Modeling and Control of Wafer Scale Yield Improvement in Chemical Mechanical Planarization (CMP)

该项目的目标是通过在化学机械平坦化过程中提高材料去除速度的晶片尺寸一致性来提高IC制造中的晶片良率。减少和消除边缘排斥对本项目特别有意义。将采用基于模型的综合控制方法。建立了材料去除率与晶片-焊盘界面压力和晶片背面载荷分布之间的解析模型。模型的预测将首先在静态条件下进行验证，并根据材料去除速率数据进行验证。基于上述模型，将开发出一种主动控制算法。特别是，曲率控制算法将被采用。这将首先在软件中实现，然后在硬件中实现。预计该项目将发展对化学机械平坦化过程的纳米级细微差别与宏观设计考虑之间的联系的理解。这将促进工艺参数的有效优化和控制，目前这主要是通过试错迭代完成的。通过产学合作，拟议的项目将通过让研究生和本科生接触控制纳米材料去除过程的新方法来帮助人力资源开发。目前，3-5 mm的晶片边缘排除器被用来收集晶片上的“可用”芯片，这会影响到300 mm晶片上约20%的芯片。如果成功，该项目将直接影响和提高这些过程的产量。

The objective of this project is to enhance wafer yield in IC manufacturing by enhancing the wafer scale uniformity in material removal rate during a chemical mechanical planarization process. Reduction and elimination of edge exclusion is of particular interest to this project. An integrated model based control approach will be pursued. An analytical model relating the material removal rate to the wafer - pad interface pressure and wafer backside loading profile will be developed. The model predictions will be verified first under static conditions and from material removal rate data. An active control algorithm based on the above model will be developed. In particular, the curvature control algorithm will be pursued. This will be implemented first in software, and then in hardware.It is anticipated that this project will develop understanding to relate nano-scale nuances of the chemical mechanical planarization process to macro-scale design considerations. This will facilitate efficient optimization and control of process parameters, which is currently done mostly through trial and error iterations. Through Industry-University collaboration, the proposed project will aid in human resource development by exposing graduate and undergraduate students to novel methods of controlling nano-scale material removal processes. Currently a 3-5 mm wafer edge exclusion is used to harvest "usable" chips on wafers, and this affects about 20 percent of the chips on a 300 mm wafer. If successful, this project will directly impact and enhance the yield of such processes.