基于碳纳米管的三维集成电路硅通孔互连线的建模与仿真

Three-dimensional (3D) integrated circuit (IC) is the development direction of microelectronics industry and will have a wide range of applications in the near future. Through-silicon via (TSV) interconnect is the key technique to implement 3D integration. However, lots of challenges emerge in conventional metal or polysilicon filling TSV interconnects. Carbon nanotubes have been proved to be a good candidate material for on-chip interconnects in nanoscale ICs, due to their excellent electrical, thermal, and mechanical characteristics. In this proposal, we propose to use bundles of carbon nanotubes as the TSV interconnects in 3D ICs. Based on the basic theories of electromagnetics, circuit, and quantum transport, the parasitic-parameter extraction, equivalent circuit and thermal model, and signal integration of carbon nanotube-based TSV interconnects will be investigated. The key scientific problems including electro-thermal coupling modeling, simulation of signal integration, as well as configuration design and optimization for carbon nanotube-based TSV interconnects will be solved in the project. After that, an equivalent model library suitable for computer aided design (CAD) will be set up. The purpose of this project is to study and reveal the principles of temperature distribution and signal propagation in carbon nanotube-based TSV interconnects by virtue of theorical and numerical modeling. The desired results of this project can be used as a guideline for fabrication of carbon nanotube-based TSV interconnects in real-world 3D ICs, and also provide a theoretical and technical foundation for development of CAD tools for 3D ICs.

三维集成电路是微电子产业发展的主要趋势，具有巨大的潜在应用价值。硅通孔互连是实现三维集成的关键技术。传统金属或多晶硅填充的硅通孔互连线面临诸多挑战，而碳纳米管互连则具有优越的电学、热学和机械特性。本项目以基于碳纳米管的三维集成电路硅通孔互连线为研究对象，拟结合电磁学、电路及量子输运的基本理论，研究碳纳米管硅通孔互连线的寄生电学参数提取、等效电路和热特性建模以及信号完整性分析，重点解决碳纳米管硅通孔互连线的电-热耦合效应模拟、信号完整性仿真与设计优化等对三维集成电路发展起关键作用的问题，创建适用于计算机辅助设计的碳纳米管硅通孔互连模型知识库。本项目旨在用理论与数值模拟的手段研究并揭示三维集成电路中碳纳米管硅通孔互连线的温度分布和电信号传播规律，为实际制备碳纳米管硅通孔互连线提供理论指导，为开发三维集成电路计算机辅助设计工具奠定一定的理论和技术基础。

随着集成电路器件特征尺寸和最小线宽逐渐趋近于其物理极限，传统的平面集成电路的集成度难以进一步提高，而基于硅通孔的三维集成电路则成为进一步提高集成度，推动集成电路往高性能、低功耗方向发展的解决方案。本项目围绕三维集成电路硅通孔互连线的建模与仿真开展研究，重点结合电磁学和电路的基本理论，研究三维集成电路硅通孔互连线的寄生电学参数提取、等效电路建模以及信号完整性。. 本项目的主要创新性贡献包括：(1)提出了同轴型、圆环型、差分型等三类硅通孔互连线的宽频带电学参数解析计算方法和等效电路模型。（2）研究了铜、单壁碳纳米管束、多壁碳纳米管束等不同材料填充硅通孔互连线的电学参数提取方法和互连性能比较，建立了温度相关的电学参数计算模型并分析了温度对互连性能的影响。（3）提出了适用于通用色散介质环境中互连线寄生参数提取的时域有限差分全波电磁仿真算法。(4)研究了三维集成中加载的导电薄膜或周期屏蔽结构与电磁波相互作用的量化计算问题。. 该项目的研究成果可为下一代高速集成电路中硅通孔互连线的设计与制备提供理论指导，为三维集成电路计算机辅助设计工具的开发奠定一定基础。.上述研究结果得到了国际同行的认可，共发表论文11篇，其中SCI收录8篇，培养研究生4名。较圆满地完成了项目研究计划。