| 摘要 |
1323647 Photo-masks INTERNATIONAL BUSINESS MACHINES CORP 19 April 1971 [17 Feb 1970] 21760/71 Heading G2M A photo-mask for preparing semi-conductor integrated circuits comprises a circuit pattern disposed on a borosilicate glass support member. A master mask may be made by a step and repeat camera and used to contact print a submaster which in turn is used to contact print a workplate mask, the 2 masters and the mask all having borosilicate glass supports. |
