双坩埚LEC法砷化镓熔体流动与传热传质数值模拟

Numerical Simulation of LEC Growth of GaAs with a Double Crucible

采用低雷诺数κ-ε湍流模型,模拟了双坩埚LEC法砷化镓熔体的流动与传热传质。分析了不同晶体转速、内坩埚转速、外坩埚转速条件下的熔体流动与传热,获得了考虑溶质分凝效应后的Si掺杂在砷化镓熔体中的分布。结果表明:随着晶体转速的增大,生长界面附近等温线更加平直且等温线密度增大;随着内坩埚转速的增大,生长界面附近等温线凸向熔体;外坩埚转速对生长界面等温线形状影响很小;Si在熔体中的质量浓度梯度除生长界面和补充熔体进口处较大外,主要集中在小管内及其附近。

Numerical simulation of the flow and heat and mass transport of GaAs melt in the liquid encapsulant czochralski growth of GaAs single crystal in a double crucible was carried out using the low-Reynolds number κ-ε turbulence model.The effects of crystal rotation rate,inner and outer crucible rotation rate on the flow fields were analyzed.The mass distribution of Si dopant in the GaAs melt was obtained in the case of concenring the dopant segregation effect. The results show that： the isotherms near the melt/ crystal interface tend to be flat and intensive with increasing crystal rotation rate; the isotherms near the melt/crystal interface tend to be convex when increasing inner crucible rotation rate; the influence of the outer crucible rotation rate on the shape of isotherms near the melt/crystal interface is negligible; besides melt/crystal interface and the inlet of replenishing melt, Si concentration gradient mainly occurred in the pipe and its vicinity.