【作者】 徐进；

【导师】 阙端麟； 杨德仁；

【作者基本信息】 浙江大学 ， 材料物理与化学， 2003， 博士

【摘要】 随着信息社会的不断发展，微电子工业对国民经济发展所起的作用越来越大。半导体硅材料是微电子产业的基础材料，也是信息技术产业的支柱材料，在国家的经济、国防和科技现代化进步方面起着举足轻重的作用。因此，研究硅材料中杂质和缺陷的相互作用，以及热处理时间、温度、气氛和应力对缺陷生成动力学和热力学的影响，对提高集成电路的产率，促进整个微电子产业的发展和进步有着重大而现实的意义。 本文主要通过透射电镜研究直拉硅(氩气氛下生长单晶样品、氮气氛下生长单晶样品、高压(10~9pa)热处理单晶样品、重掺杂单晶样品、快速热处理单晶样品)中氧沉淀及其扩展缺陷的形态、密度和分布随热处理时间、温度、气氛和应力的关系，主要取得以下成果： 首先，本文系统地研究了高压(1GPa)对氧沉淀及其扩展缺陷形成的影响，探讨硅材料中微缺陷形成的微观机制。结果表明：1)在高压(10~9Pa)下经过450℃，10小时处理过的样品中有很高密度的球形极小直径氧沉淀稳定生成，表明高压可以在很大程度上改变氧沉淀的形态；2)四探针电阻仪测试表明，450℃，高压热处理可以促进热施主的生成和提高其生成速率，表明高压可以在很大程度上改变热施主的生成热力学和动力学。这在实验上表明，极小直径的氧沉淀与热施主生成有密切关系。但是，研究发现，650℃，大气压下热处理10分钟就可以完全消除所有样品中的热施主，这表明，高压和大气压下热处理样品中生成的热施主消除特性是一致的。并且，氮杂质对热施主的生成和消除没有显著的影响；3)研究发现，957℃，高压处理5小时的样品中生成了氧沉淀相关的位错，1130℃，高压处理5小时的样品中，有尺度为50nm的氧沉淀生成，表明高压有利于小直径氧沉淀的生成。本文通过分析高压产生的应力对点缺陷生成的影响，对高压热处理过程中产生高密度，小尺寸氧沉淀以及促进热施主的生成做了详细的解释。研究表明，施加在样品上的应力可以在很大程度上改变硅片体内自间隙硅原子和空位的浓度，从而大大影响直拉硅中微缺陷生成的热力学和动力学过程。 随后，本文研究了氮掺杂对直拉硅中缺陷生成的影响。研究表明：1)氮掺杂可以改变原生氧沉淀的形态，透射电镜研究表明，在原生样品中有高密度的粒径只有5nm的多边形原生氧沉淀生成；2)氮掺杂可以在高温和低温过程中促进氧沉淀的生成；3)氮杂质可以影响硅样品中氧化诱生层错的热力学和动力学过程，研究发现，NCZ样品中，随着热氧化时间的增长，层错的尺寸不断减小，而在CZ中，随着热氧化的进行，层错尺寸随着热氧化时间的增长而增加。 最后，本文通过透射电镜系统地研究了在重掺硼样品和轻掺硼样品中，快速热处理工艺对氧沉淀和随后的扩展缺陷生成的影响。研究发现：1)在经历过RTP预处理的重掺硼样品中，有高密度的氧沉淀和层错产生，但是没有经历过RTP快速热处理的重掺硼样品中，只有位错产生。而对普通的轻掺样品来说，经历过RTP快速热处理的样品中有位错产生，但是在未经历RTP预处理的样品中，有氧沉淀相关位错产生；2)研究发现，只有在轻掺杂且经历高温RTP预处理的样品中才有洁净区生成，而在其它样品中，则没有洁净区生成。这表明，高浓度的硼掺杂原子对氧沉淀的促进作用，以及RTP预处理过程中空位体浓度的增加是导致不同缺陷产生的主要原因。更多还原

【Abstract】 Microelectronics based on silicon was driving the high-speed development of economy, science and technology of the world in the last century. As we know, silicon is the most important semiconductor material and it was, is and will also remain the main semiconductor material during the next decades, manifesting that the progress in silicon semiconductor material can influence significantly the economy, national defense and modernization of our country. Thus, it is important to investigate the interaction between the impurities and defects and also the influences of the annealing temperature, ambient, duration and stress on the kinetics and thermodynamics of the generation of defects.In the dissertation, the formation mechanism of the oxygen precipitates and the extended defects generated in Czochralski silicon (Cz-Silicon) specimens were investigated by mean of Transmission Electron Microscopy (TEM). The influence of the annealing temperature, ambient, duration and stress on the distribution, density and morphology of the defects generated in different kind of specimens (including specimens grown under the Nitrogen or Argon ambient, pre-annealed under high pressure of 109 Pa, heavily doped and Rapid thermal annealing (RTA), respectively) have been well investigated and understood.Firstly, the influence of the high pressure pre-annealing on the formation mechanism of the oxygen precipitate and extended defects has been systematically investigated. It found that: 1) Annealing at 450# under high-pressure for 10 hours results in the generation of sphere-like oxygen precipitates with high density but small size, indicating that high pressure can change the morphology of oxygen precipitate to a great extent. 2) It revealed by electrical property measurement that the generation rate and velocity of the thermal donors can be enhanced during annealing at 450癈 under high-pressure, indicating that high pressure can change the formation kinetics and thermodynamics of thermal donors and manifesting that the thermal donors is closely related with the oxygen precipitates with small size. But, it found that the annihilation of the thermal donors generated both in the specimens annealed under atmosphere and high pressure shown no difference, indicating that the annihilation behavior of the thermal donors annealed at 650# is similar. And it also found that the nitrogen doping have no significant influence on the generation and annihilation of thermal donors when annealed at 450# under high pressure. 3) It reveals that oxygen precipitate-related dislocation can be observed in the specimen annealed at 957# under high pressure for 5 hours and oxygen precipitates with the size of about 50nm can be observed in the specimen annealed at 1130# under high pressure for 5 hours, indicating that high pressure can stabilize the oxygen precipitates with small size. By analyzing the influence of the stress induced by the high pressure on the generation of point defects, we propose a detailed and satisfying explanation about the formation of oxygen precipitation with high density but small size and the enhancement of the thermal donors in the specimen annealed under high pressure. It reveals that the stress exerted on specimens by high pressure can change the concentration of point defects, thus influence the formation kinetics and thermodynamics of defects to a great extent.Secondly, the influence of nitrogen doping on the formation mechanism of defects has also been systematically investigated. It found that: 1) Nitrogen doping can change the morphology of grown-in oxygen precipitates. It found that grown-in oxygen precipitates with high density but small size, about 5nm, were generated in nitrogen doping specimen. 2) Nitrogen doping can enhance the oxygen precipitation both in high temperature and low temperature annealing. 3) Nitrogen doping can influence the generation kinetics and thermodynamics of oxidation-induced stacking fault (OSF), it is found that the size of the oxidation-induced stacking faults (OSFs) decreased with th更多还原