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. 05, 2005
Filed:
Oct. 06, 2003
Tung-cheng Kuo, Yilan Hsien, TW;
Chien-hung Liu, Taipei, TW;
Shyi-shuh Pan, Kaohsiung, TW;
Shou-wei Huang, Chilung, TW;
Tung-Cheng Kuo, Yilan Hsien, TW;
Chien-Hung Liu, Taipei, TW;
Shyi-Shuh Pan, Kaohsiung, TW;
Shou-Wei Huang, Chilung, TW;
Macronix International Co., Ltd., Hsinchu, TW;
Abstract
An ultraviolet-programmable P-type Mask ROM is described. The threshold voltages of all memory cells are raised at first to make each memory cell to be in a first logic state, in which the channel is hard to switch on, in order to prevent a leakage current. After the bit lines and the word lines are formed, the Mask ROM is programmed by irradiating the substrate with UV light to inject electrons into the ONO layer under the openings to make the memory cells under the openings be in a second logic state.