Real-time monitoring of retaining ring thickness and lifetime

Abstract

A method and apparatus for monitoring the condition of a surface of a retaining ring disposed on a carrier head in a polishing module is described. In one embodiment, a method for monitoring at least one surface of a retaining ring coupled to a carrier head is provided. The method includes moving the carrier head adjacent a sensor device disposed in a polishing module, transmitting energy from the sensor device toward the retaining ring, receiving energy reflected from the retaining ring, and determining a condition of the retaining ring based on the received energy.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]Embodiments of the invention relate to polishing systems for polishing a substrate, such as a semiconductor substrate. More particularly, to a method and apparatus for monitoring components of a polishing system.[0003]2. Description of the Related Art[0004]Chemical mechanical polishing (CMP) is one process commonly used in the manufacture of high-density integrated circuits to planarize or polish a layer of material deposited on a substrate. The substrate may be provided to a polishing station on a polishing system and retained in a carrier head that controllably urges the substrate against a moving polishing pad. CMP is effectively employed by providing contact between a feature side of the substrate and moving the substrate relative to the polishing pad while in the presence of a polishing fluid. Material is removed from the feature side of the substrate that is in contact with the polishing surface through a combinat...

AI Technical Summary

Benefits of technology

[0012]In another embodiment, a transfer station disposed in a polishing module for transferring substrates between a substrate transfer device and at least one carrier head is provided. The transfer station includes a load cup assembly having a body that is sized to receive a substrate and at least a portion of a retaining ring that is coupled to the at least one carrier head, and a sensor disposed on the body, the sensor operable to provide a metric indicative of a condition of the retaining ring, wherein the substrate includes a first radius and the sensor is positioned on the body at a second radius that is greater than the first radius.

Problems solved by technology

While the retaining ring is adapted to endure polishing of multiple substrates, the surfaces that are in contact with the polishing pad experience wear and periodic replacement of the retaining ring is necessary.

The conventional inspection methods are time-consuming, require personnel to physically handle components in the station and requires shutdown of the polishing system.

Additionally, the conventional methods may require partial disassembly of the polishing station and removal of the carrier head from the station, which may expose other components within the system to contamination.

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