Zhao Kai, Hu Yuanzhao, Du Gang, Zhao Yudi, Dong Junchen
Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument, Beijing Information Science and Technology University, Beijing 100101, China.
Huantian Technology (Kunshan) Electronics Co., Ltd., Kunshan 215300, China.
Nanomaterials (Basel). 2022 May 21;12(10):1760. doi: 10.3390/nano12101760.
The resistivity of Cu interconnects increases rapidly with continuously scaling down due to scatterings, causing a major challenge for future nodes in M0 and M1 layers. Here, A Boltzmann-transport-equation-based Monte Carlo simulator, including all the major scattering mechanisms of interconnects, is developed for the evaluation of electron transport behaviors. Good agreements between our simulation and the experimental results are achieved for Cu, Ru, Co, and W, from bulk down to 10 nm interconnects. The line resistance values of the four materials with the inclusion of liner and barrier thicknesses are calculated in the same footprint for a fair comparison. The impact of high aspect ratio on resistivity is analyzed for promising buried power rail materials, such as Ru and W. Our results show that grain boundary scattering plays the most important role in nano-scale interconnects, followed by surface roughness and plasma excimer scattering. Surface roughness scattering is the origin of the resistivity decrease for high-aspect-ratio conductive rails. In addition, the grain sizes for the technical nodes of different materials are extracted and the impact of grain size on resistivity is analyzed.
由于散射，随着不断缩小尺寸，铜互连的电阻率迅速增加，这给M0和M1层的未来节点带来了重大挑战。在此，开发了一种基于玻尔兹曼输运方程的蒙特卡罗模拟器，其中包括互连的所有主要散射机制，用于评估电子输运行为。对于从块体到10nm互连的铜、钌、钴和钨，我们的模拟结果与实验结果达成了良好的一致性。为了进行公平比较，在相同的占位面积下计算了包含衬垫和势垒厚度的这四种材料的线路电阻值。针对有前景的埋入式电源轨材料，如钌和钨，分析了高纵横比对电阻率的影响。我们的结果表明，在纳米级互连中，晶界散射起最重要的作用，其次是表面粗糙度和等离子体准分子散射。表面粗糙度散射是高纵横比导电轨电阻率降低的原因。此外，提取了不同材料技术节点的晶粒尺寸，并分析了晶粒尺寸对电阻率的影响。
