文档介绍：本科学生毕业论文
论文题目:
应力与本征缺陷影响硅晶体电学性质机理第一性原理研究
学院:
电子工程学院
年级:
2009级
专业:
电子科学与技术(微电子)
姓名:
李册
学号:
20096647
指导教师:
李青坤
2013 年 5 月 10 日
摘要
如今对于半导体材料硅的研究已经日渐成熟,硅已经是最广泛应用的一类半导体,在微电子和集成电路行业中硅占据着主导地位,通常通过掺杂杂质来改变硅的导电性能,硅的掺杂技术已经被普遍应用并且越来越成熟,并制成各种器件。然而在应力和本征缺陷对硅的电学性质的作用却很少提及。在对半导体材料的研究和学习中可知,缺陷的电学特性对半导体也有着一定的影响,参杂原子可以提供载流子提高其导电特性,而空位等缺陷在禁带中产生深能级,因此缺陷影响着半导体的禁带宽度和载流子数目。因此缺陷对硅的导电特性起着至关重要的作用。当对硅晶体某一晶向上施加一个拉伸或压缩的应力时会对硅结构造成一定的影响,导致禁带宽度会发生变化,使其导电性能也发生变化。
本文所进行的工作就是研究应力和本征缺陷双重因素作用下影响硅电学性质机理的第一性原理的研究。利用Materials Studio 软件来计算分别对硅的<111>和<100>晶向施加拉伸和压缩的应力其电学性质变化并绘制应力随应变曲线,并且绘制出能带图、态密度图、分波态密度图,进一步解释其应力和本征缺陷对硅导电性质机理的影响。从而寻找不依赖掺杂而只利用本征缺陷和应力来调控硅的电学性质的方法。利用应力和本征缺陷调节硅的禁带宽度改变半导体的性能并通过能带图、分波态密度图、态密度图进行理论分析其机理。并解释应力和本征缺陷作用下硅晶体宏观现象的微观本原,并为硅工业发展提供理论支持。
关键词
第一性原理;硅;本征缺陷;应力
Abstract

Now for the study of semiconductor silicon is more and more mature, silicon is the most widely used a kind of semiconductor. Silicon in microelectronics and integrated circuit industry occupy a dominant position. Typically by doping the impurity to change the conductivity of the silicon, the silicon doping technique has been widely applied and the more mature. And make into a variety of devices. But the role of stress and intrinsic defects in the electrical properties of silicon is rarely mentioned. As known in the semiconductor materials research and study , the electrical properties of defects has a certain impact on the semiconductor, impurity atom may provide the carrier to improve its conductive characteristics. While vacancies and other defects in the formation of deep levels in the band gap, defect affecting the band gap of the semiconductor and the number of carriers. Therefore, defect in the electrical properties of silicon plays a vital role. When applied a tensile pressive stress on a particular crystal orientation of the silicon and crystal silicon structures have been affected. Band gap will change also its conductive properties.
The work of this paper is to study stress and intrinsic d