Effect of Diamonds on Pad Recovery in Oxide and Metal Pad Conditioning Process

The asperity and roughness of a pad surface have an effect on removal rate and uniformity of wafer surfaces during CMP process. The regeneration or conditioning of pad surfaces during and after CMP is required to maintain the removal rate and uniformity constant. In conditioning process, the rate of pad recovery can be determined by characteristics of diamond on metal disk such as the size, shape, density and arrangement of diamonds. However, root causes affecting pad recovery in oxide and metal conditioning have not yet reported due to its proprietary nature. In this study, the efficiency of pad recovery was evaluated at different size, density, shape and arrangement of diamonds on conditioner disk in metal and oxide pad conditioning process. In oxide conditioning, the larger size and higher density of diamonds on conditioner, the higher pad recovery rate was measured. In metal conditioning, the smaller diamond size, and lower density, the higher recovery rates.