Si中30°部分位错和单空位相互作用的分子动力学模拟  

MOLECULAR DYNAMICS SIMULATION OF THE INTERACTION BETWEEN 30°PARTIAL DISLOCATION AND MONOVACANCY IN Si

作　　者：王超营 孟庆元[1] 王云涛[1] 

机构地区：[1]哈尔滨工业大学航天科学与力学系,哈尔滨150001

出　　处：《金属学报》2009年第4期400-404,共5页Acta Metallurgica Sinica

基　　金：国家自然科学基金资助项目10772062~~

摘　　要：利用基于Stillinger-Weber(SW)势函数的分子动力学方法分析了Si中30°部分位错和单空位(V_1)的相互作用.不同温度、剪应力作用下的计算结果表明,在温度恒定条件下,剪应力较小时,V_1对位错有钉扎作用;当施加的剪应力达到临界剪应力时,位错脱离V_1的钉扎继续运动,并且将V_1遗留在晶体中;随温度的升高,临界剪应力近似线性下降.通过不含V_1和含有V_1的模型中位错芯位置的对比后发现,V_1对滑过它的30°部分位错有明显的加速怍用.Dislocation and monovacancy （V1） are the fundamental defects in Si. The interaction between them is concerned with the electronic and optical properties of electronic devices. In this paper, the interactions of 30° partial dislocation with V1 in Si were investigated by the molecular dynamics simulation method based on the Stillinger-Weber （SW） potential. The simulations were conducted under different temperature and shear stress conditions. The results show that 30° partial dislocation is pinned when dislocation encounters the V1 under the conditions that shear stress is relatively low and the temperature is kept constant. When the shear stress increases to a critical value, the dislocation can overcome the pin and the Vi is left in the crystal. As the temperature increases, the critical shear stress decreases approximately as a linear function. Moreover, the values of the critical shear stress corresponding to different dislocation kinks also show that the abilites of kinks to overcome the pin are determinded by the migration barriers of kinks. In comparison of the locations of dislocation core in two models with and without V1, it is found that the Vi can make the 30° partial dislocation move faster once the dislocation glides away from the V1.

关 键 词：SI 30°部分位错 单空位 分子动力学 弯结 

分 类 号：O411.3[理学—理论物理] O77[理学—物理]