施主态氧沉淀的微观分布

本文利用扩展电阻研究了低温退火及低-高温二步退火后P-CZ硅中新施主的微观分布。指出在新施主的氧沉淀界面模型下,通过扩展电阻法测量新施主的分布提供了确定氧的微小沉淀的一个灵敏的方法,其灵敏度取决于原始电阻率,新施主的分布可以通过讨论氧沉淀的分布,氧沉淀动力学过程以及晶体生长的液流模型得到解释。

MICRODISTRIBUTION OF NEW DONOR IN P-CZ SILICON

The microdistribution of new donor in P-CZ silicon crystals after low tempe-rature annealing or low-high temperature two steps heat-treatment,has been studiedby spreading resistance.It is demonstrated that,for the Si/SiO_2 precipitate inter-face model of new donor,spreading resistance method could be a sensitive methodto determine the distribution of microprecipitates of oxygen.The sensitivity dependson the resistivity of as-grown samples.The distribution of new donor can beexplained by discussing the distribution of oxygen precipitates,the kinetics of prec-ipitation and the liquid-flow model during crystal growth.For samples with lowoxygen content,spreading resistance shows the formation of new donor while nochange has been observed in four-points probe resistivity measurement.The distri-bution of new donor in middle-oxygen content samples is found to be consistentwith the anticipated distribution for oxygen by liquid-flow model of crystalgrowth.There exists new donor in as-grown high oxygen content samples.It isshown that at the initial stage of low temperature annealing,the growth of nucleiis predominant in the formation of new donor or the precipitation of oxygen.Thethermal stability of new donor is further expressed by spreading resistance of middleoxygen content samples.It is found that the inhomogeneity of resistivity caused bylow temperature annealing still exists after high temperature annealing.