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:
Dec. 10, 2013
Filed:
Jan. 14, 2011
Chao-peng Cheng, Fremont, CA (US);
Chih-i Yang, San Jose, CA (US);
Jas Chudasama, Milpitas, CA (US);
William Stokes, Milpitas, CA (US);
Chien-li Lin, Fremont, CA (US);
David Wagner, San Jose, CA (US);
Chao-Peng Cheng, Fremont, CA (US);
Chih-I Yang, San Jose, CA (US);
Jas Chudasama, Milpitas, CA (US);
William Stokes, Milpitas, CA (US);
Chien-Li Lin, Fremont, CA (US);
David Wagner, San Jose, CA (US);
Headway Technologies, Inc., Milpitas, CA (US);
Abstract
A method of removing an alumina layer around a main pole layer during perpendicular magnetic recording head fabrication is disclosed. The alumina etch sequence includes immersing a substrate in a series of aqueous solutions purged with an inert gas to remove oxygen thereby avoiding corrosion of the main pole. Initially, the substrate is soaked and heated in deionized (DI) water. Once heated, the substrate is immersed in an etching bath at about 80° C. and pH 10.5. Bath chemistry is preferably based on NaCOand NaHCO, and Npurging improves etch uniformity and reduces residue. Thereafter, the substrate is rinsed in a second DI water bath between room temperature and 80° C., and finally subjected to a quick dump rinse before drying. Inert gas, preferably N, may be introduced into the aqueous solutions through a purge board having a plurality of openings and positioned proximate to the bottom of a bath container.