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直拉硅中氧的浓度高达10~(18)at/cm~3,在器件工艺的热处理过程中,会产生氧的沉淀或形成硅氧团(SiO_x)。经过650℃下较长时间热处理所形成的与氧有关的缺陷,在表观上起施主陷阱中心的作用,引起硅片电阻率的漂移,影响器件的阈值电压,降低VLSI的成品率。近些年来,人们越来越注重研究施主陷阱的产生及其微观结构。这一方面是由于VLSI生产向低温工艺发展后,不可避免地会遇到施主陷阱问题,另一方面,新近的研究表明,在较低温度退火中形成的施主陷阱或硅氧团,在器件的后续工艺中,会成为氧进一步沉淀的核心,促进了更为复杂的沉淀物一位错络合物(PDC)的形成。因此研究在较低温度(例如650℃左右)热处理所形成的微缺陷的性质、结构及其它杂质对它生成的影响,无疑对弄清硅中与氧有关施主陷阱的本质,对改善用于VLSI器件的材料性能,都会具有十分重要意义的。
Czochralski silicon oxygen concentration as high as 10 ~ (18) at / cm ~ 3 in the device process of heat treatment, will produce oxygen precipitation or the formation of silicon oxide (SiO_x). After 650 ℃ for a long time under the heat treatment formed oxygen-related defects in the apparent role of the donor trap center, causing the wafer resistivity drift, affecting the threshold voltage of the device, reducing the VLSI yield. In recent years, people pay more and more attention to the production of donor trap and its microstructure. This is partly due to the inevitable encounter of donor traps after the VLSI production has been developed for low temperature processes. On the other hand, recent studies have shown that donor traps or sili- cs formed in lower temperature anneals, Subsequent processes, at the heart of further oxygen precipitation, facilitate the formation of a more complex precipitate, a dislocation complex (PDC). Therefore, studying the influence of the nature, structure and other impurities of the micro-defects formed by the heat treatment at a relatively low temperature (for example, about 650 ° C.) undoubtedly helps clarify the oxygen-related donor trap in silicon, The material properties of the device, will be of great significance.