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通过对比研究重掺砷直拉硅片和轻掺n型直拉硅片经过低温(450—800℃)和高温(1000℃)两步退火的氧沉淀行为,阐明了低温退火对重掺掺砷直拉硅片的氧沉淀形核的作用.研究指出:重掺砷硅片在450℃和650℃退火时的氧沉淀形核比在800℃退火时更显著,这与轻掺硅片的情况截然相反;此外,与轻掺硅片相比,重掺砷硅片在450℃和650℃退火时氧沉淀的形核得到增强,而在800℃退火时氧沉淀的形核受到抑制.分析认为,重掺砷硅片在450℃和650℃退火时会形成砷-空位-氧(As-V-O)复合体,它们促进了氧沉淀的形核;而在800℃退火时As-V-O复合体不能稳定的存在而缺少氧沉淀形核的前驱体,并且重掺砷会导致硅晶体中的晶格压应力,因此氧沉淀形核被显著地抑制.实验还表明,在重掺砷硅片中掺入氮杂质可以促进低温退火时的氧沉淀形核,这种促进作用在800℃退火时表现得更加明显,这与氮引入的异质形核中心有关.
The effects of low-temperature annealing on the arsenic-doped arsenic-doped arsenic were studied by comparing the oxygen deposition behaviors of heavily-arsenic-doped Czochralski silicon and light-doped n-type czochralski silicon after low temperature (450-800 ° C) and high temperature (1000 ° C) Oxygen precipitation nucleation of Czochralski silicon wafers was investigated.The results show that the oxygen precipitation nucleation of the heavily arsenic wafers annealed at 450 ° C and 650 ° C is more pronounced than that at 800 ° C, In contrast, the nucleation of oxygen precipitates was enhanced when the arsenic wafers were annealed at 450 ℃ and 650 ℃ compared with the lightly doped silicon wafers, while the nucleation of oxygen precipitates was inhibited when annealed at 800 ℃ .At the same time, , As-VO (As-VO) composites formed at 450 ℃ and 650 ℃, which promoted the nucleation of oxygen precipitation. However, As-VO composite could not anneal at 800 ℃ Stable existence and lack of precursors of oxygen precipitation nucleation, and heavy arsenic will lead to crystal lattice stress in the silicon crystal, so the oxygen precipitation nucleation is significantly inhibited.Experiments also show that in the heavily doped arsenic wafer doping Nitrogen impurities can promote the nucleation of oxygen precipitation during low temperature annealing, which is more obvious when annealed at 800 ℃. Into the heterogeneous nucleation center.