| 摘要 |
A polishing agent delivery system for a wafer processing system includes multiple tanks each of which can hold a supply of a respective polishing agent constituent, such as a slurry constituent, a buffing agent or a cleansing agent. The system also includes multiple containers, each one of which can hold a respective polishing agent constituent. Additionally, each container has a motor-driven piston that can be operated to cause the respective polishing agent constituent to be dispensed from the container to a wafer processing station and which can be operated to cause additional polishing agent constituent to be drawn into the container from a corresponding one of the tanks. The apparatus also includes a controller for controlling a respective rate of linear displacement of each motor-driven piston. Stepper motors or servo-motors can be used. The system allows changes to slurry mixtures to be made quickly and efficiently, and different slurry or buffing mixtures can be used for different polishing stations. Furthermore, the system can provide tight control over the dispensing operations so that precise, predetermined amounts of each constituent are mixed into the slurry. The system is highly modular which can facilitate the delivery of slurry or other polishing agents to additional polishing stations. The rate at which various polishing agent constituents are delivered to a wafer polishing station can be altered dynamically during a wafer polishing cycle or between cycles.
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