Patent Number: 6,166,943

Title: Method of forming a binary code of a ROM

Abstract: The present invention provides a method of writing a set of binary codes into a ROM. The method is performed by forming a first photo mask and a second photo mask according to an original first code pattern, an original second code pattern, and a set of binary codes to be written into the ROM. Final first and second code patterns are formed by coupling the binary codes to be written with the original first and second code patterns by using a Boolean logical OR operation. The first and second photo masks are formed according to the final first and second code patterns. The first photolithographic process is performed using the first photo mask, and the first ion implantation process is performed; the second photolithographic process is performed using the second photo mask, and the second ion implantation process is performed. Thus the set of binary codes is written into the ROM completely and correctly.

Inventors: Wang; Ping-Ying (Hsin-Chu, TW), Yang; Chun-Yi (Hsin-Chu Hsien, TW), Lin; Chun-Jung (Hsin-Chu, TW), Chang; Jui-Chin (Tai-Chung Hsien, TW), Wang; Mam-Tsung (Hsin-Chu, TW)

Assignee: Macronix International Co, Ltd

International Classification: G11C 17/08 (20060101); G11C 17/10 (20060101); G11C 017/00 ()

Expiration Date: 12/26/2017