| 摘要 |
PURPOSE:To increase the depth of focus in the lithography step of semiconductor fabrication process. CONSTITUTION:A first photoresist film 3 is applied onto a film 2 to be micromachined and a second photoresist film 4, which is evaporated by the exposing light to decrease the thickness, is applied thereon. The second photoresist film 4 forms a concave lens during exposure thus increasing the depth of focus. |
