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:
Aug. 26, 2014
Filed:
Feb. 28, 2011
Elizabeth Ann Dobisz, San Jose, CA (US);
Ricardo Ruiz, Santa Clara, CA (US);
Guoliang Liu, Madison, WI (US);
Paul Franklin Nealey, Madison, WI (US);
Elizabeth Ann Dobisz, San Jose, CA (US);
Ricardo Ruiz, Santa Clara, CA (US);
Guoliang Liu, Madison, WI (US);
Paul Franklin Nealey, Madison, WI (US);
HGST Netherlands B.V., Amsterdam, NL;
Abstract
A method for making a master mold used to nanoimprint patterned magnetic recording disks that have chevron servo patterns with minimal defects uses directed self-assembly of block copolymers. A pattern of chemically modified polymer brush material is formed on the master mold substrate. The pattern includes sets of slanted stripes and interface strips between the sets of slanted stripes. A block copolymer material is deposited on the pattern, which results in directed self-assembly of the block copolymer as lamellae perpendicular to the substrate that are formed into alternating slanted stripes of alternating first and second components of the block copolymer. This component also forms on the interface strips, but as a lamella parallel to the substrate. One of the components is then removed, leaving the remaining component as a grid that acts as a mask for etching the substrate to form the master mold. The disks nanoimprinted by the master mold have reduced defective areas in the transition regions of the chevron servo patterns.