| 摘要 |
<p>A system and method of avoiding pattern shortening without resorting to generating a mask with a bias solve the direction dependent differences in exposure behavior in photolithography processes in the manufacture of semiconductor devices. Instead of designing a biased mask to solve the exposure problem, the pattern shortening effect is avoided by influencing the exposure process itself. By using an off axis illumination technique, the exposure is separated into different directions. In one embodiment, off axis illumination is applied in combination with special dipole apertures (i.e., two openings). The exposure is done in two or more parts, whereby the dipole aperture (12) is rotated between exposures. In another embodiment, off axis illumination is used in combination with special polarizer apertures. As with the first embodiment, the exposure is done in two or more parts, but in this case with differently polarized light.</p> |
