The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 21, 2003
Filed:
Feb. 15, 2000
Ashok Lahiri, Mainz, DE;
Edward Hin Pong Lee, San Jose, CA (US);
Eric James Lee, San Jose, CA (US);
Hong Xu, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The thin film magnetic head of the present invention includes an improved P pole tip/yoke interface structure. The interface structure includes yoke material that is formed in a concave curved shape at the interface between the P pole tip and the yoke, such that a right angle interface between the P pole tip and the yoke is eliminated. The process for forming the P pole tip/yoke interface includes a second CMP polishing step that is performed on the surface of the write head wafer subsequent to the plating of the P pole tip thereon, and subsequent to a first CMP step. This second CMP step utilizes a relatively soft polishing pad and an acidic polishing slurry having a pH within the range of approximately 1 to approximately 5, and preferably approximately 2.5. The acidic polishing slurry contains a chemical agent which preferentially attacks the P pole tip material, such that the second CMP step results in the recession of the upper surface of the P pole tip relative to the dielectric layer surrounding it, as well as the significant rounding of the upper edges of the dielectric trench in which the P pole tip is formed. Thereafter, when the yoke is plated onto the P pole tip the rounded upper edges of the dielectric trench result in a concave curved interface between the yoke and the P pole tip. The resulting P pole tip/yoke interface possesses improved magnetic flux flow control properties and results in decreased side writing. Greater track per inch areal data storage results from the reduced side writing of the improved write head.