Comparison of two different conditioning disk designs in reference to cost of ownership of tungsten CMP

摘要

The process of pad conditioning is an important part in the sphere of CMP. A pad conditioner is often used to remove polishing debris, and hence preventing the pad surface from glazing. The proper conditioning can assure the pad surface like new so it can hold slurry evenly for effective polishing (1). With the skillful selection of conditioning tools, consistence of pad properties can be improved and Cost of Ownership (CoO) can be reduced significantly. In order to optimise the W CMP process with regard to CoO, two different conditioning disks have been tested to prove their effectivity. This paper presents a comparison of the process results by the two different conditioning disks. Tungsten removal rate, uniformity and process stability are provided as a function of polishing pad life. In addition, Scanning Electron Microscope (SEM) images are provided to show the impact of the different conditioning disks on the pad surface and the influence of the number of conditioning cycles on the aging of the conditioning disk and polishing pad.