【作者】 马巧云；

【导师】 李养贤；

【作者基本信息】 河北工业大学 ， 材料物理与化学， 2005， 硕士

【摘要】 本文中利用傅立叶红外光谱仪(FTIR)、光学显微镜和透射电子显微镜(TEM)观察的方法,研究了辐照剂量、退火条件等因素对快中子辐照直拉硅(CZSi)中氧沉淀及诱生缺陷形成的影响。由于高温退火过程中氧沉淀的生成,辐照样品的常温红外光谱中间隙氧吸收峰向低频端宽化。低温下,宽化的位置分裂出对应于球状氧沉淀和八面体氧沉淀的吸收峰,另外还出现了对应于盘状氧沉淀的吸收峰。快中子辐照直拉硅经高温退火后体内产生了大量氧沉淀诱生的体层错和位错以及辐照引入缺陷诱生的位错环。随着退火时间的延长,氧沉淀诱生层错逐渐长大,同时伴随有新的层错产生。位错环的腐蚀形貌由多条位错线组成,随着退火时间的延长,其形貌变为由一条位错线组成的半环形。延长退火时间,缺陷密度增加。利用TEM观察到多面体氧沉淀,其体内氧原子与硅原子之比为1. 5。首次将快速热处理(RTP)引入到快中子辐照直拉硅的内吸杂工艺中。研究了不同的RTP条件对快中子辐照硅中体缺陷和清洁区的影响。实验发现,RTP未能改变快中子辐照直拉硅中氧沉淀的进程。快中子辐照在硅中引入了大量的空位型缺陷,使快中子辐照直拉硅样品的RTP行为不同于普通直拉硅样品。随着RTP温度的升高,辐照样品中清洁区宽度逐渐变窄。经历氮气氛预处理的辐照样品中有一定宽度的清洁区形成。更多还原

【Abstract】 In this paper, the effects of irradiation doses and annealing conditions on oxygen precipitation and induced defects in fast neutron irradiated Czochralski silicon (CZSi) were studied using Fourier Transform Infrared Absorption Spectrometer (FTIR), optical microscope and transmission electron microscopy(TEM).At room temperature, the absorption band attributed to interstitial oxygen broadened due to the generation of oxygen precipitates. At low temperature, the broadened range split to peaks that attributed to spherical oxygen precipitates and octahedral oxygen precipitates, respectively. The peak, which attributed to the platelet oxygen precipitates appeared, too.Stacking fault, dislocation and dislocation loop appeared in fast neutron irradiated CZSi after annealing at high temperature. The stacking fault and the dislocation are induced by oxygen precipitation. The dislocation loop generates from the irradiation-induced defects. Increasing annealing time, the stacking faults grew and generated. The etching pattern of dislocation loop consisted of several dislocation lines. While with increasing annealing time it changed into semicircular. With increasing annealing time, the density of defects increases. Polyhedral oxygen precipitate was observed by TEM and the ratio of oxygen atoms to silicon atoms was 1.5.Rapid thermal process (RTP) was first used in the intrinsic gettering (IG) process of fast neutron irradiated CZSi. The effects of RTP conditions on bulk microdefects (BMDs) and denuded zone (DZ) was investigated. RTP didn’t change the process of oxygen precipitation and the behavior of the irradiated samples was different from the non-irradiation samples for the vacancy type defects induced by fast neutron irradiation. With increasing RTP temperature, DZ width decreased. DZ formed in the sample that annealed in nitrogen atmosphere.更多还原