| 摘要 |
PURPOSE: An exposure mask manufactured by attaching a curvature smoother to existing mask to compensate variation of critical dimensions in one shot and alteration of focus caused from field curvature is proposed for ensuring uniformity of patterns in shot when it is exposed. CONSTITUTION: An exposure mask is composed of a transparent substrate, a certain shielding film pattern to block light presented on the substrate and a curvature smoother attached to the substrate and having an irregular thickness to derive difference of light paths and formed of a material to transmit light. The transparent substrate has the shielding film with defined pattern at its lower end. The shielding film is formed in a desired thickness by conductive materials such as Cr and CrOx. During the exposure process, the light transmitted from light source is passed through an area for transmitting light and projected on a wafer coated with a photosensitive film. |
