Patent Number: 7,824,245

Title: Automated chemical polishing system adapted for soft semiconductor materials

Abstract: At least one wafer is suspended on a respective jig shaft above a polishing platen. The degree of parallelism between the wafer and the polishing platen is controlled using a three-point suspension, which allows for planar pitch adjustments using vertical actuation algorithms. As the wafer is lowered into contact against the polishing platen, a load cell senses how much of the weight of the jig shaft, wafer mount and wafer continues to be supported by the jig. The vertical displacement of the wafer is controlled using a linear actuator responsive to a signal from the load cell. Vertical actuation of the wafer serves to increase or decrease this amount of supported weight, in turn decreasing or increasing the amount of applied downforce exerted between the wafer and the platen. A compression spring is used to increase the resolution of the pressure control. Finally, system components exposed to the work environment are encapsulated by chemically resistive components to prevent corrosion of system components.

Inventors: Crocco; Jerome (Chicago, IL), Singh; Rasdip (Palos Hills, IL)

Assignee: EPIR Technologies, Inc.

International Classification: B24B 7/22 (20060101)

Expiration Date: 2019-11-02 0:00:00