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US 8,507,362 B2Granted
Process of forming ultra thin wafers having an edge support ring
AssigneeAlpha and Omega Semiconductor Incorporated
InventorsTao Feng, Sung-Shan Tai
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Abstract
A process of forming ultra thin wafers having an edge support ring is disclosed. The process provides an edge support ring having an angled inner wall compatible with spin etch processes.
Claims2
A process of forming an ultra thin wafer having an edge support ring comprising the steps of:
- positioning a grinding wheel proximate a wafer backside edge;
- grinding a periphery of the wafer backside while gradually reducing a distance between a grinding wheel axis of rotation and a wafer chuck axis of rotation, wherein the grinding wheel axis of rotation is parallel to the wafer chuck axis of rotation;
- gradually decreasing feed depth of said grinding wheel as a function of said decrease in said distance between said wheel axis of rotation and said wafer chuck axis of rotation to create an ultra thin central portion and a peripheral edge support ring with an angled inner wall;
- and
- ending the grinding of the wafer backside when an ultra thin central portion thickness is achieved.
2 more elements
Dependencies are inferred from the claim text.