| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 99 === The properties and surface textures of the pads would strongly affect the CMP efficiency. Moreover, the grooving design on the pad is an important consideration in pad design. The good grooving design would have several advantages to the CMP process, such as enhance the slurry utility, adjust the slurry film between the wafer and pad, remove the debris from the process and adjust the pad properties. However, the conventional grooving design would not satisfy the process when the process move more and more advancement and require the higher precision and efficiency. In this study, the pad surface would be defined by the bearing ratio parameters and indices, from the analysis of the conventional pads. Base on this analysis, a micro fractal pattern would apply to the pad surface. The purposes of fractal pattern are to reduce the demand of dressing and to enhance the planar efficiency. Experiment results show that the fractal pattern pad could have higher removal rate under the low down-force condition in the Oxide CMP because it has a higher surface bearing index. Moreover, the fractal pattern pad would reduce the dishing and erosion defects when polishing the Cu-patterned wafer. Those processes has verified that the fractal pattern pad can work well to enhance the process efficiency and without dressing. Further study can focus on the TSV-CMP applications for 3D-IC.
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