When preparing large monocrystalline silicon materials, severe carbon etching and silicide deposition often occur to the thermal system. Therefore, a suppression method that optimizes the upper insulation structure has been proposed. Assisted by the finite element method, we calculated temperature distribution and carbon deposition of heater and heat shield, made the rule of silicide and temperature distributing in the system, and we explained the formation of impurity deposition. Our results show that the optimized thermal system reduces carbon etching loss on heat components. The lowered pressure of the furnace brings a rapid decrease of silicide deposition. The increase of the argon flow rate effectively inhibits CO and back diffusion. The simulated results agree well with the experiment observations, validating the effectiveness of the proposed method.

中文翻译：

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直拉单晶硅热系统中氧和碳杂质沉积的抑制

在制备大型单晶硅材料时，热系统经常发生严重的碳刻蚀和硅化物沉积。因此，提出了一种优化上部绝缘结构的抑制方法。借助有限元方法，计算了加热器和隔热罩的温度分布和积碳，制定了系统中硅化物和温度分布的规律，解释了杂质沉积的形成。我们的结果表明，优化的热系统减少了热组件上的碳蚀刻损失。炉膛压力的降低带来了硅化物沉积的迅速减少。氩气流速的增加有效地抑制了 CO 和反向扩散。模拟结果与实验观察结果吻合良好，