低阻硅TSV与铜填充TSV热力学特性对比分析

对低阻硅TSV以及铜填充TSV的热力学性能通过有限元仿真的方法进行对比分析.低阻硅TSV在绝缘层上方以及低阻硅柱上方的铝层区域中凸起最为显著，且高度分别为82 nm和76 nm；铜填充TSV的凸起位置主要集中在通孔中心铜柱的上方，最大值为150 nm.应力方面，低阻硅TSV在绝缘层两侧的应力最大，且最大值为1 005 MPa；铜填充TSV在中心铜柱外侧应力最大，且最大值为1 227 MPa.另外，两种结构TSV的界面应力都在靠近TSV两端时最大.低阻硅TSV界面应力没有超过400 MPa，而铜填充TSV在靠近其两端时界面应力已经超过800 MPa.综上所述，相比于铜填充TSV，低阻硅TSV具有更高的热力学可靠性. 

Thermal-Mechanical Reliability Characterization of Low-Resistivity Silicon-TSVs (LRS-TSV) and Copper-Filled TSVs

The thermal mechanical reliability of low resistivity silicon through silicon via (LRS-TSV) and copper-filled TSV was analyzed and compared based on finite element method (FEM). The results show that, the protrusion area of LRS-TSV emerges mainly upon polymer insulation and the aluminum layer above the silicon pillar, the height is 82 nm and 76 nm respectively. The protrusion area of copper-filled TSV emerges mainly upon the copper layer above the copper pillar, the maximum value is 150 nm. The largest stress of the LRS-TSV emerges on both sides of the polymer insulation layer, the maximum value can reach up to 1 005 MPa. And the largest stress of Copper-filled TSV emerges on the outside of the central copper pillar, the maximum value is 1 227 MPa. In addition, the largest interfacial stress of the two types of TSV structure all appears at both ends near the TSV. The stress of the LRS-TSV can not exceed 400 MPa, while the stress of copper-filled TSV can exceed 800 MPa. Based on the above results, it is concluded that the LRS-TSV possesses higher thermal mechanical reliability than the copper-filled TSV.