Study on Cu CMP method using the superconductive assisted machining

Abstract We developed a polishing method for Cu CMP using superconductive assisted machining (SUAM) with magnets levitated in air. SUAM enables a non-contact pressure system by utilizing the pinning effect of superconductivity to polish Cu-electroplated films for backend processing. This method offers several key advantages: reduced dust generation, polishing at room temperature, and precise pressure control between the polishing pad and wafer, based on the contact area and holding force resulting from the pinning effect. The results indicate that, similar to conventional Cu CMP, the polishing rate with SUAM is proportional to both pressure and rotational speed, particularly in high-pressure regions, demonstrating its effectiveness.