Wafer carrier and chemical mechanical polishing apparatus including the same

Abstract

Disclosed are a wafer carrier assembly and a chemical mechanical polishing apparatus including the same. The present wafer carrier for a chemical mechanical polishing apparatus comprises: a wafer carrier head rotatably mounted on the apparatus, having a lower surface for contacting a wafer; a retaining ring attached to the lower surface of the wafer carrier head, for retaining or preventing the wafer from moving from the wafer carrier head during rotational motion thereof; and a guard ring attached to the lower surface of the wafer carrier head a distance outside the retaining ring.

Description

[0001] This application claims the benefit of Korean Application No. 10-2005-0039779, filed on May 12, 2005, which is incorporated by reference herein in its entirety. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to an apparatus for chemical mechanical polishing of a semiconductor wafer. More specifically, the present invention relates to a wafer carrier assembly for use in a chemical mechanical polishing apparatus. [0004] 2. Description of the Related Art [0005] Chemical-mechanical polishing (CMP) process plays an important role in high-integration and ultraminiaturization of a semiconductor device. Typically, a semiconductor device including high density circuits requires closely spaced multilevel metallization lines. Thus, a poor surface planarity of a semiconductor wafer exerts a bad influence upon interconnection between metallization lines. CMP technology has been developed as demand for a global planarization of a semicondu...

AI Technical Summary

Benefits of technology

The present invention provides a wafer carrier assembly and a chemical mechanical polishing apparatus that can prevent the periphery of a semiconductor wafer from being overpolished during a chemical mechanical polishing process. The wafer carrier assembly includes a wafer carrier head, a retaining ring, and a guard ring. The retaining ring is attached to the wafer carrier head and retains the wafer during rotational motion. The guard ring is attached to the wafer carrier head and is positioned outside of the retaining ring. The inner wall of the retaining ring is in contact with the periphery of the wafer, and the protrusion height of the guard ring is substantially equal to or larger than that of the retaining ring. The bottom surface of the retaining ring is positioned on the same plane as the polished surface of the wafer. The chemical mechanical polishing apparatus includes a turntable, a polishing pad, a wafer carrier support frame, a wafer carrier rotatably mounted on the wafer carrier support frame, and a slurry providing unit. The wafer carrier includes a wafer carrier head, a retaining ring, and a guard ring. These features prevent the wafer from being overpolished and improve the polishing process.

Problems solved by technology

Thus, a poor surface planarity of a semiconductor wafer exerts a bad influence upon interconnection between metallization lines.

As a result, the polished surface of wafer becomes uneven or non-uniform, which may decrease the yield of semiconductor devices from the wafer.

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