直拉硅单晶制备中来自于石英坩埚的受主杂质污染定量分析

The Quantitative Analysis of Acceptor Impurity Pollution from Quartz Crucible in Preparation of CZ-Si

半导体硅单晶制备中一般要求掺入一定量的杂质以控制其电阻率。但是,由于坩埚受熔体侵蚀引入杂质污染,影响硅棒的实际电阻率,降低产品合格率。特别对于连续拉晶过程中,长时间的熔体侵蚀造成硅棒尾部杂质含量急剧升高。讨论了由于石英坩埚中受主杂质污染对硅单晶棒电学性能的影响,并对杂质渗入量进行了定量分析。结果表明,随着晶体生长时间的延长,石英坩埚的Ba涂层被破坏,杂质的渗入速率快速增加。试验中杂质总渗入量超过700μg。

In the preparation of semiconductor silicon single crystal, it is required to mix a certain impurities into the process to control its specific resistance. But, the impurities pollution is introduced into the crucible due to the melt erosion, its affects the practical specific resistance of the silicon rod, so that the qualified rate of the products are reduced. Especially, in the process of continuous crystal pulling, the long melt erosion causes the impurities content increases drastically at the end of the silicon rod. Due to the acceptor impurity pollution, the effect of the quartz crucible on the electrical properties of the silicon single crystal red is discussed, and the quantitative analy- sis is made for the infiltration capacity. The results show, the Ba coating of quartz crucible is damaged along with the prolonged growth time of crystal, the impurities infiltration speed is increased rapidly. In the test, the total infiltration capacity of impurities is over than 700μg.