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:
May. 15, 2001
Filed:
Oct. 21, 1999
Applicant:
Inventor:
Claymens Lee, Kaohsiung Hsien, TW;
Assignee:
United Microelectronics Corp., Hsinchu, TW;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 2/1336 ;
U.S. Cl.
CPC ...
H01L 2/1336 ;
Abstract
A method of forming flash memory. The method includes forming buried bit lines before the production of shallow trench isolation (STI) structures. The steps for producing the STI structures include forming a pad oxide layer and a silicon nitride layer. A plurality of openings that expose the pad oxide layer is formed in the silicon nitride layer. These openings are located directly above the buried bit lines. Silicon dioxide is deposited to form a silicon dioxide layer that fills these openings. The silicon dioxide layer is capable of preventing the buried bit lines from being cut into segments in subsequent trench-isolation operations.