Application of measurement method on Cu-CMP process

Chemical Mechanical Polishing (CMP) is considered the only processing technique that can achieve high level of local and global planarity of wafer surface and therefore widely used on IC manufacture industry [1]. However, It becomes more difficult but important to monitor CMP process performance well. In this paper, Metapulse (provided by Rudolph) and Aleris8350 (provided by Kla-Tencor) were used to monitor Cu-CMP process. The theory and characteristic of these two measurement tools were studied by using two typical monitor structures (OCD pad and Bond pad) to monitor Cu-CMP process. Performance evaluation is based on mean, range, and uniformity. Our results show that Aleris8350 is suitable for dielectric measurement to reflect topography performance of the whole wafer and Metapulse has advantage in thickness measurement for both OCD pad and Bond pad.