Wafer carrier for semiconductor wafer polishing machine
AssigneeSpeedfam Corporation
InventorJohn Natalicio
Life of this patent
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Abstract
A carrier assembly for use in the processing of semiconductor wafers which avoids the use of a gimbal mechanism. The wafer carrier assembly comprises a backing pad for the wafer, with the wafer and backing pad secured within a retaining ring, such that the retaining ring, wafer, and backing pad move as single, integral assembly. A resiliently flexible outer housing terminates in a pad load ring transmits the rotation of the drive shaft to the load plate while allowing limited axial movement between the outer ring and inner ring assembly. The wafer/load plate assembly is permitted to float within the outer ring while the outer ring locally depresses the polishing pad near the wafer periphery, to mitigate edge exclusion.
Claims23
A workpiece carrier assembly, comprising:
- a resiliently deformable, flexible outer housing having an inner hub rigidly secured thereto, said outer housing being releasably coupled to a rotatable shaft;
- a carrier having a lower surface configured to conform to an upper surface of a workpiece, and an upper surface upon which pressure is applied to urge said workpiece into sliding engagement with a polishing surface;
- an inner retaining ring configured to retain said workpiece within said carrier assembly during said sliding engagement with said polishing surface;
- an outer retaining ring, rigidly secured to said deformable housing, configured to depress said polishing surface in the vicinity of said outer retaining ring;
- wherein said inner retaining ring, said carrier, and said workpiece are configured to float as an integral unit with respect to said outer retaining ring.
A carrier assembly for a workpiece comprising:
- an outer housing;
- a load plate assembly for carrying said workpiece and pressing said workpiece against said polishing surface;
- and a valving assembly configured to apply low pressure to an upper surface of said load plate assembly to press said load plate assembly downward and said workpiece into contact with said polishing surface, high pressure to a lower surface of said load plate assembly to discharge said workpiece, and vacuum pressure to said lower surface to retain said workpiece.
Dependencies are inferred from the claim text.