Mram wet etch method
AssigneeInternational Business Machines Corporation
InventorsEugene J. O'Sullivan, Daniel Worledge
Life of this patent
Estimating the term…
Abstract
An etching process is employed to selectively pattern the top magnetic film layer, the tunnel barrier, and the pinned bottom magnetic layer of a magnetic thin film structure. The pinned bottom magnetic film layer has an antiferromagnetic layer or a Ru spacer formed thereunder. The etching process employs various etching steps that selectively remove various layers of the magnetic thin film structure stopping on the antiferromagnetic layer or the Ru spacer. The progress of this etching process can be monitored by measuring the electrochemical potential difference of a part or wafer containing a magnetic structure with respect to a reference electrode simultaneously with the selective etching process.
Claims20
A method of monitoring the progress of a selective etching process and determining the etch endpoint of said selective etching process comprising measuring the electrochemical potential difference of a part or wafer containing a magnetic structure with respect to a reference electrode simultaneously with the selective etching process.
Dependencies are inferred from the claim text.