| 摘要 |
隨著科技的發展，電子產品往輕、薄、短、小的方向發展，然而線寬越小，越逼近物理極限，製程成本也越高，因此有
More-than-Moore 的概念提出，透過2.5D-IC 與 3D-IC
的構造與技術，讓不同元件可以垂直方向堆疊達到異質整合，縮小體積並提升傳輸速度，其中矽導穿孔在垂直方向訊號傳輸扮演一個重要的角色。目前金屬銅為矽導穿孔廣泛使用填充的金屬之一，但銅與矽晶圓兩者材料的熱膨脹係數相差約六倍之多，因此當填完銅的矽導穿孔晶圓經過高溫的製程時，會因為溫度變化使得銅與矽的膨脹或收縮量不一樣，導致在接觸面周圍產生熱應力，影響元件特性與可靠度。本論文透過拉曼光譜量測應力與有限元素分析法模擬出不同孔徑大小的矽導穿孔在高溫時產生之熱應力，並藉由矽導通孔在出口端圓導角的最佳化設計，有效降低矽導通孔在尖角處應力集中效應，同時，也可以減少熱應力影響區域，增加元件可放置區域面積，提升效益。
關鍵字：矽導通孔、熱應力、圓導角、有限元素法
With the development of
technology, the electronic products become lighter, smaller and
thinner. However, IC manufacturing faces the challenges of
physical limits and the cost of processes become higher.
Consequently, the conception of More-thanMoore is presented and
also allows the Moore’s law to continue. We are able to stack
the chips vertically to provide heterogeneous integration,
increase the speed and reduce form factor by 3D IC and 2.5D TSV
interconnect. The structure of TSV plays an important role in
signal transmission between different chips. Nowadays, copper is
widely used for the metal filling material in TSV structure.
Nevertheless, the coefficient of thermal expansion (CTE) of
copper and silicon are quite different. The CTE of copper is
about six times higher than silicon. While the temperature
changing, the local thermal expansion mismatch would happen. As
a result, it will create large thermal stresses and strains at
the interface between silicon and copper. The thermal stress may
causes the reliability issue and carrier mobility variation. The
finite element analysis (FEA) ANSYS software is used for the all
the simulations in this paper. The simulation results would
compare with the data measured by Raman spectroscopy to verify
the models. Round corner TSV design is added to TSV structure to
reduce the thermal stress at the interface. With this design,
the area of Keep-out-zone could also become smaller and enhance
the performance.
Key words: Through-silicon via
(TSV), Round corner, Thermal stress, Finite element
analysis (FEA)
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