Effect of Diamond Oxidation Temperature on the Performance of a Diamond Disk in Chemical Mechanical Polishing

摘要

A new design for a chemical mechanical polishing diamond disk that has markedly improved diamond sharpness is proposed in this study. Initially, the diamond is heated at different temperatures (850℃, 900℃, and 950℃) in a furnace to allow for diamond oxidation to occur, which results in improved diamond surface roughness. Pad conditioners are then fabricated using different degrees of diamond sharpness. Using this result, the pad cut rates are studied by comparing them with conventional diamond disks. The friction force between pad and wafer and polishing rates of silicon dioxide using the new pads are also studied. The experimental results reveal that the wafer removal rate and pad cut rate of the new diamond disk are higher than those of conventional diamond disks, and the number of diamond grits required is significantly low. Roughly 6,000 diamond grits are used in the newly designed disk as compared to 10,000 in conventional diamond disks. The new design can therefore be expected to reduce the cost of diamond disks. It was found that wafer removal rate correlates well with the variation of the coefficient of force. In addition, a higher wafer removal rate is obtained by diamond oxidation at a temperature of 900℃. This result can facilitate the development of a more efficient diamond disk in the future.