| 摘要 |
<p>A phase-shifting mask (400) is provided with a pattern which comprises a plurality of substantially transparent regions (402, 404, 406) and a plurality of substantially opaque regions (410, 412, 414, 416). Phase-shifters (420, 422) extend over apertures (402) and (404) respectively. Phase-shifter (420) produces a <SP>2</SP>/<SB>3</SB> pi radian shift (120 degrees) and phase-shifter (422) produces a <SP>4</SP>/<SB>3</SB> pi radian shift (240 degrees). Incident radiation does not undergo a phase shift on passing through aperture (406). Phase-shifting mask (400) is a three-phase-shifting mask. Electric fields (440, 442, 444) from apertures (402, 404, 406) resp. at a workpiece surface are shown in Figure 4C. The electric fields at the overlap regions are added destructively and the intensity is substantially zero where images through apertures (402, 404, 406) meet on the workpiece surface, therefore increasing resolution. Figure 4E shows electric field vectors corresponding to an electric field at workpiece level for mask (400).</p> |
