Importance

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Abstract

Specific embodiments of the present invention provide a chemical-mechanical planarization apparatus for planarizing an object comprising a shaft having a shaft axis and being connected with a polishing head which is coupled to a polishing pad. The polishing pad has a smaller diameter than the object to be planarized. The shaft is rotatable to spin the polishing head and polishing pad around the shaft axis. An orbit housing has, spaced from an orbital axis, an eccentric hole through which the shaft is rotatably disposed. The orbit housing is rotatable to orbit the shaft, the polishing head, and the polishing pad around the orbital axis. In some embodiments, the object is rotated at an object rotational speed and the polishing pad is rotated around the orbital axis at an orbiting speed. A ratio of the greater of the object rotational speed and the orbiting speed to the lesser of the object rotational speed and the orbiting speed is a non-integer. The orbiting speed may be greater than the object rotational speed. In some embodiments, the polishing pad is rotated around the shaft axis at a spinning speed and is rotated around the orbital axis at an orbiting speed. The orbiting speed is greater than the spinning speed when the polishing pad is contacted with a center region of the surface of the object. In a specific embodiment, the spinning speed is approximately zero when the polishing pad is contacted with the center region. In some embodiments, the spinning speed is greater than the orbiting speed when the polishing pad is contacted with an edge region of the surface of the object. In a specific embodiment, the orbiting speed is approximately zero when the polishing pad is contacted with the edge region.

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First Claim