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:
Nov. 25, 2008
Filed:
Nov. 23, 2005
Sukhbir Singh Dulay, San Jose, CA (US);
Justin Jia-jen Hwu, San Jose, CA (US);
Thao John Pham, San Jose, CA (US);
Sukhbir Singh Dulay, San Jose, CA (US);
Justin Jia-Jen Hwu, San Jose, CA (US);
Thao John Pham, San Jose, CA (US);
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
A method for measuring recession in a wafer undergoing an asymmetrical ion mill process. The method includes the formation of first and second reference features and possibly a dummy feature. The reference features are constructed such that the location of the midpoint between them is unaffected by the asymmetrical ion mill. By measuring the distance between a portion of the dummy feature and the midpoint between the reference features, the amount of recession of the dummy feature can be measured. The measurement can be used to calculate the relative location of the flare to the read sensor rear edge through overlay information. By keeping the angles of the sides of the features steep (ie. nearly parallel with the direction in which the ion mill is asymmetrical) the amount of material consumed on each of the reference features is substantially equal and the midpoint between the reference features is substantially stationary.