Mechanics of Chemical-Mechanical Polishing for Microelectronic Materials

该补助金为化学机械抛光（CMP）过程中材料去除机制的基本理解提供资金，CMP是制造具有0.5微米线尺寸的多层金属化集成电路（IC）的必要工艺步骤。 该项目将利用实验和分析工作相结合。 纳米级压痕和单粒划痕实验将在实验室规模进行，使用原子力显微镜（AFM）与工件的尖端的干扰。 这些AFM测试的观察结果将在CMP过程的机械模型中合成。 该模型将根据与工业合作伙伴合作进行的全规模CMP操作的实验观察进行验证。 将测试均匀和图案化的晶片，并且将根据这些CMP测试期间进行的特征尺度和晶片尺度测量来进一步改进模型。 将进行详细的参数研究，并验证模型，然后将被用来寻求新的设计途径，进一步改善CMP技术。 特别是，各种工艺参数对非均匀性程度的影响（芯片规模和晶圆规模）的局部材料去除率。如果成功，该研究将促进CMP技术在三个不同途径的发展：（1）它将有助于确定材料和工艺参数之间的主要因果关系，以及CMP工艺的有效性（通过完成表面的质量和完整性测量）和效率（通过材料去除速率测量）。 这样的机理描述将提供CMP中的材料去除过程的基本理解，并促进工艺优化。 (2)该模型，通过其机械的描述，将有助于减轻障碍，并将有利于更灵活地使用实验收集的数据，为现实的CMP工艺。 (3)除了提供对CMP工艺的更基本的理解之外，实验和建模工作的价值在于其增强的探索“设计空间”的能力。 目前，许多工艺设计选项（例如，浆料和垫性质的最佳选择）由于缺乏描述这些效果的可靠模型而仍然是试错程序。 该模型将有助于识别这些未开发的工艺参数，并指导设计CMP工艺的新途径。 这种探索新的设计途径的能力可能会为CMP工艺和相关设备的有效和高效设计提供新的动力。

This grant provides funding for the development of fundamental understanding of the mechanics of material removal during Chemical Mechanical Polishing (CMP), which is a necessary process step in fabrication of multilevel metallizations integrated circuits (IC) with sub 0.5 micron line dimensions. The project will utilize a combination of experimentations and analytical efforts. Nanoscale indentation and single grit scratch experiments will be conducted at the laboratory scale using the interference of an atomic force microscope (AFM) tip with the workpiece. The observations from these AFM tests will be synthesized in a mechanistic model of the CMP process. The model will be validated against experimental observations from a full scale CMP operation conducted in collaboration with industrial partners. Both uniform as well as patterned wafers will be tested, and the model will be further refined in view of the feature scale and wafer scale measurements taken during these CMP tests. Detailed parametric study will be conducted, and the validated model will then be utilized to seek new design avenues for further improving the CMP technique. In particular, the effects of various process parameters on the degree of nonuniformity (die scale and wafer scale) of local material removal rate will be investigated.If successful, the research will facilitate CMP technology development in three different avenues: (1) It will aid in identifying the dominant causal relationships between the material and process parameters, and the effectiveness (measured by quality and integrity of the finished surface) and efficiency (measured by material removal rate) of a CMP process. Such a mechanistic description will provide a fundamental understanding of the material removal process in CMP, and facilitate process optimization. (2) The model, through its mechanistic description, will aid in alleviating impediments and will facilitate a much more versatile use of experimentally gathered data for realistic CMP processes. (3) In addition to providing a more fundamental understanding of the CMP process, the value of the experimental and modeling efforts lie in its enhanced capability for exploration of the "design space". Currently, many process design options (e.g. optimum selection of slurry and pad properties) remain a trial and error procedure due to lack of reliable models depicting those effects. The model will aid in identifying such unexplored process parameters, and guide toward new and novel avenues for designing CMP processes. This capability to explore new design avenues may have the potential to provide a new impetus to effective and efficient designs of CMP processes and related equipment.