| 摘要 |
<p>A method for improving the imaging performance in a photolithographic system having a pupil plane and using a phase shift mask. A portion of the pupil plane where a phase error portion of a light from the phase shift mask is located. An aperture is placed at the located portion of the pupil plane. Typically, the phase error portion of the light from the phase shift mask is a zero order portion of the light often referred to as "zero order leakage". Blocking the zero order leakage significantly mitigates the variations in the intensity of the light that exposes photoresist that is above or below the nominal focal plane. This, in turn, reduces the variations in the linewidths formed on the wafer. <IMAGE></p> |
