Novel diamond conditioner dressing characteristics of CMP polishing pad

摘要

A diamond pad conditioner or dresser is required to regenerate the asperity structure of a pad used in chemical mechanical polishing (CMP). A conventional diamond dresser (CDD) is made by attaching discrete diamond grits to the flat surface of a substrate. Although the CDD has regularly distributed diamond grits, the tips of diamond grits are not leveled to the same height. Additionally, diamond grits have different shapes and orientations. A newly designed diamond conditioner, called the advanced diamond dresser (ADD), is made by sculpting a sintered polycrystalline diamond substrate to form identically shaped tips with diamond pieces of equal height, rather than by attaching individual diamond grits to a metal substrate. The dressing characteristics of pad surface textures are compared with those of a CDD. Experimental results reveal that the ADD can create asperities of the pad more uniformly than the CDD. Not only the dressing rate of the ADD is reduced by about 30% but also the stable pad surface texture is formed more quickly than the dressing can be performed using the CDD, extending pad life. The polishing rate of the ADD exceeds that of the CDD. The polishing rate varies with the polishing time, which is less for ADD than for CDD.