基于不同阻挡层材料的铜互连热应力有限元分析

Finite element analysis of thermal stress for Cu interconnect with different barrier layer

  • 摘要: 本文利用ANSYS有限元软件分别对用TaN和ZrN作为扩散阻挡层的Cu/barrier/SiO2/Si结构中铜线的热应力分布进行仿真。研究热载荷350℃到20℃不同阻挡层材料单大马士革和双大马士革两种结构铜互连线的热应力。通过仿真结果得到:单大马士革结构中,在阻挡层材料为ZrN时铜线中等效应力(700MPa)比阻挡层材料为TaN时等效应力(800MPa)小;双大马士革结构中,用ZrN作为阻挡层铜线中各个方向的热应力σx、σy和σz分别比TaN作为阻挡层时小100MPa、300MPa和200MPa。本文还研究阻挡层材料分别为ZrN和TaN时,改变阻挡层的厚度对铜线热应力的影响。结果表明,热应力随着阻挡层厚度的增加而增加。各种厚度ZrN作为扩散阻挡层时的应力都比TaN作为扩散阻挡层的应力小,x、y和z方向的应力SX(ZrN)、SY(ZrN)和SZ(ZrN)分别减少了50MPa、200MPa和50MPa。

     

    Abstract: Finite element analysis software ANSYS is applied to simulate the stress distribution in the Cu line with structure Cu/barrier/SiO2/Si,TaN and ZrN as diffusion barrier layer,respectively.The thermal loading is from 350℃ to 20℃,and the stress in Cu single damascus structures and Cu dual damascus structures is discussed.By observing the stress in the Cu line of Cu single damascus structures,Von Mises stress(700MPa) in the structure with ZrN as the diffusion barrier layer is smaller than Von Mises stress(800MPa) in the structure with TaN as the diffusion barrier layer.Compared with the thermal stress with TaN as the diffusion barrier layer in Cu dual damascus structures,σx,σy and σz,the thermal stress in all directions with ZrN as the diffusion barrier layer,is reduced by 50MPa,300MPa and 150MPa respectively.In addition,the effect of barrier layer thickness on thermal stress for Cu line structures with TaN and ZrN as diffusion barrier is studied in this paper.The thermal stress increases with increasing diffusion barrier thickness,and the thermal stress of various barrier thicknesses is smaller in the structure with ZrN as diffusion barrier layer.SX(ZrN),SY(ZrN) and SZ(ZrN),the stress in x,y and z directions,respectively is reduced by 50MPa,200MPa and 50MPa.

     

/

返回文章
返回