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US 2010/0141292 A1Published application
Method and system for measuring film stress in a wafer film
AssigneeNational Semiconductor Corporation
InventorPeter J. Hopper
Life of this patent
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Abstract
In a MEMS wafer, film stresses are measured by placing an inductor array over or under the wafer and measuring inductance variations across the array to obtain a map defining the amount of bowing of the wafer.
Claims18
A method of measuring the film stress of a film deposited on a silicon wafer, the combination defining a conductive wafer, comprising
- placing an inductor array over or under the conductive wafer and monitoring the eddie current coupling of the inductors in the array with the conductive wafer.
An inductor array comprising
- a flat platen, and
- multiple inductors formed on the platen by metallization and contact printer lithographic techniques, wherein the platen and inductors are encapsulated to define a flattened capsule.
Dependencies are inferred from the claim text.