Papers by Author: N. Qin

Abstract: The calculating model of surface non-uniformity of polishing pad and the kinematical model between polishing pad and conditioner are initially established. Then the effects of several conditioning parameters were investigated by using the two models. The results of simulation and calculation show that the width ratio of diamond band of conditoner and the rotation speed at the same speed ratio between pad and conditioner have little effect on the surface non-uniformity of polishing pad, while at high non-integer rotation speed ratio, the surface non-uniformity of polishing pad is better than that at low integer speed ratio. The research results are available to select appropriate conditioning parameters especially for the stringent requirement of within-wafer non-uniformity in next generation IC.

Abstract: Among the properties of polishing pad, the surface roughness plays a crucial role in CMP (Chemical Mechanical Planarization) process. However, there is no acknowledged standard for measuring and characterizing the roughness of pad surface in 3D measurement. In this paper Talysurf CLI 2000 working on the principle of dynamic confocal measurement was initially suggested to measure the 3D surface topography of polishing pads through theoretical and experimental analysis. In addition, based on the Nyquist folding frequency and the statistical theory, a selection technique for sampling interval and sampling area was proposed and verified through experiments. The results showed that Talysurf CLI 2000 is more suitable than NewView to measure the 3D surface topography of polishing pads. 2μm sampling interval, 0.5×0.5mm2 sampling area and 10μm interval, 1×1mm2 area are respectively recommended for IC1000/SubaIV and SubaIV polishing pad.