| US 7,579,121 B2 | ||
| Optical proximity correction photomasks | ||
| Ching-Yu Chang, Yilang County (Taiwan) | ||
| Assigned to Taiwan Semiconductor Manufacturing Co., Ltd., Hsin-Chu (Taiwan) | ||
| Filed on Oct. 07, 2005, as Appl. No. 11/245,522. | ||
| Prior Publication US 2007/0082275 A1, Apr. 12, 2007 | ||
| Int. Cl. G03F 1/00 (2006.01); G03F 1/14 (2006.01) | ||
| U.S. Cl. 430—5 | 14 Claims |
| 1. An optical proximity correction photomask, comprising:
a transparent substrate;
a main feature having a first transmitivity disposed on the transparent substrate;
at least one assist feature having a second transmitivity disposed to each side of the main feature and on the transparent
substrate, wherein the first transmitivity is not equal to the second transmitivity,
wherein the transparent substrate further comprises a semi-transparent layer having a first trench serving as the main feature
and at least one second trench serving as the at least one assist feature, the first trench exposing the transparent substrate
and the at least one second trench formed within the semi-transparent layer.
|