edge of the top of the crucible to gradually increase to △T2, so that the silicon carbide raw material is transported to the seed crystal for nucleation in gas phase; (4) Growth stage: The silicon carbide raw material is vapor-phase transported to the seed crystal for crystal growth. In the nucleation stage, the surface of the seed crystal forms an annular temperature field with the center of the seed crystal as the center. By controlling the downward movement of the insulation cover, the annular temperature field is more uniform and stable, and the radial temperature gradient gradually increases slowly, realizing the orientation of the radial temperature gradient Quantitative adjustment gradually increases the radial temperature gradient at the seed crystal, and the joint action promotes the multi-nuclear competition and merger in the nucleation stage, forming uniform and dense growth steps, reducing the probability of crystal defects, and improving the quality of crystal growth.

Description

technical field [0001] The invention relates to a method and a device for growing high-quality silicon carbide crystals, belonging to the technical field of semiconductor material preparation. Background technique [0002] Silicon carbide crystal is a typical wide-bandgap semiconductor material, and it is one of the representatives of the third-generation semiconductor materials after silicon and gallium arsenide. Silicon carbide crystal has excellent properties such as high thermal conductivity, high breakdown field strength, and high saturation electron mobility, and has become one of the popular materials for preparing high-temperature, high-frequency, high-power and radiation-resistant devices. [0003] At present, the methods of silicon carbide growth mainly include physical vapor transport (PVT), liquid phase epitaxy (LPE), chemical vapor deposition (CVD), etc. Among them, PVT method is the most mature method. The growth furnace for the growth of silicon carbide cryst...

AI Technical Summary

Problems solved by technology

In the early stage, the temperature field of silicon carbide crystal growth was unstable, which affected the quality of nucleation and directly affected the growth quality of silicon carbide crystals.

[0004] In the existing method of raising and lowering the crucible during the crystal growth process, the adjustment and control of the temperature field is realized by adjusting the position of the crucible, but the raising and lowering of the crucible will also seriously affect the uniformity and stability of the temperature field, disrupting the silicon carbide atmosphere. Orderly transmission, and will cause the silicon carbide powder in the crucible to vibrate and shift, significantly increase the probability of defects such as polymorphism and inclusions, and reduce the crystallization quality of silicon carbide, etc.

Images