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:
Oct. 01, 2013
Filed:
Jul. 18, 2012
Isao Tanaka, Taichung, TW;
Chien-hua Tsai, Taichung, TW;
Isao Tanaka, Taichung, TW;
Chien-hua Tsai, Taichung, TW;
Rexchip Electronics Corporation, Taichung, TW;
Abstract
A method for fabricating buried bit lines comprises steps of: defining a plurality of parallel masked regions and a plurality of first etched regions each forming between any two neighboring masked regions on a surface of a substrate, and wherein the masked region is wider than the first etched region; etching the first etched regions to form a plurality of first trenches and a plurality of first pillars; forming two bit lines respectively on two sidewalls of each first trench; etching the first pillars to form a plurality of second pillars corresponding to the bit lines. The present invention uses a two-stage etching process to prevent pillars from bending or collapsing due to high aspect ratio. Moreover, the present invention has a simple process and is able to reduce cost and decrease cell size.