Abstract
As ULSI feature dimensions continue to shrink, and the number of interconnect layers increases from 4 to 8, the resulting surface topography causes serious problems in device patterning. CMP has become a standard technology used in semiconductor manufacturing to planarize the surface topography. We have developed an oscillation-speed-control-type sequential grinding and polishing machine and have proceeded to simulate the polishing process. A previous paper showed theoretically that it is possible to polish within±1% uniformity with the optimum oscillation speed control. This paper presents removal rates measured under high relative velocity and high pressure, and a comparison between experiment and simulation for polishing profiles. It is shown that the removal rate begins to saturate gradually from low relative velocity and that Preston's equation can be used under high pressure caused when the tool overhangs from the wafer. In addition, the experimental result of profiles polished at normal and reverse rotations with disc and ring tools agreed well with the simulation result calculated with a modified equation of relative velocity under high velocity. However, it did not agree when the tool overhung the wafer by a significant amount.
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