Ultrasonic Vibration and Water-Jet Assisted Diamond Disk Dressing Characteristic of CMP Polishing Pad
| Autor: | Wei-Zheng Yang, 楊緯政 |
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| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 This study introduces an ultrasonic, vibration-assisted, chemical mechanical polishing (UV-CMP) method to improve the fabrication process and machining efficiency and an ultrasonic, vibration-assisted, diamond disk (UV-DD) method to enhance the diamond work number, then extension diamond disk life. The removal rate of the copper substrate in CMP and UV-CMP are compared. The pad cut rate, friction force, and pad surface profiles of TDD and UV-DD are also investigated in experiments. In addition an experimental investigation of the dressing characteristics of a porous polishing pad using a combination process of high-pressure water jet conditioning (HPWJC) and diamond disk conditioning (DDC) is also investigated. The HPWJC and DDC dressing mechanisms were integrated to improve the dressing efficiency. Experimental results reveal that UV-DD can produce twice the pad cut rate and reduce torque force compared to TDD. Consequently, a dressing time reduction by half is expected, and hence, the diamond life is extended. The removal rate of the copper substrate polished by UV-CMP is higher than that of traditional CMP because in UV-CMP, a passive layer on the copper surface, formed by the chemical action of the slurry, will be removed not only by the mechanical action of CMP but also by ultrasonic action. In addition, the surface roughness improves and the torque force reduces dramatically. It is found that although the HPWJC can clean the slurry residue from the pad surface and consumes less pad material, it cannot remove the glazed area layer formed as a result of plastic deformation. DDC can eliminate the pads glaze layer and restore the pad asperities, but some residual chips still remain the sides of the pores or inside the pores. HPWJC + DDC can not only remove the embedded slurry particulates and glazed layer, but also clean the slurry residue accumulated on the pad surface, and regenerate the pad asperities. In addition, the chip roughness in the pores, created by the diamond grit, are completely removed by the HPWJC + DDC conditioning process, which helps achieve the highest material removal rate. In summary, UV-CMP, HPWJC and UV-DD technology has the potential to be effectively used as a wafer polishing and pad conditioning method. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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