三氯氢硅(SiHCl3)作为硅外延片的关键原材料，其纯度直接影响着硅外延层的性能。一般三氯氢硅纯度的测试方法有两种，除采用化学分析方法测试外，通常用生长不掺杂外延层(本征外延层)的方法来确定。即采取测量三氯氢硅生长后的硅外延本征电阻率的方法来衡量其纯度。而影响硅外延本征电阻率的主要因素为系统的自掺杂，增加硅外延的生长时间可以有效抑制系统自掺杂，但无限制的增加生长时间必然导致生产成本的增加。文中通过实验数据，确定了一个合理的硅外延本征生长工艺过程，从而达到了评价三氯氢硅纯度的目的。% As the key material, Trichlorosilane (SiHCl3)' purity will directly affect the capability of epitaxy. Usually, two methods for measuring the purity of the Trichlorosilane,one is chemical analysis,the other is measurement of epitaxy intrinsic resistivity after no-doping epitaxial layer growth. The main factor influencing the intrinsic resistivity of epitaxial is the auto-doping. Increase the epitaxial thickness can effectually reduces auto-doping, but will increase the cost with no-planning. In this article discussed the best gorwing process of intrinsic epitaxy for measuring the intrinsic resistivity and the concentration of Trichlorosilane.
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