SHF: Small: Collaborative Research: Design for Manufacturability for 3D ICs with Through Silicon Vias

直通硅通孔(TSV)提供了在3D IC中以精细的粒度在多个芯片上布置不同种类元件的可能性。这可能会导致整体导线长度、延迟、功率和外形系数显著降低。然而，与其他布局对象相比，TSV的尺寸较大，导致各层中的密度分布明显不均匀。此密度问题预计会在化学机械抛光(CMP)过程中造成问题，并需要TSV感知的解决方案。此外，在TSV制造和电路操作期间，TSV铜和硅之间的CTE(热膨胀系数)不匹配会对附近的器件造成显著的热机械应力。这进而影响设备的时序和功率特性。衬底和器件的机械可靠性也受到TSV的影响。然而，对于需要改变哪些设计工具和方法来提高基于TSV的3D IC的可制造性，我们知之甚少。本项目将研究3D IC集成的三个关键DFM/DFR领域，即TSV诱导的应力效应及其对整体电路时序和功率的影响、TSV对化学机械抛光和光刻的影响以及TSV诱导的可靠性。该项目的成功完成将有助于我们深入了解3D IC和TSV技术的可制造性和可靠性问题，并开发有效的物理设计解决方案来克服这些问题。该提案呼吁3D IC的可制造性和可靠性建模、仿真和验证领域的研究人员与电路和物理设计领域的研究人员之间进行非常强有力的合作。

Through-Silicon-Via (TSV) provides the possibility of arranging heterogeneous components across multiple dies at a fine level of granularity in 3D ICs. This can result in significant decrease in the overall wire length, delay, power, and form factor. Primarily due to their large size compared with other layout objects, however, TSVs cause significant non-uniform density distribution in various layers. This density issue is expected to cause trouble during chemical mechanical polishing (CMP) and require TSV-aware solutions. In addition, the CTE (coefficient of thermal expansion) mismatch between TSV copper and silicon causes significant thermal mechanical stress to the devices nearby during TSV manufacturing and circuit operation. This in turn affects the timing and power characteristics of the devices. The mechanical reliability of the substrate and devices are also affected by TSVs. However, little is known on what design tool and methodology changes are required to improve the manufacturability of TSV-based 3D ICs. This project would investigate three key DFM/DFR areas specific to 3D IC integration, namely, TSV-induced stress effect and its impact to the overall circuit timing and power, TSV impact to CMP and lithography, and TSV-induced reliability. Successful completion of the project would help us to gain in-depth understanding of manufacturability and reliability issues with 3D ICs and TSV technology and develop effective physical design solutions to overcome these issues. The proposal calls for a very strong collaboration between the researchers from the manufacturability and reliability modeling, simulation, and validation area and the researchers from circuit and physical design area for 3D ICs.