PVT法生长大直径SiC晶体粉源的热特性及对生长的影响

Effects of the Heat Transfer Through Powder Source on the Silicon Carbide Crystal Growth by PVT

研究了SiC粉料的空隙率对晶体生长的影响.分析比较了当粉料取不同空隙率时粉料中以及生长腔内温度分布的异同,并结合实验研究了生长腔内等温线的不同形状和生长晶体表面形貌之间的关系.数值计算和实验结果均表明,生长腔内等温线的形状直接决定着生长晶体的表面形貌;粉源内较大的空隙率有利于粉的有效升华和晶体的稳定生长.

Influences of different porosities in SiC powder source on as-grown crystal are investigated. The temperature distributions in the powder and growth chamber are analyzed for powder sources with different porosities. Combining these results with growth experiments,the relation between the isothermal line and the surface shape of as-grown crystal is also discussed. All simulated and experimental results indicate that the crystal surface shape is determined directly by isothermality in the growth chamber,and that more porosity in the powder is propitious to the evaporation of powder and crystal growth.