Number | Date | Country | Kind |
---|---|---|---|
1-310693 | Dec 1989 | JPX | |
1-310694 | Dec 1989 | JPX | |
1-310695 | Dec 1989 | JPX | |
2-59930 | Mar 1990 | JPX |
Number | Name | Date | Kind |
---|---|---|---|
5045417 | Okamoto | Sep 1991 |
Number | Date | Country |
---|---|---|
57-62052 | Apr 1982 | JPX |
Entry |
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Levenson et al., "Improving Resolution In Photolithography With A Phase-Shifting Mask", Dec. 1982, pp. 1828-1836. |