【作者】 奚鹏程；

【导师】 戴显英；

【作者基本信息】 西安电子科技大学 ， 微电子学与固体电子学， 2011， 硕士

【摘要】 应变SiGe和应变Si以其相对于体Si的诸多优点,成为遵循摩尔定律发展的新材料技术。由于SiGe与衬底之间存在较大的晶格失配,所以异质外延得到的薄膜往往具有很高的位错密度,这些位错极大地限制了器件的性能和可靠性。为了更好的降低和控制穿透位错密度,对硅基应变与弛豫材料缺陷机理及表征方法的研究显得尤为重要。论文深入研究了硅基应变与弛豫材料中各种缺陷机理,重点对其中位错缺陷的类型、形成机理、特征、行为、成核及增殖机制进行了研究,同时还对缺陷的观察及位错密度的表征方法进行了重点研究。本文中硅基应变与弛豫材料由RPCVD设备生长,使用透射电子显微镜对材料内部的缺陷及行为进行研究分析,通过腐蚀法对位错密度进行表征研究。实验结果表明,Ge组分梯度渐变缓冲层工艺和低温Si缓冲层工艺能大大降低穿透位错的密度。通过改变腐蚀液配方及腐蚀时间等实验对表征方法进行了研究,提出了使用梯度腐蚀法测量位错密度。通过使用梯度腐蚀法,可以在同一个样片上进行多个时间的腐蚀实验,对比不同腐蚀时间样片的腐蚀效果,方便确定不同层结构样品的腐蚀时间,提高腐蚀后样片的观测效果。更多还原

【Abstract】 Strained SiGe and strained Si is a better kind of material and technology than Si CMOS to keep on with the Moore’s Law. Due to the large lattice mismatch between the layer and the substrate, the epitaxial film often receives a high dislocation density, which greatly degrades the device performance. For Reducing and controlling the threading dislocation density, it is necessary to have a research on defect mechanism and characterization for Si based strained and relaxed materials.We researched into the shape, formation mechanism, character, behavior, nucleation and multiplication mechanism of dislocation in Si based strained and relaxed materials, we also have a good research on the observation of the defect and the characterization of dislocation density.In this work we used the RPCVD device to epitaxial the Si based strained and relaxed materials, the behavior of defect are analyzed by TEM and the density dislocation was characterized by etching. According to the results of research, Ge component gradual changing buffer layer technology and low temperature Si buffer layer technology can both greatly reduce the threading dislocation density.To get a better etch result, we did a lot of experiments by changing etching solution and etching time. We proposed the ideal of gradient etching .By this method ,we can do many experiments in one sample, determine the etching time with different layer structure easily,and it can improve the observe result of etching.更多还原