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. 13, 1996
Filed:
Sep. 19, 1995
Applicant:
Inventors:
Assignee:
United Microelectronics Corporation, Hsinchu, TW;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437 48 ; 437 45 ; 437154 ;
Abstract
A multi-state read-only-memory device and a method for fabricating the same is suitable for forming on a semiconductor substrate. The read-only memory device is provided with bit lines and word lines which are mutually intersecting. In accordance with the present invention, multiple polysilicon selective deposition procedures are utilized to form a plurality of protrusion portions onto the word lines but with multiple thicknesses. Then, one implantation procedure is applied to program the device into multiple states at the same time without incurring misalignment problems that result in inaccuracy.