Mono crystalline silicon wafers are important materials in the semiconductor industry for fabricating integrated circuits and micro electro mechanical systems. To ensure high surface integrity of polished wafers, the effect of pad texture and its variation on the pad performance needs to be understood. This paper studies experimentally the dependence of pad performance on its texture deterioration by investigating its correlation with polishing time, polishing pressure, and material removal rate. The study concludes that material removal rate decreases as the cylindrical cell structure of a pad is gradually deteriorated, that there is a pad life limit beyond which polishing quality can no longer be maintained, and that the workable pad life can be extended to a certain degree by applying higher polishing pressure.
Read Full Article