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:
Apr. 04, 2000
Filed:
Sep. 25, 1997
Applicant:
Inventors:
Tao Cheng Lu, Kaohsiung, TW;
Mam-Tsung Wang, Hsin-chu, TW;
Assignee:
Macronix International Co., Ltd., Hsinchu, TW;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
257390 ; 257391 ; 257411 ;
Abstract
A mask read-only-memory cell structure without ROM code implantation is presented. By using double polysilicon technology, ROM code cells which store data '0' can be replaced by cells with double polysilicon layers and an insulating layer between them. Normal cells with double polysilicon layers but without an insulating layer between them form normal cells store data '1'. According to the invention, further scaling of mask ROM is possible and operating condition can be released because of high junction breakdown voltage. Furthermore, the double polysilicon technology makes redundancy circuit more easily to implement.